Please Cc me for the next versions. On 27/09/2022 21:53, Casey Schaufler wrote: [...] Please only use one space after ".lsm". This applies for other commits as well. This command will do the trick: FILTER_BRANCH_SQUELCH_WARNING=1 git filter-branch --tree-filter "clang-format-14 -i security/landlock/*.[ch]" v6.0-rc7..

On 3/3/2023 7:17 AM, Georgia Garcia wrote: Yes. Thank you for the review.

On 27/09/2022 21:53, Casey Schaufler wrote: What do you have in mind? Why not "reserve" higher bits instead and start with SELinux at 1? Out of curiosity, why this order? Please only use one space after ".id"

On Tue, 2022-09-27 at 12:53 -0700, Casey Schaufler wrote: Reviewed-by: Georgia Garcia <georgia.garcia(a)canonical.com&gt;

As LSMs are registered add their lsm_id pointers to a table. This will be used later for attribute reporting. Signed-off-by: Casey Schaufler <casey(a)schaufler-ca.com&gt; --- include/linux/security.h | 17 +++++++++++++++++ security/security.c | 18 ++++++++++++++++++ 2 files changed, 35 insertions(+) diff --git a/include/linux/security.h b/include/linux/security.h index 7bd0c490703d..abdd151fc720 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -136,6 +136,23 @@ enum lockdown_reason { extern const char *const lockdown_reasons[LOCKDOWN_CONFIDENTIALITY_MAX+1]; +#define LSMID_ENTRIES ( \ + 1 + /* capabilities */ \ + (IS_ENABLED(CONFIG_SECURITY_SELINUX) ? 1 : 0) + \ + (IS_ENABLED(CONFIG_SECURITY_SMACK) ? 1 : 0) + \ + (IS_ENABLED(CONFIG_SECURITY_TOMOYO) ? 1 : 0) + \ + (IS_ENABLED(CONFIG_SECURITY_IMA) ? 1 : 0) + \ + (IS_ENABLED(CONFIG_SECURITY_APPARMOR) ? 1 : 0) + \ + (IS_ENABLED(CONFIG_SECURITY_YAMA) ? 1 : 0) + \ + (IS_ENABLED(CONFIG_SECURITY_LOADPIN) ? 1 : 0) + \ + (IS_ENABLED(CONFIG_SECURITY_SAFESETID) ? 1 : 0) + \ + (IS_ENABLED(CONFIG_SECURITY_LOCKDOWN) ? 1 : 0) + \ + (IS_ENABLED(CONFIG_BPF_LSM) ? 1 : 0) + \ + (IS_ENABLED(CONFIG_SECURITY_LANDLOCK) ? 1 : 0)) + +extern int lsm_id; +extern struct lsm_id *lsm_idlist[]; + /* These functions are in security/commoncap.c */ extern int cap_capable(const struct cred *cred, struct user_namespace *ns, int cap, unsigned int opts); diff --git a/security/security.c b/security/security.c index ff7fda4ffa43..14f22d9c9d84 100644 --- a/security/security.c +++ b/security/security.c @@ -28,6 +28,7 @@ #include <linux/backing-dev.h> #include <linux/string.h> #include <linux/msg.h> +#include <uapi/linux/lsm.h> #include <net/flow.h> #define MAX_LSM_EVM_XATTR 2 @@ -318,6 +319,12 @@ static void __init lsm_early_task(struct task_struct *task); static int lsm_append(const char *new, char **result); +/* + * Current index to use while initializing the lsm id list. + */ +int lsm_id __lsm_ro_after_init; +struct lsm_id *lsm_idlist[LSMID_ENTRIES] __lsm_ro_after_init; + static void __init ordered_lsm_init(void) { struct lsm_info **lsm; @@ -362,6 +369,7 @@ static void __init ordered_lsm_init(void) for (lsm = ordered_lsms; *lsm; lsm++) initialize_lsm(*lsm); + init_debug("lsm count = %d\n", lsm_id); kfree(ordered_lsms); } @@ -483,6 +491,16 @@ void __init security_add_hooks(struct security_hook_list *hooks, int count, { int i; + /* + * A security module may call security_add_hooks() more + * than once. Landlock is one such case. + */ + if (lsm_id == 0 || lsm_idlist[lsm_id - 1] != lsmid) + lsm_idlist[lsm_id++] = lsmid; + + if (lsm_id > LSMID_ENTRIES) + panic("%s Too many LSMs registered.\n", __func__); + for (i = 0; i < count; i++) { hooks[i].lsmid = lsmid; hlist_add_tail_rcu(&hooks[i].list, hooks[i].head); -- 2.37.3

On 10/13/2022 3:04 AM, Tetsuo Handa wrote: I don't see any way given the locking issues that we're ever going to mix built in security modules and loaded security modules on the same hook lists. The SELinux module deletion code is sufficiently scary that it is being removed. That does not mean that I think loadable modules are impossible, I think it means that their management is going to have to be separate, the same way the BPF programs are handled. The only way that I see a unified hook list is for all the LSMs to be implemented as loadable modules, and I can't see that happening in my lifetime. I can see an LSM like BPF, as I mentioned before, that manages loaded modules. Over the years I've seen several designs that might work. I'm encouraged (and not a little bit frightened) by the success of the BPF work. Converting the array[LSMID_ENTRIES] implementation to a hlist like the hooks have used would not be that big a project and I don't see that making such a change would be a show-stopper for implementing loadable modules. I think that a lot of other issues would be more significant. I will, on the other hand, listen to compelling arguments. It is not the intention of this code to lock out loadable modules. If I thought it would I would not have proposed it. While the proposed set of attributes map to those in /proc/.../attr there is no reason to assume they will be limited to those. I can see providing several of the Smack attributes currently manipulated in smackfs, such as relabel-self. If we are providing SELinux specific values like keycreate there's no reason we can't provide Smack or TOMOYO specific values as well.

On 10/23/2022 12:27 AM, Tetsuo Handa wrote: I don't see that having a built-in version of TOMOYO and a loadable version needs to be difficult. That's something that whoever creates the loadable security module scheme is going to have to address. It will depend on the details of the loadable module mechanism. I can't comment on how that will work because I don't see loadable modules hitting the top of my queue. One possible way for loadable modules to work would be to have a built-in module LSM_ID_MODLOADER which maintains its own list of module hooks. The values returned from lsm_self_attr() would identify the this LSM and the data value would have to identify the loaded module it refers to, perhaps as "TOMOYO=XYZ" or "datastate=foobar". A flag LSM_ATTR_LOADED would indicate that the attribute needed to be processed according to loadable module attribute rules, whatever they might be. So no, it's not a show stopper. Not any more than u32 secids are a showstopper for process attributes it audit records. LSM IDs are inconvenient, and not my first choice, but I'm not going to let that get in the way of getting this code upstream. A built in module loader security module would address this issue. Getting such a module accepted upstream is not going to be trivial, but the BPF people seem to have managed it. Maybe the thing to do is rewrite TOMOYO in eBPF. If I wanted to have a loadable security module I could either take ten years or so to get a loadable module scheme upstream in addition to my module, or I could write it in eBPF and use it the next day. I don't know enough about eBPF programming to say if it has everything TOMOYO needs, but it sure looks like an easier path if it does. I hope that I have suggested viable (if not convenient) alternatives. I suppose it is possible that locking out loadable modules is one motivation behind the LSM ID scheme, but I really doubt it. And more importantly, as I've outlined above, I can't be successful in locking out loadable security modules. I don't even see it as an additional complication.

Use the LSM ID number instead of the LSM name to identify which security module's attibute data should be shown in /proc/self/attr. The security_[gs]etprocattr() functions have been changed to expect the LSM ID. The change from a string comparison to an integer comparison in these functions will provide a minor performance improvement. Signed-off-by: Casey Schaufler <casey(a)schaufler-ca.com&gt; --- fs/proc/base.c | 29 +++++++++++++++-------------- fs/proc/internal.h | 2 +- include/linux/security.h | 11 +++++------ security/security.c | 11 +++++------ 4 files changed, 26 insertions(+), 27 deletions(-) diff --git a/fs/proc/base.c b/fs/proc/base.c index 93f7e3d971e4..b2bda7d0619f 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -96,6 +96,7 @@ #include <linux/time_namespace.h> #include <linux/resctrl.h> #include <linux/cn_proc.h> +#include <uapi/linux/lsm.h> #include <trace/events/oom.h> #include "internal.h" #include "fd.h" @@ -145,10 +146,10 @@ struct pid_entry { NOD(NAME, (S_IFREG|(MODE)), \ NULL, &proc_single_file_operations, \ { .proc_show = show } ) -#define ATTR(LSM, NAME, MODE) \ +#define ATTR(LSMID, NAME, MODE) \ NOD(NAME, (S_IFREG|(MODE)), \ NULL, &proc_pid_attr_operations, \ - { .lsm = LSM }) + { .lsmid = LSMID }) /* * Count the number of hardlinks for the pid_entry table, excluding the . @@ -2727,7 +2728,7 @@ static ssize_t proc_pid_attr_read(struct file * file, char __user * buf, if (!task) return -ESRCH; - length = security_getprocattr(task, PROC_I(inode)->op.lsm, + length = security_getprocattr(task, PROC_I(inode)->op.lsmid, (char*)file->f_path.dentry->d_name.name, &p); put_task_struct(task); @@ -2785,7 +2786,7 @@ static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf, if (rv < 0) goto out_free; - rv = security_setprocattr(PROC_I(inode)->op.lsm, + rv = security_setprocattr(PROC_I(inode)->op.lsmid, file->f_path.dentry->d_name.name, page, count); mutex_unlock(&current->signal->cred_guard_mutex); @@ -2834,27 +2835,27 @@ static const struct inode_operations proc_##LSM##_attr_dir_inode_ops = { \ #ifdef CONFIG_SECURITY_SMACK static const struct pid_entry smack_attr_dir_stuff[] = { - ATTR("smack", "current", 0666), + ATTR(LSM_ID_SMACK, "current", 0666), }; LSM_DIR_OPS(smack); #endif #ifdef CONFIG_SECURITY_APPARMOR static const struct pid_entry apparmor_attr_dir_stuff[] = { - ATTR("apparmor", "current", 0666), - ATTR("apparmor", "prev", 0444), - ATTR("apparmor", "exec", 0666), + ATTR(LSM_ID_APPARMOR, "current", 0666), + ATTR(LSM_ID_APPARMOR, "prev", 0444), + ATTR(LSM_ID_APPARMOR, "exec", 0666), }; LSM_DIR_OPS(apparmor); #endif static const struct pid_entry attr_dir_stuff[] = { - ATTR(NULL, "current", 0666), - ATTR(NULL, "prev", 0444), - ATTR(NULL, "exec", 0666), - ATTR(NULL, "fscreate", 0666), - ATTR(NULL, "keycreate", 0666), - ATTR(NULL, "sockcreate", 0666), + ATTR(LSM_ID_INVALID, "current", 0666), + ATTR(LSM_ID_INVALID, "prev", 0444), + ATTR(LSM_ID_INVALID, "exec", 0666), + ATTR(LSM_ID_INVALID, "fscreate", 0666), + ATTR(LSM_ID_INVALID, "keycreate", 0666), + ATTR(LSM_ID_INVALID, "sockcreate", 0666), #ifdef CONFIG_SECURITY_SMACK DIR("smack", 0555, proc_smack_attr_dir_inode_ops, proc_smack_attr_dir_ops), diff --git a/fs/proc/internal.h b/fs/proc/internal.h index 06a80f78433d..3f6f4a7a1498 100644 --- a/fs/proc/internal.h +++ b/fs/proc/internal.h @@ -87,7 +87,7 @@ union proc_op { int (*proc_show)(struct seq_file *m, struct pid_namespace *ns, struct pid *pid, struct task_struct *task); - const char *lsm; + int lsmid; }; struct proc_inode { diff --git a/include/linux/security.h b/include/linux/security.h index abdd151fc720..c4696f14daac 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -478,10 +478,9 @@ int security_sem_semctl(struct kern_ipc_perm *sma, int cmd); int security_sem_semop(struct kern_ipc_perm *sma, struct sembuf *sops, unsigned nsops, int alter); void security_d_instantiate(struct dentry *dentry, struct inode *inode); -int security_getprocattr(struct task_struct *p, const char *lsm, char *name, +int security_getprocattr(struct task_struct *p, int lsmid, char *name, char **value); -int security_setprocattr(const char *lsm, const char *name, void *value, - size_t size); +int security_setprocattr(int lsmid, const char *name, void *value, size_t size); int security_netlink_send(struct sock *sk, struct sk_buff *skb); int security_ismaclabel(const char *name); int security_secid_to_secctx(u32 secid, char **secdata, u32 *seclen); @@ -1317,14 +1316,14 @@ static inline void security_d_instantiate(struct dentry *dentry, struct inode *inode) { } -static inline int security_getprocattr(struct task_struct *p, const char *lsm, +static inline int security_getprocattr(struct task_struct *p, int lsmid, char *name, char **value) { return -EINVAL; } -static inline int security_setprocattr(const char *lsm, char *name, - void *value, size_t size) +static inline int security_setprocattr(int lsmid, char *name, void *value, + size_t size) { return -EINVAL; } diff --git a/security/security.c b/security/security.c index 14f22d9c9d84..af62f4c1cc89 100644 --- a/security/security.c +++ b/security/security.c @@ -2075,26 +2075,25 @@ void security_d_instantiate(struct dentry *dentry, struct inode *inode) } EXPORT_SYMBOL(security_d_instantiate); -int security_getprocattr(struct task_struct *p, const char *lsm, char *name, - char **value) +int security_getprocattr(struct task_struct *p, int lsmid, char *name, + char **value) { struct security_hook_list *hp; hlist_for_each_entry(hp, &security_hook_heads.getprocattr, list) { - if (lsm != NULL && strcmp(lsm, hp->lsmid->lsm)) + if (lsmid != LSM_ID_INVALID && lsmid != hp->lsmid->id) continue; return hp->hook.getprocattr(p, name, value); } return LSM_RET_DEFAULT(getprocattr); } -int security_setprocattr(const char *lsm, const char *name, void *value, - size_t size) +int security_setprocattr(int lsmid, const char *name, void *value, size_t size) { struct security_hook_list *hp; hlist_for_each_entry(hp, &security_hook_heads.setprocattr, list) { - if (lsm != NULL && strcmp(lsm, hp->lsmid->lsm)) + if (lsmid != LSM_ID_INVALID && lsmid != hp->lsmid->id) continue; return hp->hook.setprocattr(name, value, size); } -- 2.37.3

At least linux-api(a)vger.kernel.org should be in Cc for new syscalls. You need a dedicated patch to wire this syscall with all architectures. It will help a lot dealing with merge conflicts because of other new syscalls. You can take a look at the Landlock syscall implementations: https://git.kernel.org/c/torvalds/a49f4f81cb48925e8d7cbd9e59068f516e984144 About the name, I'd suggest using a verb, something like lsm_get_self_attr. On 27/09/2022 21:53, Casey Schaufler wrote: I think this paragraph is not enough to justify a new syscall. We should highlight what is not possible (or difficult) to do with the filesystem: e.g. - usable in a sandbox which may not have access to the filesystem (but is that a good thing here?); - clearly defined ABI/format; - …? What is the goal of this syscall? How will it be used? By who? "identifies" This need to move to a dedicated "wire syscall" patch. "NULL-terminated"? I suggest using __u32 instead of unsigned int. What could be the use case for these flags? To avoid holes in this struct, you might want to use __attribute__((packed)). I'd prefer @size to not be a pointer but a value, and then only be read to get the context size. Because lazy userspace only reading the top If the ctx buffer is not big enough, lsm_module_list() already returns the enabled LSM IDs. It would be much simpler to only returns the properties of a specified LSM. The syscall could then look like this: lsm_get_self_attr(__u32 lsm_id, char *attr, size_t size, __u32 flags)

Move management of the sock->sk_security blob out of the individual security modules and into the security infrastructure. Instead of allocating the blobs from within the modules the modules tell the infrastructure how much space is required, and the space is allocated there. Acked-by: Paul Moore <paul(a)paul-moore.com&gt; Reviewed-by: Kees Cook <keescook(a)chromium.org&gt; Reviewed-by: John Johansen <john.johansen(a)canonical.com&gt; Acked-by: Stephen Smalley <stephen.smalley.work(a)gmail.com&gt; Signed-off-by: Casey Schaufler <casey(a)schaufler-ca.com&gt; --- include/linux/lsm_hooks.h | 1 + security/apparmor/include/net.h | 6 ++- security/apparmor/lsm.c | 38 ++++---------- security/apparmor/net.c | 2 +- security/security.c | 36 +++++++++++++- security/selinux/hooks.c | 82 +++++++++++++++---------------- security/selinux/include/objsec.h | 5 ++ security/selinux/netlabel.c | 23 ++++----- security/smack/smack.h | 5 ++ security/smack/smack_lsm.c | 66 ++++++++++++------------- security/smack/smack_netfilter.c | 4 +- 11 files changed, 146 insertions(+), 122 deletions(-) diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h index ded76db3f523..b266d0826278 100644 --- a/include/linux/lsm_hooks.h +++ b/include/linux/lsm_hooks.h @@ -1625,6 +1625,7 @@ struct lsm_blob_sizes { int lbs_cred; int lbs_file; int lbs_inode; + int lbs_sock; int lbs_superblock; int lbs_ipc; int lbs_msg_msg; diff --git a/security/apparmor/include/net.h b/security/apparmor/include/net.h index aadb4b29fb66..fac8999ba7a3 100644 --- a/security/apparmor/include/net.h +++ b/security/apparmor/include/net.h @@ -51,7 +51,11 @@ struct aa_sk_ctx { struct aa_label *peer; }; -#define SK_CTX(X) ((X)->sk_security) +static inline struct aa_sk_ctx *aa_sock(const struct sock *sk) +{ + return sk->sk_security + apparmor_blob_sizes.lbs_sock; +} + #define SOCK_ctx(X) SOCK_INODE(X)->i_security #define DEFINE_AUDIT_NET(NAME, OP, SK, F, T, P) \ struct lsm_network_audit NAME ## _net = { .sk = (SK), \ diff --git a/security/apparmor/lsm.c b/security/apparmor/lsm.c index 40266cc4866c..caad42a0c913 100644 --- a/security/apparmor/lsm.c +++ b/security/apparmor/lsm.c @@ -803,33 +803,15 @@ static int apparmor_task_kill(struct task_struct *target, struct kernel_siginfo return error; } -/** - * apparmor_sk_alloc_security - allocate and attach the sk_security field - */ -static int apparmor_sk_alloc_security(struct sock *sk, int family, gfp_t flags) -{ - struct aa_sk_ctx *ctx; - - ctx = kzalloc(sizeof(*ctx), flags); - if (!ctx) - return -ENOMEM; - - SK_CTX(sk) = ctx; - - return 0; -} - /** * apparmor_sk_free_security - free the sk_security field */ static void apparmor_sk_free_security(struct sock *sk) { - struct aa_sk_ctx *ctx = SK_CTX(sk); + struct aa_sk_ctx *ctx = aa_sock(sk); - SK_CTX(sk) = NULL; aa_put_label(ctx->label); aa_put_label(ctx->peer); - kfree(ctx); } /** @@ -838,8 +820,8 @@ static void apparmor_sk_free_security(struct sock *sk) static void apparmor_sk_clone_security(const struct sock *sk, struct sock *newsk) { - struct aa_sk_ctx *ctx = SK_CTX(sk); - struct aa_sk_ctx *new = SK_CTX(newsk); + struct aa_sk_ctx *ctx = aa_sock(sk); + struct aa_sk_ctx *new = aa_sock(newsk); if (new->label) aa_put_label(new->label); @@ -892,7 +874,7 @@ static int apparmor_socket_post_create(struct socket *sock, int family, label = aa_get_current_label(); if (sock->sk) { - struct aa_sk_ctx *ctx = SK_CTX(sock->sk); + struct aa_sk_ctx *ctx = aa_sock(sock->sk); aa_put_label(ctx->label); ctx->label = aa_get_label(label); @@ -1077,7 +1059,7 @@ static int apparmor_socket_shutdown(struct socket *sock, int how) */ static int apparmor_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb) { - struct aa_sk_ctx *ctx = SK_CTX(sk); + struct aa_sk_ctx *ctx = aa_sock(sk); if (!skb->secmark) return 0; @@ -1090,7 +1072,7 @@ static int apparmor_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb) static struct aa_label *sk_peer_label(struct sock *sk) { - struct aa_sk_ctx *ctx = SK_CTX(sk); + struct aa_sk_ctx *ctx = aa_sock(sk); if (ctx->peer) return ctx->peer; @@ -1174,7 +1156,7 @@ static int apparmor_socket_getpeersec_dgram(struct socket *sock, */ static void apparmor_sock_graft(struct sock *sk, struct socket *parent) { - struct aa_sk_ctx *ctx = SK_CTX(sk); + struct aa_sk_ctx *ctx = aa_sock(sk); if (!ctx->label) ctx->label = aa_get_current_label(); @@ -1184,7 +1166,7 @@ static void apparmor_sock_graft(struct sock *sk, struct socket *parent) static int apparmor_inet_conn_request(const struct sock *sk, struct sk_buff *skb, struct request_sock *req) { - struct aa_sk_ctx *ctx = SK_CTX(sk); + struct aa_sk_ctx *ctx = aa_sock(sk); if (!skb->secmark) return 0; @@ -1201,6 +1183,7 @@ struct lsm_blob_sizes apparmor_blob_sizes __lsm_ro_after_init = { .lbs_cred = sizeof(struct aa_task_ctx *), .lbs_file = sizeof(struct aa_file_ctx), .lbs_task = sizeof(struct aa_task_ctx), + .lbs_sock = sizeof(struct aa_sk_ctx), }; static struct lsm_id apparmor_lsmid __lsm_ro_after_init = { @@ -1243,7 +1226,6 @@ static struct security_hook_list apparmor_hooks[] __lsm_ro_after_init = { LSM_HOOK_INIT(getprocattr, apparmor_getprocattr), LSM_HOOK_INIT(setprocattr, apparmor_setprocattr), - LSM_HOOK_INIT(sk_alloc_security, apparmor_sk_alloc_security), LSM_HOOK_INIT(sk_free_security, apparmor_sk_free_security), LSM_HOOK_INIT(sk_clone_security, apparmor_sk_clone_security), @@ -1809,7 +1791,7 @@ static unsigned int apparmor_ip_postroute(void *priv, if (sk == NULL) return NF_ACCEPT; - ctx = SK_CTX(sk); + ctx = aa_sock(sk); if (!apparmor_secmark_check(ctx->label, OP_SENDMSG, AA_MAY_SEND, skb->secmark, sk)) return NF_ACCEPT; diff --git a/security/apparmor/net.c b/security/apparmor/net.c index 7efe4d17273d..b336e23a4467 100644 --- a/security/apparmor/net.c +++ b/security/apparmor/net.c @@ -145,7 +145,7 @@ int aa_af_perm(struct aa_label *label, const char *op, u32 request, u16 family, static int aa_label_sk_perm(struct aa_label *label, const char *op, u32 request, struct sock *sk) { - struct aa_sk_ctx *ctx = SK_CTX(sk); + struct aa_sk_ctx *ctx = aa_sock(sk); int error = 0; AA_BUG(!label); diff --git a/security/security.c b/security/security.c index b916469388b0..7a604a74716a 100644 --- a/security/security.c +++ b/security/security.c @@ -30,6 +30,7 @@ #include <linux/msg.h> #include <uapi/linux/lsm.h> #include <net/flow.h> +#include <net/sock.h> #define MAX_LSM_EVM_XATTR 2 @@ -207,6 +208,7 @@ static void __init lsm_set_blob_sizes(struct lsm_blob_sizes *needed) lsm_set_blob_size(&needed->lbs_inode, &blob_sizes.lbs_inode); lsm_set_blob_size(&needed->lbs_ipc, &blob_sizes.lbs_ipc); lsm_set_blob_size(&needed->lbs_msg_msg, &blob_sizes.lbs_msg_msg); + lsm_set_blob_size(&needed->lbs_sock, &blob_sizes.lbs_sock); lsm_set_blob_size(&needed->lbs_superblock, &blob_sizes.lbs_superblock); lsm_set_blob_size(&needed->lbs_task, &blob_sizes.lbs_task); } @@ -349,6 +351,7 @@ static void __init ordered_lsm_init(void) init_debug("inode blob size = %d\n", blob_sizes.lbs_inode); init_debug("ipc blob size = %d\n", blob_sizes.lbs_ipc); init_debug("msg_msg blob size = %d\n", blob_sizes.lbs_msg_msg); + init_debug("sock blob size = %d\n", blob_sizes.lbs_sock); init_debug("superblock blob size = %d\n", blob_sizes.lbs_superblock); init_debug("task blob size = %d\n", blob_sizes.lbs_task); @@ -678,6 +681,28 @@ static int lsm_msg_msg_alloc(struct msg_msg *mp) return 0; } +/** + * lsm_sock_alloc - allocate a composite sock blob + * @sock: the sock that needs a blob + * @priority: allocation mode + * + * Allocate the sock blob for all the modules + * + * Returns 0, or -ENOMEM if memory can't be allocated. + */ +static int lsm_sock_alloc(struct sock *sock, gfp_t priority) +{ + if (blob_sizes.lbs_sock == 0) { + sock->sk_security = NULL; + return 0; + } + + sock->sk_security = kzalloc(blob_sizes.lbs_sock, priority); + if (sock->sk_security == NULL) + return -ENOMEM; + return 0; +} + /** * lsm_early_task - during initialization allocate a composite task blob * @task: the task that needs a blob @@ -2293,12 +2318,21 @@ EXPORT_SYMBOL(security_socket_getpeersec_dgram); int security_sk_alloc(struct sock *sk, int family, gfp_t priority) { - return call_int_hook(sk_alloc_security, 0, sk, family, priority); + int rc = lsm_sock_alloc(sk, priority); + + if (unlikely(rc)) + return rc; + rc = call_int_hook(sk_alloc_security, 0, sk, family, priority); + if (unlikely(rc)) + security_sk_free(sk); + return rc; } void security_sk_free(struct sock *sk) { call_void_hook(sk_free_security, sk); + kfree(sk->sk_security); + sk->sk_security = NULL; } void security_sk_clone(const struct sock *sk, struct sock *newsk) diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index 625cc791c440..25cc17bdd33c 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -4531,7 +4531,7 @@ static int socket_sockcreate_sid(const struct task_security_struct *tsec, static int sock_has_perm(struct sock *sk, u32 perms) { - struct sk_security_struct *sksec = sk->sk_security; + struct sk_security_struct *sksec = selinux_sock(sk); struct common_audit_data ad; struct lsm_network_audit net = {0,}; @@ -4588,7 +4588,7 @@ static int selinux_socket_post_create(struct socket *sock, int family, isec->initialized = LABEL_INITIALIZED; if (sock->sk) { - sksec = sock->sk->sk_security; + sksec = selinux_sock(sock->sk); sksec->sclass = sclass; sksec->sid = sid; /* Allows detection of the first association on this socket */ @@ -4604,8 +4604,8 @@ static int selinux_socket_post_create(struct socket *sock, int family, static int selinux_socket_socketpair(struct socket *socka, struct socket *sockb) { - struct sk_security_struct *sksec_a = socka->sk->sk_security; - struct sk_security_struct *sksec_b = sockb->sk->sk_security; + struct sk_security_struct *sksec_a = selinux_sock(socka->sk); + struct sk_security_struct *sksec_b = selinux_sock(sockb->sk); sksec_a->peer_sid = sksec_b->sid; sksec_b->peer_sid = sksec_a->sid; @@ -4620,7 +4620,7 @@ static int selinux_socket_socketpair(struct socket *socka, static int selinux_socket_bind(struct socket *sock, struct sockaddr *address, int addrlen) { struct sock *sk = sock->sk; - struct sk_security_struct *sksec = sk->sk_security; + struct sk_security_struct *sksec = selinux_sock(sk); u16 family; int err; @@ -4755,7 +4755,7 @@ static int selinux_socket_connect_helper(struct socket *sock, struct sockaddr *address, int addrlen) { struct sock *sk = sock->sk; - struct sk_security_struct *sksec = sk->sk_security; + struct sk_security_struct *sksec = selinux_sock(sk); int err; err = sock_has_perm(sk, SOCKET__CONNECT); @@ -4934,9 +4934,9 @@ static int selinux_socket_unix_stream_connect(struct sock *sock, struct sock *other, struct sock *newsk) { - struct sk_security_struct *sksec_sock = sock->sk_security; - struct sk_security_struct *sksec_other = other->sk_security; - struct sk_security_struct *sksec_new = newsk->sk_security; + struct sk_security_struct *sksec_sock = selinux_sock(sock); + struct sk_security_struct *sksec_other = selinux_sock(other); + struct sk_security_struct *sksec_new = selinux_sock(newsk); struct common_audit_data ad; struct lsm_network_audit net = {0,}; int err; @@ -4968,8 +4968,8 @@ static int selinux_socket_unix_stream_connect(struct sock *sock, static int selinux_socket_unix_may_send(struct socket *sock, struct socket *other) { - struct sk_security_struct *ssec = sock->sk->sk_security; - struct sk_security_struct *osec = other->sk->sk_security; + struct sk_security_struct *ssec = selinux_sock(sock->sk); + struct sk_security_struct *osec = selinux_sock(other->sk); struct common_audit_data ad; struct lsm_network_audit net = {0,}; @@ -5011,7 +5011,7 @@ static int selinux_sock_rcv_skb_compat(struct sock *sk, struct sk_buff *skb, u16 family) { int err = 0; - struct sk_security_struct *sksec = sk->sk_security; + struct sk_security_struct *sksec = selinux_sock(sk); u32 sk_sid = sksec->sid; struct common_audit_data ad; struct lsm_network_audit net = {0,}; @@ -5044,7 +5044,7 @@ static int selinux_sock_rcv_skb_compat(struct sock *sk, struct sk_buff *skb, static int selinux_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb) { int err; - struct sk_security_struct *sksec = sk->sk_security; + struct sk_security_struct *sksec = selinux_sock(sk); u16 family = sk->sk_family; u32 sk_sid = sksec->sid; struct common_audit_data ad; @@ -5112,13 +5112,15 @@ static int selinux_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb) return err; } -static int selinux_socket_getpeersec_stream(struct socket *sock, char __user *optval, - int __user *optlen, unsigned len) +static int selinux_socket_getpeersec_stream(struct socket *sock, + char __user *optval, + int __user *optlen, + unsigned int len) { int err = 0; char *scontext; u32 scontext_len; - struct sk_security_struct *sksec = sock->sk->sk_security; + struct sk_security_struct *sksec = selinux_sock(sock->sk); u32 peer_sid = SECSID_NULL; if (sksec->sclass == SECCLASS_UNIX_STREAM_SOCKET || @@ -5178,34 +5180,27 @@ static int selinux_socket_getpeersec_dgram(struct socket *sock, struct sk_buff * static int selinux_sk_alloc_security(struct sock *sk, int family, gfp_t priority) { - struct sk_security_struct *sksec; - - sksec = kzalloc(sizeof(*sksec), priority); - if (!sksec) - return -ENOMEM; + struct sk_security_struct *sksec = selinux_sock(sk); sksec->peer_sid = SECINITSID_UNLABELED; sksec->sid = SECINITSID_UNLABELED; sksec->sclass = SECCLASS_SOCKET; selinux_netlbl_sk_security_reset(sksec); - sk->sk_security = sksec; return 0; } static void selinux_sk_free_security(struct sock *sk) { - struct sk_security_struct *sksec = sk->sk_security; + struct sk_security_struct *sksec = selinux_sock(sk); - sk->sk_security = NULL; selinux_netlbl_sk_security_free(sksec); - kfree(sksec); } static void selinux_sk_clone_security(const struct sock *sk, struct sock *newsk) { - struct sk_security_struct *sksec = sk->sk_security; - struct sk_security_struct *newsksec = newsk->sk_security; + struct sk_security_struct *sksec = selinux_sock(sk); + struct sk_security_struct *newsksec = selinux_sock(newsk); newsksec->sid = sksec->sid; newsksec->peer_sid = sksec->peer_sid; @@ -5219,7 +5214,7 @@ static void selinux_sk_getsecid(struct sock *sk, u32 *secid) if (!sk) *secid = SECINITSID_ANY_SOCKET; else { - struct sk_security_struct *sksec = sk->sk_security; + struct sk_security_struct *sksec = selinux_sock(sk); *secid = sksec->sid; } @@ -5229,7 +5224,7 @@ static void selinux_sock_graft(struct sock *sk, struct socket *parent) { struct inode_security_struct *isec = inode_security_novalidate(SOCK_INODE(parent)); - struct sk_security_struct *sksec = sk->sk_security; + struct sk_security_struct *sksec = selinux_sock(sk); if (sk->sk_family == PF_INET || sk->sk_family == PF_INET6 || sk->sk_family == PF_UNIX) @@ -5246,7 +5241,7 @@ static int selinux_sctp_process_new_assoc(struct sctp_association *asoc, { struct sock *sk = asoc->base.sk; u16 family = sk->sk_family; - struct sk_security_struct *sksec = sk->sk_security; + struct sk_security_struct *sksec = selinux_sock(sk); struct common_audit_data ad; struct lsm_network_audit net = {0,}; int err; @@ -5304,7 +5299,7 @@ static int selinux_sctp_process_new_assoc(struct sctp_association *asoc, static int selinux_sctp_assoc_request(struct sctp_association *asoc, struct sk_buff *skb) { - struct sk_security_struct *sksec = asoc->base.sk->sk_security; + struct sk_security_struct *sksec = selinux_sock(asoc->base.sk); u32 conn_sid; int err; @@ -5337,7 +5332,7 @@ static int selinux_sctp_assoc_request(struct sctp_association *asoc, static int selinux_sctp_assoc_established(struct sctp_association *asoc, struct sk_buff *skb) { - struct sk_security_struct *sksec = asoc->base.sk->sk_security; + struct sk_security_struct *sksec = selinux_sock(asoc->base.sk); if (!selinux_policycap_extsockclass()) return 0; @@ -5436,8 +5431,8 @@ static int selinux_sctp_bind_connect(struct sock *sk, int optname, static void selinux_sctp_sk_clone(struct sctp_association *asoc, struct sock *sk, struct sock *newsk) { - struct sk_security_struct *sksec = sk->sk_security; - struct sk_security_struct *newsksec = newsk->sk_security; + struct sk_security_struct *sksec = selinux_sock(sk); + struct sk_security_struct *newsksec = selinux_sock(newsk); /* If policy does not support SECCLASS_SCTP_SOCKET then call * the non-sctp clone version. @@ -5454,7 +5449,7 @@ static void selinux_sctp_sk_clone(struct sctp_association *asoc, struct sock *sk static int selinux_inet_conn_request(const struct sock *sk, struct sk_buff *skb, struct request_sock *req) { - struct sk_security_struct *sksec = sk->sk_security; + struct sk_security_struct *sksec = selinux_sock(sk); int err; u16 family = req->rsk_ops->family; u32 connsid; @@ -5475,7 +5470,7 @@ static int selinux_inet_conn_request(const struct sock *sk, struct sk_buff *skb, static void selinux_inet_csk_clone(struct sock *newsk, const struct request_sock *req) { - struct sk_security_struct *newsksec = newsk->sk_security; + struct sk_security_struct *newsksec = selinux_sock(newsk); newsksec->sid = req->secid; newsksec->peer_sid = req->peer_secid; @@ -5492,7 +5487,7 @@ static void selinux_inet_csk_clone(struct sock *newsk, static void selinux_inet_conn_established(struct sock *sk, struct sk_buff *skb) { u16 family = sk->sk_family; - struct sk_security_struct *sksec = sk->sk_security; + struct sk_security_struct *sksec = selinux_sock(sk); /* handle mapped IPv4 packets arriving via IPv6 sockets */ if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP)) @@ -5576,7 +5571,7 @@ static int selinux_tun_dev_attach_queue(void *security) static int selinux_tun_dev_attach(struct sock *sk, void *security) { struct tun_security_struct *tunsec = security; - struct sk_security_struct *sksec = sk->sk_security; + struct sk_security_struct *sksec = selinux_sock(sk); /* we don't currently perform any NetLabel based labeling here and it * isn't clear that we would want to do so anyway; while we could apply @@ -5705,7 +5700,7 @@ static unsigned int selinux_ip_output(void *priv, struct sk_buff *skb, return NF_ACCEPT; /* standard practice, label using the parent socket */ - sksec = sk->sk_security; + sksec = selinux_sock(sk); sid = sksec->sid; } else sid = SECINITSID_KERNEL; @@ -5728,7 +5723,7 @@ static unsigned int selinux_ip_postroute_compat(struct sk_buff *skb, sk = skb_to_full_sk(skb); if (sk == NULL) return NF_ACCEPT; - sksec = sk->sk_security; + sksec = selinux_sock(sk); ad.type = LSM_AUDIT_DATA_NET; ad.u.net = &net; @@ -5821,7 +5816,7 @@ static unsigned int selinux_ip_postroute(void *priv, u32 skb_sid; struct sk_security_struct *sksec; - sksec = sk->sk_security; + sksec = selinux_sock(sk); if (selinux_skb_peerlbl_sid(skb, family, &skb_sid)) return NF_DROP; /* At this point, if the returned skb peerlbl is SECSID_NULL @@ -5850,7 +5845,7 @@ static unsigned int selinux_ip_postroute(void *priv, } else { /* Locally generated packet, fetch the security label from the * associated socket. */ - struct sk_security_struct *sksec = sk->sk_security; + struct sk_security_struct *sksec = selinux_sock(sk); peer_sid = sksec->sid; secmark_perm = PACKET__SEND; } @@ -5899,7 +5894,7 @@ static int selinux_netlink_send(struct sock *sk, struct sk_buff *skb) unsigned int data_len = skb->len; unsigned char *data = skb->data; struct nlmsghdr *nlh; - struct sk_security_struct *sksec = sk->sk_security; + struct sk_security_struct *sksec = selinux_sock(sk); u16 sclass = sksec->sclass; u32 perm; @@ -6898,6 +6893,7 @@ struct lsm_blob_sizes selinux_blob_sizes __lsm_ro_after_init = { .lbs_inode = sizeof(struct inode_security_struct), .lbs_ipc = sizeof(struct ipc_security_struct), .lbs_msg_msg = sizeof(struct msg_security_struct), + .lbs_sock = sizeof(struct sk_security_struct), .lbs_superblock = sizeof(struct superblock_security_struct), }; diff --git a/security/selinux/include/objsec.h b/security/selinux/include/objsec.h index 2953132408bf..007d1ae7ee27 100644 --- a/security/selinux/include/objsec.h +++ b/security/selinux/include/objsec.h @@ -194,4 +194,9 @@ static inline struct superblock_security_struct *selinux_superblock( return superblock->s_security + selinux_blob_sizes.lbs_superblock; } +static inline struct sk_security_struct *selinux_sock(const struct sock *sock) +{ + return sock->sk_security + selinux_blob_sizes.lbs_sock; +} + #endif /* _SELINUX_OBJSEC_H_ */ diff --git a/security/selinux/netlabel.c b/security/selinux/netlabel.c index 1321f15799e2..800ab4b4239e 100644 --- a/security/selinux/netlabel.c +++ b/security/selinux/netlabel.c @@ -17,6 +17,7 @@ #include <linux/gfp.h> #include <linux/ip.h> #include <linux/ipv6.h> +#include <linux/lsm_hooks.h> #include <net/sock.h> #include <net/netlabel.h> #include <net/ip.h> @@ -68,7 +69,7 @@ static int selinux_netlbl_sidlookup_cached(struct sk_buff *skb, static struct netlbl_lsm_secattr *selinux_netlbl_sock_genattr(struct sock *sk) { int rc; - struct sk_security_struct *sksec = sk->sk_security; + struct sk_security_struct *sksec = selinux_sock(sk); struct netlbl_lsm_secattr *secattr; if (sksec->nlbl_secattr != NULL) @@ -101,7 +102,7 @@ static struct netlbl_lsm_secattr *selinux_netlbl_sock_getattr( const struct sock *sk, u32 sid) { - struct sk_security_struct *sksec = sk->sk_security; + struct sk_security_struct *sksec = selinux_sock(sk); struct netlbl_lsm_secattr *secattr = sksec->nlbl_secattr; if (secattr == NULL) @@ -236,7 +237,7 @@ int selinux_netlbl_skbuff_setsid(struct sk_buff *skb, * being labeled by it's parent socket, if it is just exit */ sk = skb_to_full_sk(skb); if (sk != NULL) { - struct sk_security_struct *sksec = sk->sk_security; + struct sk_security_struct *sksec = selinux_sock(sk); if (sksec->nlbl_state != NLBL_REQSKB) return 0; @@ -274,7 +275,7 @@ int selinux_netlbl_sctp_assoc_request(struct sctp_association *asoc, { int rc; struct netlbl_lsm_secattr secattr; - struct sk_security_struct *sksec = asoc->base.sk->sk_security; + struct sk_security_struct *sksec = selinux_sock(asoc->base.sk); struct sockaddr_in addr4; struct sockaddr_in6 addr6; @@ -355,7 +356,7 @@ int selinux_netlbl_inet_conn_request(struct request_sock *req, u16 family) */ void selinux_netlbl_inet_csk_clone(struct sock *sk, u16 family) { - struct sk_security_struct *sksec = sk->sk_security; + struct sk_security_struct *sksec = selinux_sock(sk); if (family == PF_INET) sksec->nlbl_state = NLBL_LABELED; @@ -373,8 +374,8 @@ void selinux_netlbl_inet_csk_clone(struct sock *sk, u16 family) */ void selinux_netlbl_sctp_sk_clone(struct sock *sk, struct sock *newsk) { - struct sk_security_struct *sksec = sk->sk_security; - struct sk_security_struct *newsksec = newsk->sk_security; + struct sk_security_struct *sksec = selinux_sock(sk); + struct sk_security_struct *newsksec = selinux_sock(newsk); newsksec->nlbl_state = sksec->nlbl_state; } @@ -392,7 +393,7 @@ void selinux_netlbl_sctp_sk_clone(struct sock *sk, struct sock *newsk) int selinux_netlbl_socket_post_create(struct sock *sk, u16 family) { int rc; - struct sk_security_struct *sksec = sk->sk_security; + struct sk_security_struct *sksec = selinux_sock(sk); struct netlbl_lsm_secattr *secattr; if (family != PF_INET && family != PF_INET6) @@ -507,7 +508,7 @@ int selinux_netlbl_socket_setsockopt(struct socket *sock, { int rc = 0; struct sock *sk = sock->sk; - struct sk_security_struct *sksec = sk->sk_security; + struct sk_security_struct *sksec = selinux_sock(sk); struct netlbl_lsm_secattr secattr; if (selinux_netlbl_option(level, optname) && @@ -545,7 +546,7 @@ static int selinux_netlbl_socket_connect_helper(struct sock *sk, struct sockaddr *addr) { int rc; - struct sk_security_struct *sksec = sk->sk_security; + struct sk_security_struct *sksec = selinux_sock(sk); struct netlbl_lsm_secattr *secattr; /* connected sockets are allowed to disconnect when the address family @@ -584,7 +585,7 @@ static int selinux_netlbl_socket_connect_helper(struct sock *sk, int selinux_netlbl_socket_connect_locked(struct sock *sk, struct sockaddr *addr) { - struct sk_security_struct *sksec = sk->sk_security; + struct sk_security_struct *sksec = selinux_sock(sk); if (sksec->nlbl_state != NLBL_REQSKB && sksec->nlbl_state != NLBL_CONNLABELED) diff --git a/security/smack/smack.h b/security/smack/smack.h index fc837dcebf96..ef9d0b7b1954 100644 --- a/security/smack/smack.h +++ b/security/smack/smack.h @@ -363,6 +363,11 @@ static inline struct superblock_smack *smack_superblock( return superblock->s_security + smack_blob_sizes.lbs_superblock; } +static inline struct socket_smack *smack_sock(const struct sock *sock) +{ + return sock->sk_security + smack_blob_sizes.lbs_sock; +} + /* * Is the directory transmuting? */ diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c index e79640a6bfd7..c399ed799ceb 100644 --- a/security/smack/smack_lsm.c +++ b/security/smack/smack_lsm.c @@ -1429,7 +1429,7 @@ static int smack_inode_getsecurity(struct user_namespace *mnt_userns, if (sock == NULL || sock->sk == NULL) return -EOPNOTSUPP; - ssp = sock->sk->sk_security; + ssp = smack_sock(sock->sk); if (strcmp(name, XATTR_SMACK_IPIN) == 0) isp = ssp->smk_in; @@ -1812,7 +1812,7 @@ static int smack_file_receive(struct file *file) if (inode->i_sb->s_magic == SOCKFS_MAGIC) { sock = SOCKET_I(inode); - ssp = sock->sk->sk_security; + ssp = smack_sock(sock->sk); tsp = smack_cred(current_cred()); /* * If the receiving process can't write to the @@ -2232,11 +2232,7 @@ static void smack_task_to_inode(struct task_struct *p, struct inode *inode) static int smack_sk_alloc_security(struct sock *sk, int family, gfp_t gfp_flags) { struct smack_known *skp = smk_of_current(); - struct socket_smack *ssp; - - ssp = kzalloc(sizeof(struct socket_smack), gfp_flags); - if (ssp == NULL) - return -ENOMEM; + struct socket_smack *ssp = smack_sock(sk); /* * Sockets created by kernel threads receive web label. @@ -2250,11 +2246,10 @@ static int smack_sk_alloc_security(struct sock *sk, int family, gfp_t gfp_flags) } ssp->smk_packet = NULL; - sk->sk_security = ssp; - return 0; } +#ifdef SMACK_IPV6_PORT_LABELING /** * smack_sk_free_security - Free a socket blob * @sk: the socket @@ -2263,7 +2258,6 @@ static int smack_sk_alloc_security(struct sock *sk, int family, gfp_t gfp_flags) */ static void smack_sk_free_security(struct sock *sk) { -#ifdef SMACK_IPV6_PORT_LABELING struct smk_port_label *spp; if (sk->sk_family == PF_INET6) { @@ -2276,9 +2270,8 @@ static void smack_sk_free_security(struct sock *sk) } rcu_read_unlock(); } -#endif - kfree(sk->sk_security); } +#endif /** * smack_ipv4host_label - check host based restrictions @@ -2391,7 +2384,7 @@ static struct smack_known *smack_ipv6host_label(struct sockaddr_in6 *sip) */ static int smack_netlbl_add(struct sock *sk) { - struct socket_smack *ssp = sk->sk_security; + struct socket_smack *ssp = smack_sock(sk); struct smack_known *skp = ssp->smk_out; int rc; @@ -2423,7 +2416,7 @@ static int smack_netlbl_add(struct sock *sk) */ static void smack_netlbl_delete(struct sock *sk) { - struct socket_smack *ssp = sk->sk_security; + struct socket_smack *ssp = smack_sock(sk); /* * Take the label off the socket if one is set. @@ -2455,7 +2448,7 @@ static int smk_ipv4_check(struct sock *sk, struct sockaddr_in *sap) struct smack_known *skp; int rc = 0; struct smack_known *hkp; - struct socket_smack *ssp = sk->sk_security; + struct socket_smack *ssp = smack_sock(sk); struct smk_audit_info ad; rcu_read_lock(); @@ -2528,7 +2521,7 @@ static void smk_ipv6_port_label(struct socket *sock, struct sockaddr *address) { struct sock *sk = sock->sk; struct sockaddr_in6 *addr6; - struct socket_smack *ssp = sock->sk->sk_security; + struct socket_smack *ssp = smack_sock(sock->sk); struct smk_port_label *spp; unsigned short port = 0; @@ -2616,7 +2609,7 @@ static int smk_ipv6_port_check(struct sock *sk, struct sockaddr_in6 *address, int act) { struct smk_port_label *spp; - struct socket_smack *ssp = sk->sk_security; + struct socket_smack *ssp = smack_sock(sk); struct smack_known *skp = NULL; unsigned short port; struct smack_known *object; @@ -2710,7 +2703,7 @@ static int smack_inode_setsecurity(struct inode *inode, const char *name, if (sock == NULL || sock->sk == NULL) return -EOPNOTSUPP; - ssp = sock->sk->sk_security; + ssp = smack_sock(sock->sk); if (strcmp(name, XATTR_SMACK_IPIN) == 0) ssp->smk_in = skp; @@ -2758,7 +2751,7 @@ static int smack_socket_post_create(struct socket *sock, int family, * Sockets created by kernel threads receive web label. */ if (unlikely(current->flags & PF_KTHREAD)) { - ssp = sock->sk->sk_security; + ssp = smack_sock(sock->sk); ssp->smk_in = &smack_known_web; ssp->smk_out = &smack_known_web; } @@ -2783,8 +2776,8 @@ static int smack_socket_post_create(struct socket *sock, int family, static int smack_socket_socketpair(struct socket *socka, struct socket *sockb) { - struct socket_smack *asp = socka->sk->sk_security; - struct socket_smack *bsp = sockb->sk->sk_security; + struct socket_smack *asp = smack_sock(socka->sk); + struct socket_smack *bsp = smack_sock(sockb->sk); asp->smk_packet = bsp->smk_out; bsp->smk_packet = asp->smk_out; @@ -2847,7 +2840,7 @@ static int smack_socket_connect(struct socket *sock, struct sockaddr *sap, if (__is_defined(SMACK_IPV6_SECMARK_LABELING)) rsp = smack_ipv6host_label(sip); if (rsp != NULL) { - struct socket_smack *ssp = sock->sk->sk_security; + struct socket_smack *ssp = smack_sock(sock->sk); rc = smk_ipv6_check(ssp->smk_out, rsp, sip, SMK_CONNECTING); @@ -3578,9 +3571,9 @@ static int smack_unix_stream_connect(struct sock *sock, { struct smack_known *skp; struct smack_known *okp; - struct socket_smack *ssp = sock->sk_security; - struct socket_smack *osp = other->sk_security; - struct socket_smack *nsp = newsk->sk_security; + struct socket_smack *ssp = smack_sock(sock); + struct socket_smack *osp = smack_sock(other); + struct socket_smack *nsp = smack_sock(newsk); struct smk_audit_info ad; int rc = 0; #ifdef CONFIG_AUDIT @@ -3626,8 +3619,8 @@ static int smack_unix_stream_connect(struct sock *sock, */ static int smack_unix_may_send(struct socket *sock, struct socket *other) { - struct socket_smack *ssp = sock->sk->sk_security; - struct socket_smack *osp = other->sk->sk_security; + struct socket_smack *ssp = smack_sock(sock->sk); + struct socket_smack *osp = smack_sock(other->sk); struct smk_audit_info ad; int rc; @@ -3664,7 +3657,7 @@ static int smack_socket_sendmsg(struct socket *sock, struct msghdr *msg, struct sockaddr_in6 *sap = (struct sockaddr_in6 *) msg->msg_name; #endif #ifdef SMACK_IPV6_SECMARK_LABELING - struct socket_smack *ssp = sock->sk->sk_security; + struct socket_smack *ssp = smack_sock(sock->sk); struct smack_known *rsp; #endif int rc = 0; @@ -3876,7 +3869,7 @@ static struct smack_known *smack_from_netlbl(const struct sock *sk, u16 family, netlbl_secattr_init(&secattr); if (sk) - ssp = sk->sk_security; + ssp = smack_sock(sk); if (netlbl_skbuff_getattr(skb, family, &secattr) == 0) { skp = smack_from_secattr(&secattr, ssp); @@ -3898,7 +3891,7 @@ static struct smack_known *smack_from_netlbl(const struct sock *sk, u16 family, */ static int smack_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb) { - struct socket_smack *ssp = sk->sk_security; + struct socket_smack *ssp = smack_sock(sk); struct smack_known *skp = NULL; int rc = 0; struct smk_audit_info ad; @@ -4002,7 +3995,7 @@ static int smack_socket_getpeersec_stream(struct socket *sock, int slen = 1; int rc = 0; - ssp = sock->sk->sk_security; + ssp = smack_sock(sock->sk); if (ssp->smk_packet != NULL) { rcp = ssp->smk_packet->smk_known; slen = strlen(rcp) + 1; @@ -4051,7 +4044,7 @@ static int smack_socket_getpeersec_dgram(struct socket *sock, switch (family) { case PF_UNIX: - ssp = sock->sk->sk_security; + ssp = smack_sock(sock->sk); s = ssp->smk_out->smk_secid; break; case PF_INET: @@ -4100,7 +4093,7 @@ static void smack_sock_graft(struct sock *sk, struct socket *parent) (sk->sk_family != PF_INET && sk->sk_family != PF_INET6)) return; - ssp = sk->sk_security; + ssp = smack_sock(sk); ssp->smk_in = skp; ssp->smk_out = skp; /* cssp->smk_packet is already set in smack_inet_csk_clone() */ @@ -4120,7 +4113,7 @@ static int smack_inet_conn_request(const struct sock *sk, struct sk_buff *skb, { u16 family = sk->sk_family; struct smack_known *skp; - struct socket_smack *ssp = sk->sk_security; + struct socket_smack *ssp = smack_sock(sk); struct sockaddr_in addr; struct iphdr *hdr; struct smack_known *hskp; @@ -4206,7 +4199,7 @@ static int smack_inet_conn_request(const struct sock *sk, struct sk_buff *skb, static void smack_inet_csk_clone(struct sock *sk, const struct request_sock *req) { - struct socket_smack *ssp = sk->sk_security; + struct socket_smack *ssp = smack_sock(sk); struct smack_known *skp; if (req->peer_secid != 0) { @@ -4772,6 +4765,7 @@ struct lsm_blob_sizes smack_blob_sizes __lsm_ro_after_init = { .lbs_inode = sizeof(struct inode_smack), .lbs_ipc = sizeof(struct smack_known *), .lbs_msg_msg = sizeof(struct smack_known *), + .lbs_sock = sizeof(struct socket_smack), .lbs_superblock = sizeof(struct superblock_smack), }; @@ -4888,7 +4882,9 @@ static struct security_hook_list smack_hooks[] __lsm_ro_after_init = { LSM_HOOK_INIT(socket_getpeersec_stream, smack_socket_getpeersec_stream), LSM_HOOK_INIT(socket_getpeersec_dgram, smack_socket_getpeersec_dgram), LSM_HOOK_INIT(sk_alloc_security, smack_sk_alloc_security), +#ifdef SMACK_IPV6_PORT_LABELING LSM_HOOK_INIT(sk_free_security, smack_sk_free_security), +#endif LSM_HOOK_INIT(sock_graft, smack_sock_graft), LSM_HOOK_INIT(inet_conn_request, smack_inet_conn_request), LSM_HOOK_INIT(inet_csk_clone, smack_inet_csk_clone), diff --git a/security/smack/smack_netfilter.c b/security/smack/smack_netfilter.c index b945c1d3a743..bad71b7e648d 100644 --- a/security/smack/smack_netfilter.c +++ b/security/smack/smack_netfilter.c @@ -26,8 +26,8 @@ static unsigned int smack_ip_output(void *priv, struct socket_smack *ssp; struct smack_known *skp; - if (sk && sk->sk_security) { - ssp = sk->sk_security; + if (sk) { + ssp = smack_sock(sk); skp = ssp->smk_out; skb->secmark = skp->smk_secid; } -- 2.37.3

When more than one security module is exporting data to audit and networking sub-systems a single 32 bit integer is no longer sufficient to represent the data. Add a structure to be used instead. The lsmblob structure is currently an array of u32 "secids". There is an entry for each of the security modules built into the system that would use secids if active. The system assigns the module a "slot" when it registers hooks. If modules are compiled in but not registered there will be unused slots. The slot number is added to the lsm_id structure. The audit rules data is expanded to use an array of security module data rather than a single instance. A new structure audit_lsm_rules is defined to avoid the confusion which commonly accompanies the use of void ** parameters. Signed-off-by: Casey Schaufler <casey(a)schaufler-ca.com&gt; --- include/linux/audit.h | 9 ++++- include/linux/lsm_hooks.h | 1 + include/linux/security.h | 75 +++++++++++++++++++++++++++++++++--- kernel/auditfilter.c | 23 +++++------ kernel/auditsc.c | 17 ++++---- security/apparmor/lsm.c | 1 + security/bpf/hooks.c | 1 + security/commoncap.c | 1 + security/landlock/setup.c | 1 + security/loadpin/loadpin.c | 1 + security/lockdown/lockdown.c | 1 + security/safesetid/lsm.c | 1 + security/security.c | 70 ++++++++++++++++++++++++++++++--- security/selinux/hooks.c | 1 + security/smack/smack_lsm.c | 1 + security/tomoyo/tomoyo.c | 1 + security/yama/yama_lsm.c | 1 + 17 files changed, 171 insertions(+), 35 deletions(-) diff --git a/include/linux/audit.h b/include/linux/audit.h index 3608992848d3..edb919722448 100644 --- a/include/linux/audit.h +++ b/include/linux/audit.h @@ -11,6 +11,7 @@ #include <linux/sched.h> #include <linux/ptrace.h> +#include <linux/security.h> #include <linux/audit_arch.h> #include <uapi/linux/audit.h> #include <uapi/linux/netfilter/nf_tables.h> @@ -59,6 +60,10 @@ struct audit_krule { /* Flag to indicate legacy AUDIT_LOGINUID unset usage */ #define AUDIT_LOGINUID_LEGACY 0x1 +struct audit_lsm_rules { + void *rule[LSMBLOB_ENTRIES]; +}; + struct audit_field { u32 type; union { @@ -66,8 +71,8 @@ struct audit_field { kuid_t uid; kgid_t gid; struct { - char *lsm_str; - void *lsm_rule; + char *lsm_str; + struct audit_lsm_rules lsm_rules; }; }; u32 op; diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h index b266d0826278..db251a51d4cb 100644 --- a/include/linux/lsm_hooks.h +++ b/include/linux/lsm_hooks.h @@ -1605,6 +1605,7 @@ struct lsm_id { const char *lsm; /* Name of the LSM */ int id; /* LSM ID */ int features; /* Set of LSM features */ + int slot; /* Slot in lsmblob if allocated */ }; /* diff --git a/include/linux/security.h b/include/linux/security.h index fe3273a6498f..c1f8b33e7c27 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -39,6 +39,7 @@ struct kernel_siginfo; struct sembuf; struct kern_ipc_perm; struct audit_context; +struct audit_lsm_rules; struct super_block; struct inode; struct dentry; @@ -153,6 +154,66 @@ extern const char *const lockdown_reasons[LOCKDOWN_CONFIDENTIALITY_MAX+1]; extern int lsm_id; extern struct lsm_id *lsm_idlist[]; +/* + * Data exported by the security modules + * + * Any LSM that provides secid or secctx based hooks must be included. + */ +#define LSMBLOB_ENTRIES ( \ + (IS_ENABLED(CONFIG_SECURITY_SELINUX) ? 1 : 0) + \ + (IS_ENABLED(CONFIG_SECURITY_SMACK) ? 1 : 0) + \ + (IS_ENABLED(CONFIG_SECURITY_APPARMOR) ? 1 : 0) + \ + (IS_ENABLED(CONFIG_BPF_LSM) ? 1 : 0)) + +struct lsmblob { + u32 secid[LSMBLOB_ENTRIES]; +}; + +#define LSMBLOB_INVALID -1 /* Not a valid LSM slot number */ +#define LSMBLOB_NEEDED -2 /* Slot requested on initialization */ +#define LSMBLOB_NOT_NEEDED -3 /* Slot not requested */ + +/** + * lsmblob_init - initialize a lsmblob structure + * @blob: Pointer to the data to initialize + * @secid: The initial secid value + * + * Set all secid for all modules to the specified value. + */ +static inline void lsmblob_init(struct lsmblob *blob, u32 secid) +{ + int i; + + for (i = 0; i < LSMBLOB_ENTRIES; i++) + blob->secid[i] = secid; +} + +/** + * lsmblob_is_set - report if there is a value in the lsmblob + * @blob: Pointer to the exported LSM data + * + * Returns true if there is a secid set, false otherwise + */ +static inline bool lsmblob_is_set(struct lsmblob *blob) +{ + const struct lsmblob empty = {}; + + return !!memcmp(blob, &empty, sizeof(*blob)); +} + +/** + * lsmblob_equal - report if the two lsmblob's are equal + * @bloba: Pointer to one LSM data + * @blobb: Pointer to the other LSM data + * + * Returns true if all entries in the two are equal, false otherwise + */ +static inline bool lsmblob_equal(const struct lsmblob *bloba, + const struct lsmblob *blobb) +{ + return !memcmp(bloba, blobb, sizeof(*bloba)); +} + /* These functions are in security/commoncap.c */ extern int cap_capable(const struct cred *cred, struct user_namespace *ns, int cap, unsigned int opts); @@ -1914,15 +1975,17 @@ static inline int security_key_getsecurity(struct key *key, char **_buffer) #ifdef CONFIG_AUDIT #ifdef CONFIG_SECURITY -int security_audit_rule_init(u32 field, u32 op, char *rulestr, void **lsmrule); +int security_audit_rule_init(u32 field, u32 op, char *rulestr, + struct audit_lsm_rules *lsmrules); int security_audit_rule_known(struct audit_krule *krule); -int security_audit_rule_match(u32 secid, u32 field, u32 op, void *lsmrule); -void security_audit_rule_free(void *lsmrule); +int security_audit_rule_match(u32 secid, u32 field, u32 op, + struct audit_lsm_rules *lsmrules); +void security_audit_rule_free(struct audit_lsm_rules *lsmrules); #else static inline int security_audit_rule_init(u32 field, u32 op, char *rulestr, - void **lsmrule) + struct audit_lsm_rules *lsmrules) { return 0; } @@ -1933,12 +1996,12 @@ static inline int security_audit_rule_known(struct audit_krule *krule) } static inline int security_audit_rule_match(u32 secid, u32 field, u32 op, - void *lsmrule) + struct audit_lsm_rules *lsmrules) { return 0; } -static inline void security_audit_rule_free(void *lsmrule) +static inline void security_audit_rule_free(struct audit_lsm_rules *lsmrules) { } #endif /* CONFIG_SECURITY */ diff --git a/kernel/auditfilter.c b/kernel/auditfilter.c index 42d99896e7a6..de75bd6ad866 100644 --- a/kernel/auditfilter.c +++ b/kernel/auditfilter.c @@ -76,7 +76,7 @@ static void audit_free_lsm_field(struct audit_field *f) case AUDIT_OBJ_LEV_LOW: case AUDIT_OBJ_LEV_HIGH: kfree(f->lsm_str); - security_audit_rule_free(f->lsm_rule); + security_audit_rule_free(&f->lsm_rules); } } @@ -529,7 +529,7 @@ static struct audit_entry *audit_data_to_entry(struct audit_rule_data *data, entry->rule.buflen += f_val; f->lsm_str = str; err = security_audit_rule_init(f->type, f->op, str, - (void **)&f->lsm_rule); + &f->lsm_rules); /* Keep currently invalid fields around in case they * become valid after a policy reload. */ if (err == -EINVAL) { @@ -782,7 +782,7 @@ static int audit_compare_rule(struct audit_krule *a, struct audit_krule *b) return 0; } -/* Duplicate LSM field information. The lsm_rule is opaque, so must be +/* Duplicate LSM field information. The lsm_rules is opaque, so must be * re-initialized. */ static inline int audit_dupe_lsm_field(struct audit_field *df, struct audit_field *sf) @@ -796,9 +796,9 @@ static inline int audit_dupe_lsm_field(struct audit_field *df, return -ENOMEM; df->lsm_str = lsm_str; - /* our own (refreshed) copy of lsm_rule */ + /* our own (refreshed) copy of lsm_rules */ ret = security_audit_rule_init(df->type, df->op, df->lsm_str, - (void **)&df->lsm_rule); + &df->lsm_rules); /* Keep currently invalid fields around in case they * become valid after a policy reload. */ if (ret == -EINVAL) { @@ -850,7 +850,7 @@ struct audit_entry *audit_dupe_rule(struct audit_krule *old) new->tree = old->tree; memcpy(new->fields, old->fields, sizeof(struct audit_field) * fcount); - /* deep copy this information, updating the lsm_rule fields, because + /* deep copy this information, updating the lsm_rules fields, because * the originals will all be freed when the old rule is freed. */ for (i = 0; i < fcount; i++) { switch (new->fields[i].type) { @@ -1367,10 +1367,11 @@ int audit_filter(int msgtype, unsigned int listtype) case AUDIT_SUBJ_TYPE: case AUDIT_SUBJ_SEN: case AUDIT_SUBJ_CLR: - if (f->lsm_rule) { + if (f->lsm_str) { security_current_getsecid_subj(&sid); result = security_audit_rule_match(sid, - f->type, f->op, f->lsm_rule); + f->type, f->op, + &f->lsm_rules); } break; case AUDIT_EXE: @@ -1397,7 +1398,7 @@ int audit_filter(int msgtype, unsigned int listtype) return ret; } -static int update_lsm_rule(struct audit_krule *r) +static int update_lsm_rules(struct audit_krule *r) { struct audit_entry *entry = container_of(r, struct audit_entry, rule); struct audit_entry *nentry; @@ -1429,7 +1430,7 @@ static int update_lsm_rule(struct audit_krule *r) return err; } -/* This function will re-initialize the lsm_rule field of all applicable rules. +/* This function will re-initialize the lsm_rules field of all applicable rules. * It will traverse the filter lists serarching for rules that contain LSM * specific filter fields. When such a rule is found, it is copied, the * LSM field is re-initialized, and the old rule is replaced with the @@ -1444,7 +1445,7 @@ int audit_update_lsm_rules(void) for (i = 0; i < AUDIT_NR_FILTERS; i++) { list_for_each_entry_safe(r, n, &audit_rules_list[i], list) { - int res = update_lsm_rule(r); + int res = update_lsm_rules(r); if (!err) err = res; } diff --git a/kernel/auditsc.c b/kernel/auditsc.c index 79a5da1bc5bb..482805f6ea68 100644 --- a/kernel/auditsc.c +++ b/kernel/auditsc.c @@ -664,7 +664,7 @@ static int audit_filter_rules(struct task_struct *tsk, match for now to avoid losing information that may be wanted. An error message will also be logged upon error */ - if (f->lsm_rule) { + if (f->lsm_str) { if (need_sid) { /* @tsk should always be equal to * @current with the exception of @@ -679,8 +679,7 @@ static int audit_filter_rules(struct task_struct *tsk, need_sid = 0; } result = security_audit_rule_match(sid, f->type, - f->op, - f->lsm_rule); + f->op, &f->lsm_rules); } break; case AUDIT_OBJ_USER: @@ -690,21 +689,19 @@ static int audit_filter_rules(struct task_struct *tsk, case AUDIT_OBJ_LEV_HIGH: /* The above note for AUDIT_SUBJ_USER...AUDIT_SUBJ_CLR also applies here */ - if (f->lsm_rule) { + if (f->lsm_str) { /* Find files that match */ if (name) { result = security_audit_rule_match( name->osid, f->type, f->op, - f->lsm_rule); + &f->lsm_rules); } else if (ctx) { list_for_each_entry(n, &ctx->names_list, list) { if (security_audit_rule_match( - n->osid, - f->type, - f->op, - f->lsm_rule)) { + n->osid, f->type, f->op, + &f->lsm_rules)) { ++result; break; } @@ -715,7 +712,7 @@ static int audit_filter_rules(struct task_struct *tsk, break; if (security_audit_rule_match(ctx->ipc.osid, f->type, f->op, - f->lsm_rule)) + &f->lsm_rules)) ++result; } break; diff --git a/security/apparmor/lsm.c b/security/apparmor/lsm.c index caad42a0c913..25423a3aa572 100644 --- a/security/apparmor/lsm.c +++ b/security/apparmor/lsm.c @@ -1190,6 +1190,7 @@ static struct lsm_id apparmor_lsmid __lsm_ro_after_init = { .lsm = "apparmor", .id = LSM_ID_APPARMOR, .features = LSM_ATTR_CURRENT | LSM_ATTR_PREV | LSM_ATTR_EXEC, + .slot = LSMBLOB_NEEDED, }; static struct security_hook_list apparmor_hooks[] __lsm_ro_after_init = { diff --git a/security/bpf/hooks.c b/security/bpf/hooks.c index c462fc41dd57..d92a21ca3d1b 100644 --- a/security/bpf/hooks.c +++ b/security/bpf/hooks.c @@ -23,6 +23,7 @@ static struct security_hook_list bpf_lsm_hooks[] __lsm_ro_after_init = { struct lsm_id bpf_lsmid __lsm_ro_after_init = { .lsm = "bpf", .id = LSM_ID_BPF, + .slot = LSMBLOB_NEEDED, }; static int __init bpf_lsm_init(void) diff --git a/security/commoncap.c b/security/commoncap.c index 4e9b140159d8..29c7642a9fb5 100644 --- a/security/commoncap.c +++ b/security/commoncap.c @@ -1450,6 +1450,7 @@ int cap_mmap_file(struct file *file, unsigned long reqprot, static struct lsm_id capability_lsmid __lsm_ro_after_init = { .lsm = "capability", .id = LSM_ID_CAPABILITY, + .slot = LSMBLOB_NOT_NEEDED, }; static struct security_hook_list capability_hooks[] __lsm_ro_after_init = { diff --git a/security/landlock/setup.c b/security/landlock/setup.c index 1242c61c9de4..adbe941370f3 100644 --- a/security/landlock/setup.c +++ b/security/landlock/setup.c @@ -27,6 +27,7 @@ struct lsm_blob_sizes landlock_blob_sizes __lsm_ro_after_init = { struct lsm_id landlock_lsmid __lsm_ro_after_init = { .lsm = LANDLOCK_NAME, .id = LSM_ID_LANDLOCK, + .slot = LSMBLOB_NOT_NEEDED, }; static int __init landlock_init(void) diff --git a/security/loadpin/loadpin.c b/security/loadpin/loadpin.c index 276c8a7cd6fe..c3f5678b92c4 100644 --- a/security/loadpin/loadpin.c +++ b/security/loadpin/loadpin.c @@ -199,6 +199,7 @@ static int loadpin_load_data(enum kernel_load_data_id id, bool contents) static struct lsm_id loadpin_lsmid __lsm_ro_after_init = { .lsm = "loadpin", .id = LSM_ID_LOADPIN, + .slot = LSMBLOB_NOT_NEEDED, }; static struct security_hook_list loadpin_hooks[] __lsm_ro_after_init = { diff --git a/security/lockdown/lockdown.c b/security/lockdown/lockdown.c index 3d3347f3dbd1..1f87e8d43387 100644 --- a/security/lockdown/lockdown.c +++ b/security/lockdown/lockdown.c @@ -79,6 +79,7 @@ static struct security_hook_list lockdown_hooks[] __lsm_ro_after_init = { static struct lsm_id lockdown_lsmid __lsm_ro_after_init = { .lsm = "lockdown", .id = LSM_ID_LOCKDOWN, + .slot = LSMBLOB_NOT_NEEDED, }; static int __init lockdown_lsm_init(void) diff --git a/security/safesetid/lsm.c b/security/safesetid/lsm.c index 88002731e603..bddf9a28c270 100644 --- a/security/safesetid/lsm.c +++ b/security/safesetid/lsm.c @@ -265,6 +265,7 @@ static int safesetid_task_fix_setgroups(struct cred *new, const struct cred *old static struct lsm_id safesetid_lsmid __lsm_ro_after_init = { .lsm = "safesetid", .id = LSM_ID_SAFESETID, + .slot = LSMBLOB_NOT_NEEDED, }; static struct security_hook_list safesetid_security_hooks[] = { diff --git a/security/security.c b/security/security.c index 7a604a74716a..b837500cb3dc 100644 --- a/security/security.c +++ b/security/security.c @@ -354,6 +354,7 @@ static void __init ordered_lsm_init(void) init_debug("sock blob size = %d\n", blob_sizes.lbs_sock); init_debug("superblock blob size = %d\n", blob_sizes.lbs_superblock); init_debug("task blob size = %d\n", blob_sizes.lbs_task); + init_debug("lsmblob size = %zu\n", sizeof(struct lsmblob)); /* * Create any kmem_caches needed for blobs @@ -481,6 +482,11 @@ static int lsm_append(const char *new, char **result) return 0; } +/* + * Current index to use while initializing the lsmblob secid list. + */ +static int lsm_slot __lsm_ro_after_init; + /** * security_add_hooks - Add a modules hooks to the hook lists. * @hooks: the hooks to add @@ -488,6 +494,8 @@ static int lsm_append(const char *new, char **result) * @lsmid: the identification information for the security module * * Each LSM has to register its hooks with the infrastructure. + * If the LSM is using hooks that export secids allocate a slot + * for it in the lsmblob. */ void __init security_add_hooks(struct security_hook_list *hooks, int count, struct lsm_id *lsmid) @@ -504,6 +512,16 @@ void __init security_add_hooks(struct security_hook_list *hooks, int count, if (lsm_id > LSMID_ENTRIES) panic("%s Too many LSMs registered.\n", __func__); + WARN_ON(!lsmid->slot || !lsmid->id); + + if (lsmid->slot == LSMBLOB_NEEDED) { + if (lsm_slot >= LSMBLOB_ENTRIES) + panic("%s Too many LSMs registered.\n", __func__); + lsmid->slot = lsm_slot++; + init_debug("%s assigned lsmblob slot %d\n", lsmid->lsm, + lsmid->slot); + } + for (i = 0; i < count; i++) { hooks[i].lsmid = lsmid; hlist_add_tail_rcu(&hooks[i].list, hooks[i].head); @@ -2616,9 +2634,27 @@ int security_key_getsecurity(struct key *key, char **_buffer) #ifdef CONFIG_AUDIT -int security_audit_rule_init(u32 field, u32 op, char *rulestr, void **lsmrule) +int security_audit_rule_init(u32 field, u32 op, char *rulestr, + struct audit_lsm_rules *lsmrules) { - return call_int_hook(audit_rule_init, 0, field, op, rulestr, lsmrule); + struct security_hook_list *hp; + bool one_is_good = false; + int rc = 0; + int trc; + + hlist_for_each_entry(hp, &security_hook_heads.audit_rule_init, list) { + if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >= lsm_slot)) + continue; + trc = hp->hook.audit_rule_init(field, op, rulestr, + &lsmrules->rule[hp->lsmid->slot]); + if (trc == 0) + one_is_good = true; + else + rc = trc; + } + if (one_is_good) + return 0; + return rc; } int security_audit_rule_known(struct audit_krule *krule) @@ -2626,14 +2662,36 @@ int security_audit_rule_known(struct audit_krule *krule) return call_int_hook(audit_rule_known, 0, krule); } -void security_audit_rule_free(void *lsmrule) +void security_audit_rule_free(struct audit_lsm_rules *lsmrules) { - call_void_hook(audit_rule_free, lsmrule); + struct security_hook_list *hp; + + hlist_for_each_entry(hp, &security_hook_heads.audit_rule_free, list) { + if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >= lsm_slot)) + continue; + if (lsmrules->rule[hp->lsmid->slot] == NULL) + continue; + hp->hook.audit_rule_free(lsmrules->rule[hp->lsmid->slot]); + } } -int security_audit_rule_match(u32 secid, u32 field, u32 op, void *lsmrule) +int security_audit_rule_match(u32 secid, u32 field, u32 op, + struct audit_lsm_rules *lsmrules) { - return call_int_hook(audit_rule_match, 0, secid, field, op, lsmrule); + struct security_hook_list *hp; + int rc; + + hlist_for_each_entry(hp, &security_hook_heads.audit_rule_match, list) { + if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >= lsm_slot)) + continue; + if (lsmrules->rule[hp->lsmid->slot] == NULL) + continue; + rc = hp->hook.audit_rule_match(secid, field, op, + &lsmrules->rule[hp->lsmid->slot]); + if (rc) + return rc; + } + return 0; } #endif /* CONFIG_AUDIT */ diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index 25cc17bdd33c..cf89ccaa018d 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -7014,6 +7014,7 @@ static struct lsm_id selinux_lsmid __lsm_ro_after_init = { .id = LSM_ID_SELINUX, .features = LSM_ATTR_CURRENT | LSM_ATTR_EXEC | LSM_ATTR_FSCREATE | LSM_ATTR_KEYCREATE | LSM_ATTR_PREV | LSM_ATTR_SOCKCREATE, + .slot = LSMBLOB_NEEDED, }; /* diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c index c399ed799ceb..fbcf20ef1394 100644 --- a/security/smack/smack_lsm.c +++ b/security/smack/smack_lsm.c @@ -4773,6 +4773,7 @@ static struct lsm_id smack_lsmid __lsm_ro_after_init = { .lsm = "smack", .id = LSM_ID_SMACK, .features = LSM_ATTR_CURRENT, + .slot = LSMBLOB_NEEDED, }; static struct security_hook_list smack_hooks[] __lsm_ro_after_init = { diff --git a/security/tomoyo/tomoyo.c b/security/tomoyo/tomoyo.c index 71eab206ba6e..78b11332eb5b 100644 --- a/security/tomoyo/tomoyo.c +++ b/security/tomoyo/tomoyo.c @@ -534,6 +534,7 @@ static void tomoyo_task_free(struct task_struct *task) static struct lsm_id tomoyo_lsmid __lsm_ro_after_init = { .lsm = "tomoyo", .id = LSM_ID_TOMOYO, + .slot = LSMBLOB_NOT_NEEDED, }; /* diff --git a/security/yama/yama_lsm.c b/security/yama/yama_lsm.c index b178d74bb00b..e11dd71553f4 100644 --- a/security/yama/yama_lsm.c +++ b/security/yama/yama_lsm.c @@ -425,6 +425,7 @@ static int yama_ptrace_traceme(struct task_struct *parent) static struct lsm_id yama_lsmid __lsm_ro_after_init = { .lsm = "yama", .id = LSM_ID_YAMA, + .slot = LSMBLOB_NOT_NEEDED, }; static struct security_hook_list yama_hooks[] __lsm_ro_after_init = { -- 2.37.3

Provide interfaces to map LSM slot numbers and LSM names. Update the LSM registration code to save this information. Acked-by: Paul Moore <paul(a)paul-moore.com&gt; Reviewed-by: Kees Cook <keescook(a)chromium.org&gt; Signed-off-by: Casey Schaufler <casey(a)schaufler-ca.com&gt; --- include/linux/security.h | 4 ++++ security/security.c | 45 ++++++++++++++++++++++++++++++++++++++++ 2 files changed, 49 insertions(+) diff --git a/include/linux/security.h b/include/linux/security.h index c1f8b33e7c27..0f0fb2077f41 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -214,6 +214,10 @@ static inline bool lsmblob_equal(const struct lsmblob *bloba, return !memcmp(bloba, blobb, sizeof(*bloba)); } +/* Map lsm names to blob slot numbers */ +extern int lsm_name_to_slot(char *name); +extern const char *lsm_slot_to_name(int slot); + /* These functions are in security/commoncap.c */ extern int cap_capable(const struct cred *cred, struct user_namespace *ns, int cap, unsigned int opts); diff --git a/security/security.c b/security/security.c index b837500cb3dc..2c197c25746c 100644 --- a/security/security.c +++ b/security/security.c @@ -486,6 +486,50 @@ static int lsm_append(const char *new, char **result) * Current index to use while initializing the lsmblob secid list. */ static int lsm_slot __lsm_ro_after_init; +static struct lsm_id *lsm_slotlist[LSMBLOB_ENTRIES] __lsm_ro_after_init; + +/** + * lsm_name_to_slot - Report the slot number for a security module + * @name: name of the security module + * + * Look up the slot number for the named security module. + * Returns the slot number or LSMBLOB_INVALID if @name is not + * a registered security module name. + */ +int lsm_name_to_slot(char *name) +{ + int i; + + for (i = 0; i < lsm_slot; i++) + if (strcmp(lsm_slotlist[i]->lsm, name) == 0) + return i; + + return LSMBLOB_INVALID; +} + +/** + * lsm_slot_to_name - Get the name of the security module in a slot + * @slot: index into the interface LSM slot list. + * + * Provide the name of the security module associated with + * a interface LSM slot. + * + * If @slot is LSMBLOB_INVALID return the value + * for slot 0 if it has been set, otherwise NULL. + * + * Returns a pointer to the name string or NULL. + */ +const char *lsm_slot_to_name(int slot) +{ + if (slot == LSMBLOB_INVALID) + slot = 0; + else if (slot >= LSMBLOB_ENTRIES || slot < 0) + return NULL; + + if (lsm_slotlist[slot] == NULL) + return NULL; + return lsm_slotlist[slot]->lsm; +} /** * security_add_hooks - Add a modules hooks to the hook lists. @@ -517,6 +561,7 @@ void __init security_add_hooks(struct security_hook_list *hooks, int count, if (lsmid->slot == LSMBLOB_NEEDED) { if (lsm_slot >= LSMBLOB_ENTRIES) panic("%s Too many LSMs registered.\n", __func__); + lsm_slotlist[lsm_slot] = lsmid; lsmid->slot = lsm_slot++; init_debug("%s assigned lsmblob slot %d\n", lsmid->lsm, lsmid->slot); -- 2.37.3

Change the secid parameter of security_audit_rule_match to a lsmblob structure pointer. Pass the entry from the lsmblob structure for the approprite slot to the LSM hook. Change the users of security_audit_rule_match to use the lsmblob instead of a u32. The scaffolding function lsmblob_init() fills the blob with the value of the old secid, ensuring that it is available to the appropriate module hook. The sources of the secid, security_task_getsecid() and security_inode_getsecid(), will be converted to use the blob structure later in the series. At the point the use of lsmblob_init() is dropped. Signed-off-by: Casey Schaufler <casey(a)schaufler-ca.com&gt; Acked-by: Paul Moore <paul(a)paul-moore.com&gt; Reviewed-by: John Johansen <john.johansen(a)canonical.com&gt; Cc: linux-audit(a)redhat.com --- include/linux/security.h | 5 +++-- kernel/auditfilter.c | 6 ++++-- kernel/auditsc.c | 16 +++++++++++----- security/security.c | 5 +++-- 4 files changed, 21 insertions(+), 11 deletions(-) diff --git a/include/linux/security.h b/include/linux/security.h index 6ee00f3a10a7..3fe04958f7fb 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -1982,7 +1982,7 @@ static inline int security_key_getsecurity(struct key *key, char **_buffer) int security_audit_rule_init(u32 field, u32 op, char *rulestr, struct audit_lsm_rules *lsmrules); int security_audit_rule_known(struct audit_krule *krule); -int security_audit_rule_match(u32 secid, u32 field, u32 op, +int security_audit_rule_match(struct lsmblob *blob, u32 field, u32 op, struct audit_lsm_rules *lsmrules); void security_audit_rule_free(struct audit_lsm_rules *lsmrules); @@ -1999,7 +1999,8 @@ static inline int security_audit_rule_known(struct audit_krule *krule) return 0; } -static inline int security_audit_rule_match(u32 secid, u32 field, u32 op, +static inline int security_audit_rule_match(struct lsmblob *blob, + u32 field, u32 op, struct audit_lsm_rules *lsmrules) { return 0; diff --git a/kernel/auditfilter.c b/kernel/auditfilter.c index de75bd6ad866..15cd4fe35e9c 100644 --- a/kernel/auditfilter.c +++ b/kernel/auditfilter.c @@ -1337,6 +1337,7 @@ int audit_filter(int msgtype, unsigned int listtype) for (i = 0; i < e->rule.field_count; i++) { struct audit_field *f = &e->rule.fields[i]; + struct lsmblob blob; pid_t pid; u32 sid; @@ -1369,8 +1370,9 @@ int audit_filter(int msgtype, unsigned int listtype) case AUDIT_SUBJ_CLR: if (f->lsm_str) { security_current_getsecid_subj(&sid); - result = security_audit_rule_match(sid, - f->type, f->op, + lsmblob_init(&blob, sid); + result = security_audit_rule_match( + &blob, f->type, f->op, &f->lsm_rules); } break; diff --git a/kernel/auditsc.c b/kernel/auditsc.c index 482805f6ea68..5fab2367bfd0 100644 --- a/kernel/auditsc.c +++ b/kernel/auditsc.c @@ -468,6 +468,7 @@ static int audit_filter_rules(struct task_struct *tsk, const struct cred *cred; int i, need_sid = 1; u32 sid; + struct lsmblob blob; unsigned int sessionid; if (ctx && rule->prio <= ctx->prio) @@ -678,8 +679,10 @@ static int audit_filter_rules(struct task_struct *tsk, security_current_getsecid_subj(&sid); need_sid = 0; } - result = security_audit_rule_match(sid, f->type, - f->op, &f->lsm_rules); + lsmblob_init(&blob, sid); + result = security_audit_rule_match(&blob, + f->type, f->op, + &f->lsm_rules); } break; case AUDIT_OBJ_USER: @@ -692,15 +695,17 @@ static int audit_filter_rules(struct task_struct *tsk, if (f->lsm_str) { /* Find files that match */ if (name) { + lsmblob_init(&blob, name->osid); result = security_audit_rule_match( - name->osid, + &blob, f->type, f->op, &f->lsm_rules); } else if (ctx) { list_for_each_entry(n, &ctx->names_list, list) { + lsmblob_init(&blob, n->osid); if (security_audit_rule_match( - n->osid, f->type, f->op, + &blob, f->type, f->op, &f->lsm_rules)) { ++result; break; @@ -710,7 +715,8 @@ static int audit_filter_rules(struct task_struct *tsk, /* Find ipc objects that match */ if (!ctx || ctx->type != AUDIT_IPC) break; - if (security_audit_rule_match(ctx->ipc.osid, + lsmblob_init(&blob, ctx->ipc.osid); + if (security_audit_rule_match(&blob, f->type, f->op, &f->lsm_rules)) ++result; diff --git a/security/security.c b/security/security.c index b74debe82d82..96faeff2c73b 100644 --- a/security/security.c +++ b/security/security.c @@ -2720,7 +2720,7 @@ void security_audit_rule_free(struct audit_lsm_rules *lsmrules) } } -int security_audit_rule_match(u32 secid, u32 field, u32 op, +int security_audit_rule_match(struct lsmblob *blob, u32 field, u32 op, struct audit_lsm_rules *lsmrules) { struct security_hook_list *hp; @@ -2731,7 +2731,8 @@ int security_audit_rule_match(u32 secid, u32 field, u32 op, continue; if (lsmrules->rule[hp->lsmid->slot] == NULL) continue; - rc = hp->hook.audit_rule_match(secid, field, op, + rc = hp->hook.audit_rule_match(blob->secid[hp->lsmid->slot], + field, op, &lsmrules->rule[hp->lsmid->slot]); if (rc) return rc; -- 2.37.3

Change the security_secctx_to_secid interface to use a lsmblob structure in place of the single u32 secid in support of module stacking. Change its callers to do the same. The security module hook is unchanged, still passing back a secid. The infrastructure passes the correct entry from the lsmblob. Acked-by: Paul Moore <paul(a)paul-moore.com&gt; Reviewed-by: Kees Cook <keescook(a)chromium.org&gt; Signed-off-by: Casey Schaufler <casey(a)schaufler-ca.com&gt; Cc: netdev(a)vger.kernel.org Cc: netfilter-devel(a)vger.kernel.org To: Pablo Neira Ayuso <pablo(a)netfilter.org&gt; --- include/linux/security.h | 26 ++++++++++++++++++-- kernel/cred.c | 4 +--- net/netfilter/nft_meta.c | 10 ++++---- net/netfilter/xt_SECMARK.c | 7 +++++- net/netlabel/netlabel_unlabeled.c | 23 +++++++++++------- security/security.c | 40 ++++++++++++++++++++++++++----- 6 files changed, 85 insertions(+), 25 deletions(-) diff --git a/include/linux/security.h b/include/linux/security.h index e95801437328..0134a938fd65 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -218,6 +218,27 @@ static inline bool lsmblob_equal(const struct lsmblob *bloba, extern int lsm_name_to_slot(char *name); extern const char *lsm_slot_to_name(int slot); +/** + * lsmblob_value - find the first non-zero value in an lsmblob structure. + * @blob: Pointer to the data + * + * This needs to be used with extreme caution, as the cases where + * it is appropriate are rare. + * + * Return the first secid value set in the lsmblob. + * There should only be one. + */ +static inline u32 lsmblob_value(const struct lsmblob *blob) +{ + int i; + + for (i = 0; i < LSMBLOB_ENTRIES; i++) + if (blob->secid[i]) + return blob->secid[i]; + + return 0; +} + /* These functions are in security/commoncap.c */ extern int cap_capable(const struct cred *cred, struct user_namespace *ns, int cap, unsigned int opts); @@ -549,7 +570,8 @@ int security_setprocattr(int lsmid, const char *name, void *value, size_t size); int security_netlink_send(struct sock *sk, struct sk_buff *skb); int security_ismaclabel(const char *name); int security_secid_to_secctx(u32 secid, char **secdata, u32 *seclen); -int security_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid); +int security_secctx_to_secid(const char *secdata, u32 seclen, + struct lsmblob *blob); void security_release_secctx(char *secdata, u32 seclen); void security_inode_invalidate_secctx(struct inode *inode); int security_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen); @@ -1411,7 +1433,7 @@ static inline int security_secid_to_secctx(u32 secid, char **secdata, u32 *secle static inline int security_secctx_to_secid(const char *secdata, u32 seclen, - u32 *secid) + struct lsmblob *blob) { return -EOPNOTSUPP; } diff --git a/kernel/cred.c b/kernel/cred.c index 3925d38f49f4..adea727744f4 100644 --- a/kernel/cred.c +++ b/kernel/cred.c @@ -791,14 +791,12 @@ EXPORT_SYMBOL(set_security_override); int set_security_override_from_ctx(struct cred *new, const char *secctx) { struct lsmblob blob; - u32 secid; int ret; - ret = security_secctx_to_secid(secctx, strlen(secctx), &secid); + ret = security_secctx_to_secid(secctx, strlen(secctx), &blob); if (ret < 0) return ret; - lsmblob_init(&blob, secid); return set_security_override(new, &blob); } EXPORT_SYMBOL(set_security_override_from_ctx); diff --git a/net/netfilter/nft_meta.c b/net/netfilter/nft_meta.c index 55d2d49c3425..2c6edee9fbea 100644 --- a/net/netfilter/nft_meta.c +++ b/net/netfilter/nft_meta.c @@ -851,21 +851,21 @@ static const struct nla_policy nft_secmark_policy[NFTA_SECMARK_MAX + 1] = { static int nft_secmark_compute_secid(struct nft_secmark *priv) { - u32 tmp_secid = 0; + struct lsmblob blob; int err; - err = security_secctx_to_secid(priv->ctx, strlen(priv->ctx), &tmp_secid); + err = security_secctx_to_secid(priv->ctx, strlen(priv->ctx), &blob); if (err) return err; - if (!tmp_secid) + if (!lsmblob_is_set(&blob)) return -ENOENT; - err = security_secmark_relabel_packet(tmp_secid); + err = security_secmark_relabel_packet(lsmblob_value(&blob)); if (err) return err; - priv->secid = tmp_secid; + priv->secid = lsmblob_value(&blob); return 0; } diff --git a/net/netfilter/xt_SECMARK.c b/net/netfilter/xt_SECMARK.c index 498a0bf6f044..87ca3a537d1c 100644 --- a/net/netfilter/xt_SECMARK.c +++ b/net/netfilter/xt_SECMARK.c @@ -42,13 +42,14 @@ secmark_tg(struct sk_buff *skb, const struct xt_secmark_target_info_v1 *info) static int checkentry_lsm(struct xt_secmark_target_info_v1 *info) { + struct lsmblob blob; int err; info->secctx[SECMARK_SECCTX_MAX - 1] = '\0'; info->secid = 0; err = security_secctx_to_secid(info->secctx, strlen(info->secctx), - &info->secid); + &blob); if (err) { if (err == -EINVAL) pr_info_ratelimited("invalid security context \'%s\'\n", @@ -56,6 +57,10 @@ static int checkentry_lsm(struct xt_secmark_target_info_v1 *info) return err; } + /* xt_secmark_target_info can't be changed to use lsmblobs because + * it is exposed as an API. Use lsmblob_value() to get the one + * value that got set by security_secctx_to_secid(). */ + info->secid = lsmblob_value(&blob); if (!info->secid) { pr_info_ratelimited("unable to map security context \'%s\'\n", info->secctx); diff --git a/net/netlabel/netlabel_unlabeled.c b/net/netlabel/netlabel_unlabeled.c index 0555dffd80e0..87fb0747d3e9 100644 --- a/net/netlabel/netlabel_unlabeled.c +++ b/net/netlabel/netlabel_unlabeled.c @@ -880,7 +880,7 @@ static int netlbl_unlabel_staticadd(struct sk_buff *skb, void *addr; void *mask; u32 addr_len; - u32 secid; + struct lsmblob blob; struct netlbl_audit audit_info; /* Don't allow users to add both IPv4 and IPv6 addresses for a @@ -904,13 +904,18 @@ static int netlbl_unlabel_staticadd(struct sk_buff *skb, ret_val = security_secctx_to_secid( nla_data(info->attrs[NLBL_UNLABEL_A_SECCTX]), nla_len(info->attrs[NLBL_UNLABEL_A_SECCTX]), - &secid); + &blob); if (ret_val != 0) return ret_val; + /* netlbl_unlhsh_add will be changed to pass a struct lsmblob * + * instead of a u32 later in this patch set. security_secctx_to_secid() + * will only be setting one entry in the lsmblob struct, so it is + * safe to use lsmblob_value() to get that one value. */ + return netlbl_unlhsh_add(&init_net, - dev_name, addr, mask, addr_len, secid, - &audit_info); + dev_name, addr, mask, addr_len, + lsmblob_value(&blob), &audit_info); } /** @@ -931,7 +936,7 @@ static int netlbl_unlabel_staticadddef(struct sk_buff *skb, void *addr; void *mask; u32 addr_len; - u32 secid; + struct lsmblob blob; struct netlbl_audit audit_info; /* Don't allow users to add both IPv4 and IPv6 addresses for a @@ -953,13 +958,15 @@ static int netlbl_unlabel_staticadddef(struct sk_buff *skb, ret_val = security_secctx_to_secid( nla_data(info->attrs[NLBL_UNLABEL_A_SECCTX]), nla_len(info->attrs[NLBL_UNLABEL_A_SECCTX]), - &secid); + &blob); if (ret_val != 0) return ret_val; + /* security_secctx_to_secid() will only put one secid into the lsmblob + * so it's safe to use lsmblob_value() to get the secid. */ return netlbl_unlhsh_add(&init_net, - NULL, addr, mask, addr_len, secid, - &audit_info); + NULL, addr, mask, addr_len, + lsmblob_value(&blob), &audit_info); } /** diff --git a/security/security.c b/security/security.c index ca749a8f36b8..0c5be69d8146 100644 --- a/security/security.c +++ b/security/security.c @@ -2228,10 +2228,22 @@ int security_secid_to_secctx(u32 secid, char **secdata, u32 *seclen) } EXPORT_SYMBOL(security_secid_to_secctx); -int security_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid) +int security_secctx_to_secid(const char *secdata, u32 seclen, + struct lsmblob *blob) { - *secid = 0; - return call_int_hook(secctx_to_secid, 0, secdata, seclen, secid); + struct security_hook_list *hp; + int rc; + + lsmblob_init(blob, 0); + hlist_for_each_entry(hp, &security_hook_heads.secctx_to_secid, list) { + if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >= lsm_slot)) + continue; + rc = hp->hook.secctx_to_secid(secdata, seclen, + &blob->secid[hp->lsmid->slot]); + if (rc != 0) + return rc; + } + return 0; } EXPORT_SYMBOL(security_secctx_to_secid); @@ -2382,10 +2394,26 @@ int security_socket_getpeersec_stream(struct socket *sock, char __user *optval, optval, optlen, len); } -int security_socket_getpeersec_dgram(struct socket *sock, struct sk_buff *skb, u32 *secid) +int security_socket_getpeersec_dgram(struct socket *sock, struct sk_buff *skb, + u32 *secid) { - return call_int_hook(socket_getpeersec_dgram, -ENOPROTOOPT, sock, - skb, secid); + struct security_hook_list *hp; + int rc = -ENOPROTOOPT; + + /* + * Only one security module should provide a real hook for + * this. A stub or bypass like is used in BPF should either + * (somehow) leave rc unaltered or return -ENOPROTOOPT. + */ + hlist_for_each_entry(hp, &security_hook_heads.socket_getpeersec_dgram, + list) { + if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >= lsm_slot)) + continue; + rc = hp->hook.socket_getpeersec_dgram(sock, skb, secid); + if (rc != -ENOPROTOOPT) + break; + } + return rc; } EXPORT_SYMBOL(security_socket_getpeersec_dgram); -- 2.37.3

There may be more than one LSM that provides IPC data for auditing. Change security_ipc_getsecid() to fill in a lsmblob structure instead of the u32 secid. The audit data structure containing the secid will be updated later, so there is a bit of scaffolding here. Reviewed-by: Kees Cook <keescook(a)chromium.org&gt; Reviewed-by: John Johansen <john.johansen(a)canonical.com&gt; Acked-by: Stephen Smalley <stephen.smalley.work(a)gmail.com&gt; Acked-by: Paul Moore <paul(a)paul-moore.com&gt; Signed-off-by: Casey Schaufler <casey(a)schaufler-ca.com&gt; Cc: linux-audit(a)redhat.com --- include/linux/security.h | 7 ++++--- kernel/auditsc.c | 7 ++++++- security/security.c | 12 +++++++++--- 3 files changed, 19 insertions(+), 7 deletions(-) diff --git a/include/linux/security.h b/include/linux/security.h index d9ab76c909e0..bedb2047138b 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -541,7 +541,7 @@ int security_task_prctl(int option, unsigned long arg2, unsigned long arg3, unsigned long arg4, unsigned long arg5); void security_task_to_inode(struct task_struct *p, struct inode *inode); int security_ipc_permission(struct kern_ipc_perm *ipcp, short flag); -void security_ipc_getsecid(struct kern_ipc_perm *ipcp, u32 *secid); +void security_ipc_getsecid(struct kern_ipc_perm *ipcp, struct lsmblob *blob); int security_msg_msg_alloc(struct msg_msg *msg); void security_msg_msg_free(struct msg_msg *msg); int security_msg_queue_alloc(struct kern_ipc_perm *msq); @@ -1304,9 +1304,10 @@ static inline int security_ipc_permission(struct kern_ipc_perm *ipcp, return 0; } -static inline void security_ipc_getsecid(struct kern_ipc_perm *ipcp, u32 *secid) +static inline void security_ipc_getsecid(struct kern_ipc_perm *ipcp, + struct lsmblob *blob) { - *secid = 0; + lsmblob_init(blob, 0); } static inline int security_msg_msg_alloc(struct msg_msg *msg) diff --git a/kernel/auditsc.c b/kernel/auditsc.c index d083c050d660..9eb2d84439da 100644 --- a/kernel/auditsc.c +++ b/kernel/auditsc.c @@ -2643,12 +2643,17 @@ void __audit_mq_getsetattr(mqd_t mqdes, struct mq_attr *mqstat) void __audit_ipc_obj(struct kern_ipc_perm *ipcp) { struct audit_context *context = audit_context(); + struct lsmblob blob; context->ipc.uid = ipcp->uid; context->ipc.gid = ipcp->gid; context->ipc.mode = ipcp->mode; context->ipc.has_perm = 0; - security_ipc_getsecid(ipcp, &context->ipc.osid); + security_ipc_getsecid(ipcp, &blob); + /* context->ipc.osid will be changed to a lsmblob later in + * the patch series. This will allow auditing of all the object + * labels associated with the ipc object. */ + context->ipc.osid = lsmblob_value(&blob); context->type = AUDIT_IPC; } diff --git a/security/security.c b/security/security.c index 9c49406e5ff9..afd6f6698fd7 100644 --- a/security/security.c +++ b/security/security.c @@ -2030,10 +2030,16 @@ int security_ipc_permission(struct kern_ipc_perm *ipcp, short flag) return call_int_hook(ipc_permission, 0, ipcp, flag); } -void security_ipc_getsecid(struct kern_ipc_perm *ipcp, u32 *secid) +void security_ipc_getsecid(struct kern_ipc_perm *ipcp, struct lsmblob *blob) { - *secid = 0; - call_void_hook(ipc_getsecid, ipcp, secid); + struct security_hook_list *hp; + + lsmblob_init(blob, 0); + hlist_for_each_entry(hp, &security_hook_heads.ipc_getsecid, list) { + if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >= lsm_slot)) + continue; + hp->hook.ipc_getsecid(ipcp, &blob->secid[hp->lsmid->slot]); + } } int security_msg_msg_alloc(struct msg_msg *msg) -- 2.37.3

Change the security_inode_getsecid() interface to fill in a lsmblob structure instead of a u32 secid. This allows for its callers to gather data from all registered LSMs. Data is provided for IMA and audit. Reviewed-by: Kees Cook <keescook(a)chromium.org&gt; Reviewed-by: John Johansen <john.johansen(a)canonical.com&gt; Acked-by: Stephen Smalley <stephen.smalley.work(a)gmail.com&gt; Acked-by: Paul Moore <paul(a)paul-moore.com&gt; Signed-off-by: Casey Schaufler <casey(a)schaufler-ca.com&gt; Cc: linux-integrity(a)vger.kernel.org Cc: linux-audit(a)redhat.com --- include/linux/security.h | 13 +++++++------ kernel/auditsc.c | 6 +++++- security/integrity/ima/ima_policy.c | 9 +++++---- security/security.c | 19 +++++++++++++------ 4 files changed, 30 insertions(+), 17 deletions(-) diff --git a/include/linux/security.h b/include/linux/security.h index 142ecbf4dfc9..ca5dcaee7c23 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -494,7 +494,7 @@ int security_inode_getsecurity(struct user_namespace *mnt_userns, void **buffer, bool alloc); int security_inode_setsecurity(struct inode *inode, const char *name, const void *value, size_t size, int flags); int security_inode_listsecurity(struct inode *inode, char *buffer, size_t buffer_size); -void security_inode_getsecid(struct inode *inode, u32 *secid); +void security_inode_getsecid(struct inode *inode, struct lsmblob *blob); int security_inode_copy_up(struct dentry *src, struct cred **new); int security_inode_copy_up_xattr(const char *name); int security_kernfs_init_security(struct kernfs_node *kn_dir, @@ -1041,9 +1041,10 @@ static inline int security_inode_listsecurity(struct inode *inode, char *buffer, return 0; } -static inline void security_inode_getsecid(struct inode *inode, u32 *secid) +static inline void security_inode_getsecid(struct inode *inode, + struct lsmblob *blob) { - *secid = 0; + lsmblob_init(blob, 0); } static inline int security_inode_copy_up(struct dentry *src, struct cred **new) @@ -2059,8 +2060,8 @@ static inline void security_audit_rule_free(struct audit_lsm_rules *lsmrules) #if defined(CONFIG_IMA_LSM_RULES) && defined(CONFIG_SECURITY) int ima_filter_rule_init(u32 field, u32 op, char *rulestr, void **lsmrule, int lsmslot); -int ima_filter_rule_match(u32 secid, u32 field, u32 op, void *lsmrule, - int lsmslot); +int ima_filter_rule_match(struct lsmblob *blob, u32 field, u32 op, + void *lsmrule, int lsmslot); void ima_filter_rule_free(void *lsmrule, int lsmslot); #else @@ -2071,7 +2072,7 @@ static inline int ima_filter_rule_init(u32 field, u32 op, char *rulestr, return 0; } -static inline int ima_filter_rule_match(u32 secid, u32 field, u32 op, +static inline int ima_filter_rule_match(struct lsmblob *blob, u32 field, u32 op, void *lsmrule, int lsmslot) { return 0; diff --git a/kernel/auditsc.c b/kernel/auditsc.c index b2879bdf45d8..ad5f33af3b50 100644 --- a/kernel/auditsc.c +++ b/kernel/auditsc.c @@ -2281,13 +2281,17 @@ static void audit_copy_inode(struct audit_names *name, const struct dentry *dentry, struct inode *inode, unsigned int flags) { + struct lsmblob blob; + name->ino = inode->i_ino; name->dev = inode->i_sb->s_dev; name->mode = inode->i_mode; name->uid = inode->i_uid; name->gid = inode->i_gid; name->rdev = inode->i_rdev; - security_inode_getsecid(inode, &name->osid); + security_inode_getsecid(inode, &blob); + /* scaffolding until osid is updated */ + name->osid = lsmblob_first(&blob); if (flags & AUDIT_INODE_NOEVAL) { name->fcap_ver = -1; return; diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c index 2e1aadd36482..e8693939447b 100644 --- a/security/integrity/ima/ima_policy.c +++ b/security/integrity/ima/ima_policy.c @@ -636,7 +636,7 @@ static bool ima_match_rules(struct ima_rule_entry *rule, return false; for (i = 0; i < MAX_LSM_RULES; i++) { int rc = 0; - u32 osid; + struct lsmblob lsmdata; if (!rule->lsm[i].rule) { if (!rule->lsm[i].args_p) @@ -648,8 +648,9 @@ static bool ima_match_rules(struct ima_rule_entry *rule, case LSM_OBJ_USER: case LSM_OBJ_ROLE: case LSM_OBJ_TYPE: - security_inode_getsecid(inode, &osid); - rc = ima_filter_rule_match(osid, rule->lsm[i].type, + security_inode_getsecid(inode, &lsmdata); + rc = ima_filter_rule_match(&lsmdata, + rule->lsm[i].type, Audit_equal, rule->lsm[i].rule, rule->lsm[i].rules_lsm); @@ -657,7 +658,7 @@ static bool ima_match_rules(struct ima_rule_entry *rule, case LSM_SUBJ_USER: case LSM_SUBJ_ROLE: case LSM_SUBJ_TYPE: - rc = ima_filter_rule_match(lsmblob_first(blob), + rc = ima_filter_rule_match(blob, rule->lsm[i].type, Audit_equal, rule->lsm[i].rule, diff --git a/security/security.c b/security/security.c index 8bfece0911aa..563452000729 100644 --- a/security/security.c +++ b/security/security.c @@ -1579,9 +1579,16 @@ int security_inode_listsecurity(struct inode *inode, char *buffer, size_t buffer } EXPORT_SYMBOL(security_inode_listsecurity); -void security_inode_getsecid(struct inode *inode, u32 *secid) +void security_inode_getsecid(struct inode *inode, struct lsmblob *blob) { - call_void_hook(inode_getsecid, inode, secid); + struct security_hook_list *hp; + + lsmblob_init(blob, 0); + hlist_for_each_entry(hp, &security_hook_heads.inode_getsecid, list) { + if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >= lsm_slot)) + continue; + hp->hook.inode_getsecid(inode, &blob->secid[hp->lsmid->slot]); + } } int security_inode_copy_up(struct dentry *src, struct cred **new) @@ -2827,15 +2834,15 @@ void ima_filter_rule_free(void *lsmrule, int lsmslot) } } -int ima_filter_rule_match(u32 secid, u32 field, u32 op, void *lsmrule, - int lsmslot) +int ima_filter_rule_match(struct lsmblob *blob, u32 field, u32 op, + void *lsmrule, int lsmslot) { struct security_hook_list *hp; hlist_for_each_entry(hp, &security_hook_heads.audit_rule_match, list) if (hp->lsmid->slot == lsmslot) - return hp->hook.audit_rule_match(secid, field, op, - lsmrule); + return hp->hook.audit_rule_match(blob->secid[lsmslot], + field, op, lsmrule); return 0; } -- 2.37.3

Create two new prctl() options PR_LSM_ATTR_SET and PR_LSM_ATTR_GET which change and report the Interface LSM respectively. The LSM ID number of an active LSM that supplies hooks for human readable data may be passed in the arg2 value with the PR_LSM_ATTR_SET option. The PR_LSM_ATT_GET option returns the LSM ID currently in use. At this point there can only be one LSM capable of display active. A helper function lsm_task_ilsm() is provided to get the interface lsm slot for a task_struct. Security modules that wish to restrict this action may provide a task_prctl hook to do so. Each such security module is responsible for defining its policy. AppArmor hook initially provided by John Johansen <john.johansen(a)canonical.com&gt;. SELinux hook initially provided by Stephen Smalley <stephen.smalley.work(a)gmail.com&gt; Signed-off-by: Casey Schaufler <casey(a)schaufler-ca.com&gt; --- include/linux/security.h | 17 ++++ include/uapi/linux/prctl.h | 4 + security/apparmor/include/apparmor.h | 3 +- security/apparmor/lsm.c | 42 +++++++++ security/security.c | 127 +++++++++++++++++++++++---- security/selinux/hooks.c | 21 +++++ security/selinux/include/classmap.h | 3 +- 7 files changed, 198 insertions(+), 19 deletions(-) diff --git a/include/linux/security.h b/include/linux/security.h index 9f80b685542d..8d3b875cd04a 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -257,6 +257,23 @@ static inline u32 lsmblob_first(const struct lsmblob *blob) #endif } +/** + * lsm_task_ilsm - the "interface_lsm" for this task + * @task: The task to report on + * + * Returns the task's interface LSM slot. + */ +static inline int lsm_task_ilsm(struct task_struct *task) +{ +#ifdef CONFIG_SECURITY + int *ilsm = task->security; + + if (ilsm) + return *ilsm; +#endif + return LSMBLOB_INVALID; +} + /* These functions are in security/commoncap.c */ extern int cap_capable(const struct cred *cred, struct user_namespace *ns, int cap, unsigned int opts); diff --git a/include/uapi/linux/prctl.h b/include/uapi/linux/prctl.h index a5e06dcbba13..531c6e8d2d18 100644 --- a/include/uapi/linux/prctl.h +++ b/include/uapi/linux/prctl.h @@ -281,6 +281,10 @@ struct prctl_mm_map { # define PR_SME_VL_LEN_MASK 0xffff # define PR_SME_VL_INHERIT (1 << 17) /* inherit across exec */ +/* Set/get the active security module for /proc/self/attr */ +#define PR_LSM_ATTR_SET 65 /* Set the display LSM ID */ +#define PR_LSM_ATTR_GET 66 /* Get the display LSM ID */ + #define PR_SET_VMA 0x53564d41 # define PR_SET_VMA_ANON_NAME 0 diff --git a/security/apparmor/include/apparmor.h b/security/apparmor/include/apparmor.h index 9c3fc36a0702..c9e08102c96f 100644 --- a/security/apparmor/include/apparmor.h +++ b/security/apparmor/include/apparmor.h @@ -28,8 +28,9 @@ #define AA_CLASS_SIGNAL 10 #define AA_CLASS_NET 14 #define AA_CLASS_LABEL 16 +#define AA_CLASS_DISPLAY_LSM 17 -#define AA_CLASS_LAST AA_CLASS_LABEL +#define AA_CLASS_LAST AA_CLASS_DISPLAY_LSM /* Control parameters settable through module/boot flags */ extern enum audit_mode aa_g_audit; diff --git a/security/apparmor/lsm.c b/security/apparmor/lsm.c index 25423a3aa572..f47134da6723 100644 --- a/security/apparmor/lsm.c +++ b/security/apparmor/lsm.c @@ -15,6 +15,7 @@ #include <linux/mount.h> #include <linux/namei.h> #include <linux/ptrace.h> +#include <linux/prctl.h> #include <linux/ctype.h> #include <linux/sysctl.h> #include <linux/audit.h> @@ -642,6 +643,46 @@ static int apparmor_getprocattr(struct task_struct *task, char *name, return error; } + +static int profile_interface_lsm(struct aa_profile *profile, + struct common_audit_data *sa) +{ + struct aa_perms perms = { }; + unsigned int state; + + state = PROFILE_MEDIATES(profile, AA_CLASS_DISPLAY_LSM); + if (state) { + aa_compute_perms(profile->policy.dfa, state, &perms); + aa_apply_modes_to_perms(profile, &perms); + aad(sa)->label = &profile->label; + + return aa_check_perms(profile, &perms, AA_MAY_WRITE, sa, NULL); + } + + return 0; +} + +static int apparmor_task_prctl(int option, unsigned long arg2, + unsigned long arg3, unsigned long arg4, + unsigned long arg5) +{ + struct aa_profile *profile; + struct aa_label *label; + int error; + DEFINE_AUDIT_DATA(sa, LSM_AUDIT_DATA_NONE, OP_SETPROCATTR); + + if (option != PR_LSM_ATTR_SET) + return -ENOSYS; + + /* LSM infrastructure does actual setting of interface_lsm if allowed */ + aad(&sa)->info = "set interface lsm"; + label = begin_current_label_crit_section(); + error = fn_for_each_confined(label, profile, + profile_interface_lsm(profile, &sa)); + end_current_label_crit_section(label); + return error; +} + static int apparmor_setprocattr(const char *name, void *value, size_t size) { @@ -1196,6 +1237,7 @@ static struct lsm_id apparmor_lsmid __lsm_ro_after_init = { static struct security_hook_list apparmor_hooks[] __lsm_ro_after_init = { LSM_HOOK_INIT(ptrace_access_check, apparmor_ptrace_access_check), LSM_HOOK_INIT(ptrace_traceme, apparmor_ptrace_traceme), + LSM_HOOK_INIT(task_prctl, apparmor_task_prctl), LSM_HOOK_INIT(capget, apparmor_capget), LSM_HOOK_INIT(capable, apparmor_capable), diff --git a/security/security.c b/security/security.c index 80133d6e982c..43d2431dbda0 100644 --- a/security/security.c +++ b/security/security.c @@ -28,6 +28,7 @@ #include <linux/backing-dev.h> #include <linux/string.h> #include <linux/msg.h> +#include <linux/prctl.h> #include <uapi/linux/lsm.h> #include <net/flow.h> #include <net/sock.h> @@ -81,7 +82,16 @@ static struct kmem_cache *lsm_file_cache; static struct kmem_cache *lsm_inode_cache; char *lsm_names; -static struct lsm_blob_sizes blob_sizes __lsm_ro_after_init; + +/* + * The task blob includes the "interface_lsm" slot used for + * chosing which module presents contexts. + * Using a long to avoid potential alignment issues with + * module assigned task blobs. + */ +static struct lsm_blob_sizes blob_sizes __lsm_ro_after_init = { + .lbs_task = sizeof(long), +}; /* Boot-time LSM user choice */ static __initdata const char *chosen_lsm_order; @@ -691,6 +701,8 @@ int lsm_inode_alloc(struct inode *inode) */ static int lsm_task_alloc(struct task_struct *task) { + int *ilsm; + if (blob_sizes.lbs_task == 0) { task->security = NULL; return 0; @@ -699,6 +711,15 @@ static int lsm_task_alloc(struct task_struct *task) task->security = kzalloc(blob_sizes.lbs_task, GFP_KERNEL); if (task->security == NULL) return -ENOMEM; + + /* + * The start of the task blob contains the "interface" LSM slot number. + * Start with it set to the invalid slot number, indicating that the + * default first registered LSM be displayed. + */ + ilsm = task->security; + *ilsm = LSMBLOB_INVALID; + return 0; } @@ -1765,14 +1786,26 @@ int security_file_open(struct file *file) int security_task_alloc(struct task_struct *task, unsigned long clone_flags) { + int *oilsm = current->security; + int *nilsm; int rc = lsm_task_alloc(task); - if (rc) + if (unlikely(rc)) return rc; + rc = call_int_hook(task_alloc, 0, task, clone_flags); - if (unlikely(rc)) + if (unlikely(rc)) { security_task_free(task); - return rc; + return rc; + } + + if (oilsm) { + nilsm = task->security; + if (nilsm) + *nilsm = *oilsm; + } + + return 0; } void security_task_free(struct task_struct *task) @@ -2031,10 +2064,15 @@ int security_task_kill(struct task_struct *p, struct kernel_siginfo *info, int security_task_prctl(int option, unsigned long arg2, unsigned long arg3, unsigned long arg4, unsigned long arg5) { + int *ilsm = current->security; int thisrc; + int slot; int rc = LSM_RET_DEFAULT(task_prctl); struct security_hook_list *hp; + if (lsm_slot == 0) + return -EINVAL; + hlist_for_each_entry(hp, &security_hook_heads.task_prctl, list) { thisrc = hp->hook.task_prctl(option, arg2, arg3, arg4, arg5); if (thisrc != LSM_RET_DEFAULT(task_prctl)) { @@ -2043,6 +2081,25 @@ int security_task_prctl(int option, unsigned long arg2, unsigned long arg3, break; } } + + switch (option) { + case PR_LSM_ATTR_SET: + if (rc && rc != LSM_RET_DEFAULT(task_prctl)) + return rc; + for (slot = 0; slot < lsm_slot; slot++) + if (lsm_slotlist[slot]->id == arg2) { + *ilsm = lsm_slotlist[slot]->slot; + return 0; + } + return -EINVAL; + case PR_LSM_ATTR_GET: + if (rc && rc != LSM_RET_DEFAULT(task_prctl)) + return rc; + if (*ilsm != LSMBLOB_INVALID) + return lsm_slotlist[*ilsm]->id; + return lsm_slotlist[0]->id; + } + return rc; } @@ -2209,22 +2266,45 @@ int security_getprocattr(struct task_struct *p, int lsmid, char *name, char **value) { struct security_hook_list *hp; + int ilsm = lsm_task_ilsm(current); hlist_for_each_entry(hp, &security_hook_heads.getprocattr, list) { if (lsmid != LSM_ID_INVALID && lsmid != hp->lsmid->id) continue; + if (lsmid == LSM_ID_INVALID && ilsm != LSMBLOB_INVALID && + ilsm != hp->lsmid->slot) + continue; + return hp->hook.getprocattr(p, name, value); } return LSM_RET_DEFAULT(getprocattr); } +/** + * security_setprocattr - Set process attributes via /proc + * @lsmid: LSM ID of module involved + * @name: name of the attribute + * @value: value to set the attribute to + * @size: size of the value + * + * Set the process attribute for the specified security module + * to the specified value. Note that this can only be used to set + * the process attributes for the current, or "self" process. + * The /proc code has already done this check. + * + * Returns 0 on success, an appropriate code otherwise. + */ int security_setprocattr(int lsmid, const char *name, void *value, size_t size) { struct security_hook_list *hp; + int ilsm = lsm_task_ilsm(current); hlist_for_each_entry(hp, &security_hook_heads.setprocattr, list) { if (lsmid != LSM_ID_INVALID && lsmid != hp->lsmid->id) continue; + if (lsmid == LSM_ID_INVALID && ilsm != LSMBLOB_INVALID && + ilsm != hp->lsmid->slot) + continue; return hp->hook.setprocattr(name, value, size); } return LSM_RET_DEFAULT(setprocattr); @@ -2244,15 +2324,15 @@ EXPORT_SYMBOL(security_ismaclabel); int security_secid_to_secctx(struct lsmblob *blob, char **secdata, u32 *seclen) { struct security_hook_list *hp; - int rc; + int ilsm = lsm_task_ilsm(current); hlist_for_each_entry(hp, &security_hook_heads.secid_to_secctx, list) { if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >= lsm_slot)) continue; - rc = hp->hook.secid_to_secctx(blob->secid[hp->lsmid->slot], - secdata, seclen); - if (rc != LSM_RET_DEFAULT(secid_to_secctx)) - return rc; + if (ilsm == LSMBLOB_INVALID || ilsm == hp->lsmid->slot) + return hp->hook.secid_to_secctx( + blob->secid[hp->lsmid->slot], + secdata, seclen); } return LSM_RET_DEFAULT(secid_to_secctx); @@ -2263,16 +2343,15 @@ int security_secctx_to_secid(const char *secdata, u32 seclen, struct lsmblob *blob) { struct security_hook_list *hp; - int rc; + int ilsm = lsm_task_ilsm(current); lsmblob_init(blob, 0); hlist_for_each_entry(hp, &security_hook_heads.secctx_to_secid, list) { if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >= lsm_slot)) continue; - rc = hp->hook.secctx_to_secid(secdata, seclen, - &blob->secid[hp->lsmid->slot]); - if (rc != 0) - return rc; + if (ilsm == LSMBLOB_INVALID || ilsm == hp->lsmid->slot) + return hp->hook.secctx_to_secid(secdata, seclen, + &blob->secid[hp->lsmid->slot]); } return 0; } @@ -2280,7 +2359,14 @@ EXPORT_SYMBOL(security_secctx_to_secid); void security_release_secctx(char *secdata, u32 seclen) { - call_void_hook(release_secctx, secdata, seclen); + struct security_hook_list *hp; + int ilsm = lsm_task_ilsm(current); + + hlist_for_each_entry(hp, &security_hook_heads.release_secctx, list) + if (ilsm == LSMBLOB_INVALID || ilsm == hp->lsmid->slot) { + hp->hook.release_secctx(secdata, seclen); + return; + } } EXPORT_SYMBOL(security_release_secctx); @@ -2421,8 +2507,15 @@ EXPORT_SYMBOL(security_sock_rcv_skb); int security_socket_getpeersec_stream(struct socket *sock, char __user *optval, int __user *optlen, unsigned len) { - return call_int_hook(socket_getpeersec_stream, -ENOPROTOOPT, sock, - optval, optlen, len); + int ilsm = lsm_task_ilsm(current); + struct security_hook_list *hp; + + hlist_for_each_entry(hp, &security_hook_heads.socket_getpeersec_stream, + list) + if (ilsm == LSMBLOB_INVALID || ilsm == hp->lsmid->slot) + return hp->hook.socket_getpeersec_stream(sock, optval, + optlen, len); + return -ENOPROTOOPT; } int security_socket_getpeersec_dgram(struct socket *sock, struct sk_buff *skb, diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index cf89ccaa018d..aad795306bd2 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -92,6 +92,7 @@ #include <linux/fsnotify.h> #include <linux/fanotify.h> #include <linux/io_uring.h> +#include <linux/prctl.h> #include <uapi/linux/lsm.h> #include "avc.h" @@ -6373,6 +6374,24 @@ static int selinux_getprocattr(struct task_struct *p, return error; } +static int selinux_task_prctl(int option, unsigned long arg2, + unsigned long arg3, unsigned long arg4, + unsigned long arg5) +{ + u32 mysid = current_sid(); + + if (option != PR_LSM_ATTR_SET) + return -ENOSYS; + + /* + * For setting interface_lsm, we only perform a permission check; + * the actual update to the interface_lsm value is handled by the + * LSM framework. + */ + return avc_has_perm(&selinux_state, mysid, mysid, SECCLASS_PROCESS2, + PROCESS2__SETINTERFACE_LSM, NULL); +} + static int selinux_setprocattr(const char *name, void *value, size_t size) { struct task_security_struct *tsec; @@ -6384,6 +6403,7 @@ static int selinux_setprocattr(const char *name, void *value, size_t size) /* * Basic control over ability to set these attributes at all. */ + if (!strcmp(name, "exec")) error = avc_has_perm(&selinux_state, mysid, mysid, SECCLASS_PROCESS, @@ -7040,6 +7060,7 @@ static struct security_hook_list selinux_hooks[] __lsm_ro_after_init = { LSM_HOOK_INIT(ptrace_access_check, selinux_ptrace_access_check), LSM_HOOK_INIT(ptrace_traceme, selinux_ptrace_traceme), + LSM_HOOK_INIT(task_prctl, selinux_task_prctl), LSM_HOOK_INIT(capget, selinux_capget), LSM_HOOK_INIT(capset, selinux_capset), LSM_HOOK_INIT(capable, selinux_capable), diff --git a/security/selinux/include/classmap.h b/security/selinux/include/classmap.h index 1c2f41ff4e55..6b8569347bc0 100644 --- a/security/selinux/include/classmap.h +++ b/security/selinux/include/classmap.h @@ -53,7 +53,8 @@ const struct security_class_mapping secclass_map[] = { "execmem", "execstack", "execheap", "setkeycreate", "setsockcreate", "getrlimit", NULL } }, { "process2", - { "nnp_transition", "nosuid_transition", NULL } }, + { "nnp_transition", "nosuid_transition", "setinterface_lsm", + NULL } }, { "system", { "ipc_info", "syslog_read", "syslog_mod", "syslog_console", "module_request", "module_load", NULL } }, -- 2.37.3

Add a new lsmcontext data structure to hold all the information about a "security context", including the string, its size and which LSM allocated the string. The allocation information is necessary because LSMs have different policies regarding the lifecycle of these strings. SELinux allocates and destroys them on each use, whereas Smack provides a pointer to an entry in a list that never goes away. Reviewed-by: Kees Cook <keescook(a)chromium.org&gt; Reviewed-by: John Johansen <john.johansen(a)canonical.com&gt; Acked-by: Paul Moore <paul(a)paul-moore.com&gt; Acked-by: Stephen Smalley <stephen.smalley.work(a)gmail.com&gt; Acked-by: Chuck Lever <chuck.lever(a)oracle.com&gt; Signed-off-by: Casey Schaufler <casey(a)schaufler-ca.com&gt; Cc: linux-integrity(a)vger.kernel.org Cc: netdev(a)vger.kernel.org Cc: linux-audit(a)redhat.com Cc: netfilter-devel(a)vger.kernel.org To: Pablo Neira Ayuso <pablo(a)netfilter.org&gt; Cc: linux-nfs(a)vger.kernel.org --- drivers/android/binder.c | 10 ++++--- fs/ceph/xattr.c | 6 ++++- fs/nfs/nfs4proc.c | 8 ++++-- fs/nfsd/nfs4xdr.c | 7 +++-- include/linux/security.h | 35 +++++++++++++++++++++++-- include/net/scm.h | 5 +++- kernel/audit.c | 14 +++++++--- kernel/auditsc.c | 12 ++++++--- net/ipv4/ip_sockglue.c | 4 ++- net/netfilter/nf_conntrack_netlink.c | 4 ++- net/netfilter/nf_conntrack_standalone.c | 4 ++- net/netfilter/nfnetlink_queue.c | 13 ++++++--- net/netlabel/netlabel_unlabeled.c | 19 +++++++++++--- net/netlabel/netlabel_user.c | 4 ++- security/security.c | 11 ++++---- 15 files changed, 121 insertions(+), 35 deletions(-) diff --git a/drivers/android/binder.c b/drivers/android/binder.c index 6e1e35de1fcb..12aa3bea59ee 100644 --- a/drivers/android/binder.c +++ b/drivers/android/binder.c @@ -2898,6 +2898,7 @@ static void binder_transaction(struct binder_proc *proc, int t_debug_id = atomic_inc_return(&binder_last_id); char *secctx = NULL; u32 secctx_sz = 0; + struct lsmcontext scaff; /* scaffolding */ struct list_head sgc_head; struct list_head pf_head; const void __user *user_buffer = (const void __user *) @@ -3231,7 +3232,8 @@ static void binder_transaction(struct binder_proc *proc, t->security_ctx = 0; WARN_ON(1); } - security_release_secctx(secctx, secctx_sz); + lsmcontext_init(&scaff, secctx, secctx_sz, 0); + security_release_secctx(&scaff); secctx = NULL; } t->buffer->debug_id = t->debug_id; @@ -3647,8 +3649,10 @@ static void binder_transaction(struct binder_proc *proc, binder_alloc_free_buf(&target_proc->alloc, t->buffer); err_binder_alloc_buf_failed: err_bad_extra_size: - if (secctx) - security_release_secctx(secctx, secctx_sz); + if (secctx) { + lsmcontext_init(&scaff, secctx, secctx_sz, 0); + security_release_secctx(&scaff); + } err_get_secctx_failed: kfree(tcomplete); binder_stats_deleted(BINDER_STAT_TRANSACTION_COMPLETE); diff --git a/fs/ceph/xattr.c b/fs/ceph/xattr.c index f31350cda960..d943be72dfff 100644 --- a/fs/ceph/xattr.c +++ b/fs/ceph/xattr.c @@ -1395,12 +1395,16 @@ int ceph_security_init_secctx(struct dentry *dentry, umode_t mode, void ceph_release_acl_sec_ctx(struct ceph_acl_sec_ctx *as_ctx) { +#ifdef CONFIG_CEPH_FS_SECURITY_LABEL + struct lsmcontext scaff; /* scaffolding */ +#endif #ifdef CONFIG_CEPH_FS_POSIX_ACL posix_acl_release(as_ctx->acl); posix_acl_release(as_ctx->default_acl); #endif #ifdef CONFIG_CEPH_FS_SECURITY_LABEL - security_release_secctx(as_ctx->sec_ctx, as_ctx->sec_ctxlen); + lsmcontext_init(&scaff, as_ctx->sec_ctx, as_ctx->sec_ctxlen, 0); + security_release_secctx(&scaff); #endif if (as_ctx->pagelist) ceph_pagelist_release(as_ctx->pagelist); diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c index 3ed14a2a84a4..47259990fae1 100644 --- a/fs/nfs/nfs4proc.c +++ b/fs/nfs/nfs4proc.c @@ -133,8 +133,12 @@ nfs4_label_init_security(struct inode *dir, struct dentry *dentry, static inline void nfs4_label_release_security(struct nfs4_label *label) { - if (label) - security_release_secctx(label->label, label->len); + struct lsmcontext scaff; /* scaffolding */ + + if (label) { + lsmcontext_init(&scaff, label->label, label->len, 0); + security_release_secctx(&scaff); + } } static inline u32 *nfs4_bitmask(struct nfs_server *server, struct nfs4_label *label) { diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c index 1e9690a061ec..4a96e06f4827 100644 --- a/fs/nfsd/nfs4xdr.c +++ b/fs/nfsd/nfs4xdr.c @@ -2848,6 +2848,7 @@ nfsd4_encode_fattr(struct xdr_stream *xdr, struct svc_fh *fhp, int err; struct nfs4_acl *acl = NULL; #ifdef CONFIG_NFSD_V4_SECURITY_LABEL + struct lsmcontext scaff; /* scaffolding */ void *context = NULL; int contextlen; #endif @@ -3357,8 +3358,10 @@ nfsd4_encode_fattr(struct xdr_stream *xdr, struct svc_fh *fhp, out: #ifdef CONFIG_NFSD_V4_SECURITY_LABEL - if (context) - security_release_secctx(context, contextlen); + if (context) { + lsmcontext_init(&scaff, context, contextlen, 0); /*scaffolding*/ + security_release_secctx(&scaff); + } #endif /* CONFIG_NFSD_V4_SECURITY_LABEL */ kfree(acl); if (tempfh) { diff --git a/include/linux/security.h b/include/linux/security.h index 8d3b875cd04a..a3c11934620a 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -154,6 +154,37 @@ extern const char *const lockdown_reasons[LOCKDOWN_CONFIDENTIALITY_MAX+1]; extern int lsm_id; extern struct lsm_id *lsm_idlist[]; +/* + * A "security context" is the text representation of + * the information used by LSMs. + * This structure contains the string, its length, and which LSM + * it is useful for. + */ +struct lsmcontext { + char *context; /* Provided by the module */ + u32 len; + int slot; /* Identifies the module */ +}; + +/** + * lsmcontext_init - initialize an lsmcontext structure. + * @cp: Pointer to the context to initialize + * @context: Initial context, or NULL + * @size: Size of context, or 0 + * @slot: Which LSM provided the context + * + * Fill in the lsmcontext from the provided information. + * This is a scaffolding function that will be removed when + * lsmcontext integration is complete. + */ +static inline void lsmcontext_init(struct lsmcontext *cp, char *context, + u32 size, int slot) +{ + cp->slot = slot; + cp->context = context; + cp->len = size; +} + /* * Data exported by the security modules * @@ -607,7 +638,7 @@ int security_ismaclabel(const char *name); int security_secid_to_secctx(struct lsmblob *blob, char **secdata, u32 *seclen); int security_secctx_to_secid(const char *secdata, u32 seclen, struct lsmblob *blob); -void security_release_secctx(char *secdata, u32 seclen); +void security_release_secctx(struct lsmcontext *cp); void security_inode_invalidate_secctx(struct inode *inode); int security_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen); int security_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen); @@ -1478,7 +1509,7 @@ static inline int security_secctx_to_secid(const char *secdata, return -EOPNOTSUPP; } -static inline void security_release_secctx(char *secdata, u32 seclen) +static inline void security_release_secctx(struct lsmcontext *cp) { } diff --git a/include/net/scm.h b/include/net/scm.h index 23a35ff1b3f2..f273c4d777ec 100644 --- a/include/net/scm.h +++ b/include/net/scm.h @@ -92,6 +92,7 @@ static __inline__ int scm_send(struct socket *sock, struct msghdr *msg, #ifdef CONFIG_SECURITY_NETWORK static inline void scm_passec(struct socket *sock, struct msghdr *msg, struct scm_cookie *scm) { + struct lsmcontext context; struct lsmblob lb; char *secdata; u32 seclen; @@ -106,7 +107,9 @@ static inline void scm_passec(struct socket *sock, struct msghdr *msg, struct sc if (!err) { put_cmsg(msg, SOL_SOCKET, SCM_SECURITY, seclen, secdata); - security_release_secctx(secdata, seclen); + /*scaffolding*/ + lsmcontext_init(&context, secdata, seclen, 0); + security_release_secctx(&context); } } } diff --git a/kernel/audit.c b/kernel/audit.c index 3d026013e6eb..d14e54098b9c 100644 --- a/kernel/audit.c +++ b/kernel/audit.c @@ -1214,6 +1214,7 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh) struct audit_sig_info *sig_data; char *ctx = NULL; u32 len; + struct lsmcontext scaff; /* scaffolding */ err = audit_netlink_ok(skb, msg_type); if (err) @@ -1471,15 +1472,18 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh) } sig_data = kmalloc(struct_size(sig_data, ctx, len), GFP_KERNEL); if (!sig_data) { - if (lsmblob_is_set(&audit_sig_lsm)) - security_release_secctx(ctx, len); + if (lsmblob_is_set(&audit_sig_lsm)) { + lsmcontext_init(&scaff, ctx, len, 0); + security_release_secctx(&scaff); + } return -ENOMEM; } sig_data->uid = from_kuid(&init_user_ns, audit_sig_uid); sig_data->pid = audit_sig_pid; if (lsmblob_is_set(&audit_sig_lsm)) { memcpy(sig_data->ctx, ctx, len); - security_release_secctx(ctx, len); + lsmcontext_init(&scaff, ctx, len, 0); + security_release_secctx(&scaff); } audit_send_reply(skb, seq, AUDIT_SIGNAL_INFO, 0, 0, sig_data, struct_size(sig_data, ctx, len)); @@ -2171,6 +2175,7 @@ int audit_log_task_context(struct audit_buffer *ab) unsigned len; int error; struct lsmblob blob; + struct lsmcontext scaff; /* scaffolding */ security_current_getsecid_subj(&blob); if (!lsmblob_is_set(&blob)) @@ -2185,7 +2190,8 @@ int audit_log_task_context(struct audit_buffer *ab) } audit_log_format(ab, " subj=%s", ctx); - security_release_secctx(ctx, len); + lsmcontext_init(&scaff, ctx, len, 0); + security_release_secctx(&scaff); return 0; error_path: diff --git a/kernel/auditsc.c b/kernel/auditsc.c index 092aba46a9b3..8a16ed2f7206 100644 --- a/kernel/auditsc.c +++ b/kernel/auditsc.c @@ -1096,6 +1096,7 @@ static int audit_log_pid_context(struct audit_context *context, pid_t pid, struct lsmblob *blob, char *comm) { struct audit_buffer *ab; + struct lsmcontext lsmcxt; char *ctx = NULL; u32 len; int rc = 0; @@ -1113,7 +1114,8 @@ static int audit_log_pid_context(struct audit_context *context, pid_t pid, rc = 1; } else { audit_log_format(ab, " obj=%s", ctx); - security_release_secctx(ctx, len); + lsmcontext_init(&lsmcxt, ctx, len, 0); /*scaffolding*/ + security_release_secctx(&lsmcxt); } } audit_log_format(ab, " ocomm="); @@ -1373,6 +1375,7 @@ static void audit_log_time(struct audit_context *context, struct audit_buffer ** static void show_special(struct audit_context *context, int *call_panic) { + struct lsmcontext lsmcxt; struct audit_buffer *ab; int i; @@ -1407,7 +1410,8 @@ static void show_special(struct audit_context *context, int *call_panic) *call_panic = 1; } else { audit_log_format(ab, " obj=%s", ctx); - security_release_secctx(ctx, len); + lsmcontext_init(&lsmcxt, ctx, len, 0); + security_release_secctx(&lsmcxt); } } if (context->ipc.has_perm) { @@ -1569,6 +1573,7 @@ static void audit_log_name(struct audit_context *context, struct audit_names *n, char *ctx = NULL; u32 len; struct lsmblob blob; + struct lsmcontext lsmcxt; lsmblob_init(&blob, n->osid); if (security_secid_to_secctx(&blob, &ctx, &len)) { @@ -1577,7 +1582,8 @@ static void audit_log_name(struct audit_context *context, struct audit_names *n, *call_panic = 2; } else { audit_log_format(ab, " obj=%s", ctx); - security_release_secctx(ctx, len); + lsmcontext_init(&lsmcxt, ctx, len, 0); /* scaffolding */ + security_release_secctx(&lsmcxt); } } diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c index bb8e2af31d4f..030b8c3ffae0 100644 --- a/net/ipv4/ip_sockglue.c +++ b/net/ipv4/ip_sockglue.c @@ -130,6 +130,7 @@ static void ip_cmsg_recv_checksum(struct msghdr *msg, struct sk_buff *skb, static void ip_cmsg_recv_security(struct msghdr *msg, struct sk_buff *skb) { + struct lsmcontext context; struct lsmblob lb; char *secdata; u32 seclen, secid; @@ -145,7 +146,8 @@ static void ip_cmsg_recv_security(struct msghdr *msg, struct sk_buff *skb) return; put_cmsg(msg, SOL_IP, SCM_SECURITY, seclen, secdata); - security_release_secctx(secdata, seclen); + lsmcontext_init(&context, secdata, seclen, 0); /* scaffolding */ + security_release_secctx(&context); } static void ip_cmsg_recv_dstaddr(struct msghdr *msg, struct sk_buff *skb) diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c index 2e257aa4f61b..2bf2673042f4 100644 --- a/net/netfilter/nf_conntrack_netlink.c +++ b/net/netfilter/nf_conntrack_netlink.c @@ -348,6 +348,7 @@ static int ctnetlink_dump_secctx(struct sk_buff *skb, const struct nf_conn *ct) int len, ret; char *secctx; struct lsmblob blob; + struct lsmcontext context; /* lsmblob_init() puts ct->secmark into all of the secids in blob. * security_secid_to_secctx() will know which security module @@ -368,7 +369,8 @@ static int ctnetlink_dump_secctx(struct sk_buff *skb, const struct nf_conn *ct) ret = 0; nla_put_failure: - security_release_secctx(secctx, len); + lsmcontext_init(&context, secctx, len, 0); /* scaffolding */ + security_release_secctx(&context); return ret; } #else diff --git a/net/netfilter/nf_conntrack_standalone.c b/net/netfilter/nf_conntrack_standalone.c index da61eb8cde76..b0f4349ff88f 100644 --- a/net/netfilter/nf_conntrack_standalone.c +++ b/net/netfilter/nf_conntrack_standalone.c @@ -179,6 +179,7 @@ static void ct_show_secctx(struct seq_file *s, const struct nf_conn *ct) u32 len; char *secctx; struct lsmblob blob; + struct lsmcontext context; lsmblob_init(&blob, ct->secmark); ret = security_secid_to_secctx(&blob, &secctx, &len); @@ -187,7 +188,8 @@ static void ct_show_secctx(struct seq_file *s, const struct nf_conn *ct) seq_printf(s, "secctx=%s ", secctx); - security_release_secctx(secctx, len); + lsmcontext_init(&context, secctx, len, 0); /* scaffolding */ + security_release_secctx(&context); } #else static inline void ct_show_secctx(struct seq_file *s, const struct nf_conn *ct) diff --git a/net/netfilter/nfnetlink_queue.c b/net/netfilter/nfnetlink_queue.c index bc25d49575e4..1416f8b2fc83 100644 --- a/net/netfilter/nfnetlink_queue.c +++ b/net/netfilter/nfnetlink_queue.c @@ -397,6 +397,7 @@ nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue, enum ip_conntrack_info ctinfo = 0; const struct nfnl_ct_hook *nfnl_ct; bool csum_verify; + struct lsmcontext scaff; /* scaffolding */ char *secdata = NULL; u32 seclen = 0; ktime_t tstamp; @@ -634,8 +635,10 @@ nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue, } nlh->nlmsg_len = skb->len; - if (seclen) - security_release_secctx(secdata, seclen); + if (seclen) { + lsmcontext_init(&scaff, secdata, seclen, 0); + security_release_secctx(&scaff); + } return skb; nla_put_failure: @@ -643,8 +646,10 @@ nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue, kfree_skb(skb); net_err_ratelimited("nf_queue: error creating packet message\n"); nlmsg_failure: - if (seclen) - security_release_secctx(secdata, seclen); + if (seclen) { + lsmcontext_init(&scaff, secdata, seclen, 0); + security_release_secctx(&scaff); + } return NULL; } diff --git a/net/netlabel/netlabel_unlabeled.c b/net/netlabel/netlabel_unlabeled.c index 604b9d1dd085..f62b88c85976 100644 --- a/net/netlabel/netlabel_unlabeled.c +++ b/net/netlabel/netlabel_unlabeled.c @@ -374,6 +374,7 @@ int netlbl_unlhsh_add(struct net *net, struct net_device *dev; struct netlbl_unlhsh_iface *iface; struct audit_buffer *audit_buf = NULL; + struct lsmcontext context; char *secctx = NULL; u32 secctx_len; struct lsmblob blob; @@ -447,7 +448,9 @@ int netlbl_unlhsh_add(struct net *net, &secctx, &secctx_len) == 0) { audit_log_format(audit_buf, " sec_obj=%s", secctx); - security_release_secctx(secctx, secctx_len); + /* scaffolding */ + lsmcontext_init(&context, secctx, secctx_len, 0); + security_release_secctx(&context); } audit_log_format(audit_buf, " res=%u", ret_val == 0 ? 1 : 0); audit_log_end(audit_buf); @@ -478,6 +481,7 @@ static int netlbl_unlhsh_remove_addr4(struct net *net, struct netlbl_unlhsh_addr4 *entry; struct audit_buffer *audit_buf; struct net_device *dev; + struct lsmcontext context; char *secctx; u32 secctx_len; struct lsmblob blob; @@ -508,7 +512,9 @@ static int netlbl_unlhsh_remove_addr4(struct net *net, security_secid_to_secctx(&blob, &secctx, &secctx_len) == 0) { audit_log_format(audit_buf, " sec_obj=%s", secctx); - security_release_secctx(secctx, secctx_len); + /* scaffolding */ + lsmcontext_init(&context, secctx, secctx_len, 0); + security_release_secctx(&context); } audit_log_format(audit_buf, " res=%u", entry != NULL ? 1 : 0); audit_log_end(audit_buf); @@ -545,6 +551,7 @@ static int netlbl_unlhsh_remove_addr6(struct net *net, struct netlbl_unlhsh_addr6 *entry; struct audit_buffer *audit_buf; struct net_device *dev; + struct lsmcontext context; char *secctx; u32 secctx_len; struct lsmblob blob; @@ -574,7 +581,8 @@ static int netlbl_unlhsh_remove_addr6(struct net *net, security_secid_to_secctx(&blob, &secctx, &secctx_len) == 0) { audit_log_format(audit_buf, " sec_obj=%s", secctx); - security_release_secctx(secctx, secctx_len); + lsmcontext_init(&context, secctx, secctx_len, 0); + security_release_secctx(&context); } audit_log_format(audit_buf, " res=%u", entry != NULL ? 1 : 0); audit_log_end(audit_buf); @@ -1093,6 +1101,7 @@ static int netlbl_unlabel_staticlist_gen(u32 cmd, int ret_val = -ENOMEM; struct netlbl_unlhsh_walk_arg *cb_arg = arg; struct net_device *dev; + struct lsmcontext context; void *data; u32 secid; char *secctx; @@ -1163,7 +1172,9 @@ static int netlbl_unlabel_staticlist_gen(u32 cmd, NLBL_UNLABEL_A_SECCTX, secctx_len, secctx); - security_release_secctx(secctx, secctx_len); + /* scaffolding */ + lsmcontext_init(&context, secctx, secctx_len, 0); + security_release_secctx(&context); if (ret_val != 0) goto list_cb_failure; diff --git a/net/netlabel/netlabel_user.c b/net/netlabel/netlabel_user.c index 893301ae0131..ef139d8ae7cd 100644 --- a/net/netlabel/netlabel_user.c +++ b/net/netlabel/netlabel_user.c @@ -84,6 +84,7 @@ struct audit_buffer *netlbl_audit_start_common(int type, struct netlbl_audit *audit_info) { struct audit_buffer *audit_buf; + struct lsmcontext context; char *secctx; u32 secctx_len; struct lsmblob blob; @@ -103,7 +104,8 @@ struct audit_buffer *netlbl_audit_start_common(int type, if (audit_info->secid != 0 && security_secid_to_secctx(&blob, &secctx, &secctx_len) == 0) { audit_log_format(audit_buf, " subj=%s", secctx); - security_release_secctx(secctx, secctx_len); + lsmcontext_init(&context, secctx, secctx_len, 0);/*scaffolding*/ + security_release_secctx(&context); } return audit_buf; diff --git a/security/security.c b/security/security.c index 43d2431dbda0..44312b3437da 100644 --- a/security/security.c +++ b/security/security.c @@ -2357,16 +2357,17 @@ int security_secctx_to_secid(const char *secdata, u32 seclen, } EXPORT_SYMBOL(security_secctx_to_secid); -void security_release_secctx(char *secdata, u32 seclen) +void security_release_secctx(struct lsmcontext *cp) { struct security_hook_list *hp; - int ilsm = lsm_task_ilsm(current); hlist_for_each_entry(hp, &security_hook_heads.release_secctx, list) - if (ilsm == LSMBLOB_INVALID || ilsm == hp->lsmid->slot) { - hp->hook.release_secctx(secdata, seclen); - return; + if (cp->slot == hp->lsmid->slot) { + hp->hook.release_secctx(cp->context, cp->len); + break; } + + memset(cp, 0, sizeof(*cp)); } EXPORT_SYMBOL(security_release_secctx); -- 2.37.3

Change the security_inode_getsecctx() interface to fill a lsmcontext structure instead of data and length pointers. This provides the information about which LSM created the context so that security_release_secctx() can use the correct hook. Acked-by: Stephen Smalley <stephen.smalley.work(a)gmail.com&gt; Acked-by: Paul Moore <paul(a)paul-moore.com&gt; Acked-by: Chuck Lever <chuck.lever(a)oracle.com&gt; Reviewed-by: Kees Cook <keescook(a)chromium.org&gt; Reviewed-by: John Johansen <john.johansen(a)canonical.com&gt; Signed-off-by: Casey Schaufler <casey(a)schaufler-ca.com&gt; Cc: linux-nfs(a)vger.kernel.org --- fs/nfsd/nfs4xdr.c | 23 +++++++++-------------- include/linux/security.h | 5 +++-- security/security.c | 13 +++++++++++-- 3 files changed, 23 insertions(+), 18 deletions(-) diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c index 4a96e06f4827..515ea278a200 100644 --- a/fs/nfsd/nfs4xdr.c +++ b/fs/nfsd/nfs4xdr.c @@ -2732,11 +2732,11 @@ nfsd4_encode_layout_types(struct xdr_stream *xdr, u32 layout_types) #ifdef CONFIG_NFSD_V4_SECURITY_LABEL static inline __be32 nfsd4_encode_security_label(struct xdr_stream *xdr, struct svc_rqst *rqstp, - void *context, int len) + struct lsmcontext *context) { __be32 *p; - p = xdr_reserve_space(xdr, len + 4 + 4 + 4); + p = xdr_reserve_space(xdr, context->len + 4 + 4 + 4); if (!p) return nfserr_resource; @@ -2746,13 +2746,13 @@ nfsd4_encode_security_label(struct xdr_stream *xdr, struct svc_rqst *rqstp, */ *p++ = cpu_to_be32(0); /* lfs */ *p++ = cpu_to_be32(0); /* pi */ - p = xdr_encode_opaque(p, context, len); + p = xdr_encode_opaque(p, context->context, context->len); return 0; } #else static inline __be32 nfsd4_encode_security_label(struct xdr_stream *xdr, struct svc_rqst *rqstp, - void *context, int len) + struct lsmcontext *context) { return 0; } #endif @@ -2848,9 +2848,7 @@ nfsd4_encode_fattr(struct xdr_stream *xdr, struct svc_fh *fhp, int err; struct nfs4_acl *acl = NULL; #ifdef CONFIG_NFSD_V4_SECURITY_LABEL - struct lsmcontext scaff; /* scaffolding */ - void *context = NULL; - int contextlen; + struct lsmcontext context = { }; #endif bool contextsupport = false; struct nfsd4_compoundres *resp = rqstp->rq_resp; @@ -2911,7 +2909,7 @@ nfsd4_encode_fattr(struct xdr_stream *xdr, struct svc_fh *fhp, bmval0 & FATTR4_WORD0_SUPPORTED_ATTRS) { if (exp->ex_flags & NFSEXP_SECURITY_LABEL) err = security_inode_getsecctx(d_inode(dentry), - &context, &contextlen); + &context); else err = -EOPNOTSUPP; contextsupport = (err == 0); @@ -3337,8 +3335,7 @@ nfsd4_encode_fattr(struct xdr_stream *xdr, struct svc_fh *fhp, #ifdef CONFIG_NFSD_V4_SECURITY_LABEL if (bmval2 & FATTR4_WORD2_SECURITY_LABEL) { - status = nfsd4_encode_security_label(xdr, rqstp, context, - contextlen); + status = nfsd4_encode_security_label(xdr, rqstp, &context); if (status) goto out; } @@ -3358,10 +3355,8 @@ nfsd4_encode_fattr(struct xdr_stream *xdr, struct svc_fh *fhp, out: #ifdef CONFIG_NFSD_V4_SECURITY_LABEL - if (context) { - lsmcontext_init(&scaff, context, contextlen, 0); /*scaffolding*/ - security_release_secctx(&scaff); - } + if (context.context) + security_release_secctx(&context); #endif /* CONFIG_NFSD_V4_SECURITY_LABEL */ kfree(acl); if (tempfh) { diff --git a/include/linux/security.h b/include/linux/security.h index bb548f71a824..be935b8d7df5 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -642,7 +642,7 @@ void security_release_secctx(struct lsmcontext *cp); void security_inode_invalidate_secctx(struct inode *inode); int security_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen); int security_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen); -int security_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen); +int security_inode_getsecctx(struct inode *inode, struct lsmcontext *cp); int security_locked_down(enum lockdown_reason what); #else /* CONFIG_SECURITY */ @@ -1525,7 +1525,8 @@ static inline int security_inode_setsecctx(struct dentry *dentry, void *ctx, u32 { return -EOPNOTSUPP; } -static inline int security_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen) +static inline int security_inode_getsecctx(struct inode *inode, + struct lsmcontext *cp) { return -EOPNOTSUPP; } diff --git a/security/security.c b/security/security.c index cae35e5767ec..d57554ce386a 100644 --- a/security/security.c +++ b/security/security.c @@ -2412,9 +2412,18 @@ int security_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen) } EXPORT_SYMBOL(security_inode_setsecctx); -int security_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen) +int security_inode_getsecctx(struct inode *inode, struct lsmcontext *cp) { - return call_int_hook(inode_getsecctx, -EOPNOTSUPP, inode, ctx, ctxlen); + struct security_hook_list *hp; + + memset(cp, 0, sizeof(*cp)); + + hlist_for_each_entry(hp, &security_hook_heads.inode_getsecctx, list) { + cp->slot = hp->lsmid->slot; + return hp->hook.inode_getsecctx(inode, (void **)&cp->context, + &cp->len); + } + return -EOPNOTSUPP; } EXPORT_SYMBOL(security_inode_getsecctx); -- 2.37.3

Change netlink netfilter interfaces to use lsmcontext pointers, and remove scaffolding. Reviewed-by: Kees Cook <keescook(a)chromium.org&gt; Reviewed-by: John Johansen <john.johansen(a)canonical.com&gt; Acked-by: Paul Moore <paul(a)paul-moore.com&gt; Acked-by: Stephen Smalley <stephen.smalley.work(a)gmail.com&gt; Acked-by: Pablo Neira Ayuso <pablo(a)netfilter.org&gt; Signed-off-by: Casey Schaufler <casey(a)schaufler-ca.com&gt; Cc: netdev(a)vger.kernel.org Cc: netfilter-devel(a)vger.kernel.org --- net/netfilter/nfnetlink_queue.c | 37 +++++++++++++-------------------- 1 file changed, 14 insertions(+), 23 deletions(-) diff --git a/net/netfilter/nfnetlink_queue.c b/net/netfilter/nfnetlink_queue.c index 46f49cd2543d..3a7d1a693c5e 100644 --- a/net/netfilter/nfnetlink_queue.c +++ b/net/netfilter/nfnetlink_queue.c @@ -301,15 +301,13 @@ static int nfqnl_put_sk_uidgid(struct sk_buff *skb, struct sock *sk) return -1; } -static u32 nfqnl_get_sk_secctx(struct sk_buff *skb, char **secdata) +static void nfqnl_get_sk_secctx(struct sk_buff *skb, struct lsmcontext *context) { - u32 seclen = 0; #if IS_ENABLED(CONFIG_NETWORK_SECMARK) struct lsmblob blob; - struct lsmcontext context = { }; if (!skb || !sk_fullsock(skb->sk)) - return 0; + return; read_lock_bh(&skb->sk->sk_callback_lock); @@ -318,14 +316,12 @@ static u32 nfqnl_get_sk_secctx(struct sk_buff *skb, char **secdata) * blob. security_secid_to_secctx() will know which security * module to use to create the secctx. */ lsmblob_init(&blob, skb->secmark); - security_secid_to_secctx(&blob, &context); - *secdata = context.context; + security_secid_to_secctx(&blob, context); } read_unlock_bh(&skb->sk->sk_callback_lock); - seclen = context.len; #endif - return seclen; + return; } static u32 nfqnl_get_bridge_size(struct nf_queue_entry *entry) @@ -397,12 +393,10 @@ nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue, struct net_device *indev; struct net_device *outdev; struct nf_conn *ct = NULL; + struct lsmcontext context = { }; enum ip_conntrack_info ctinfo = 0; const struct nfnl_ct_hook *nfnl_ct; bool csum_verify; - struct lsmcontext scaff; /* scaffolding */ - char *secdata = NULL; - u32 seclen = 0; ktime_t tstamp; size = nlmsg_total_size(sizeof(struct nfgenmsg)) @@ -473,9 +467,9 @@ nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue, } if ((queue->flags & NFQA_CFG_F_SECCTX) && entskb->sk) { - seclen = nfqnl_get_sk_secctx(entskb, &secdata); - if (seclen) - size += nla_total_size(seclen); + nfqnl_get_sk_secctx(entskb, &context); + if (context.len) + size += nla_total_size(context.len); } skb = alloc_skb(size, GFP_ATOMIC); @@ -610,7 +604,8 @@ nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue, nfqnl_put_sk_uidgid(skb, entskb->sk) < 0) goto nla_put_failure; - if (seclen && nla_put(skb, NFQA_SECCTX, seclen, secdata)) + if (context.len && + nla_put(skb, NFQA_SECCTX, context.len, context.context)) goto nla_put_failure; if (ct && nfnl_ct->build(skb, ct, ctinfo, NFQA_CT, NFQA_CT_INFO) < 0) @@ -638,10 +633,8 @@ nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue, } nlh->nlmsg_len = skb->len; - if (seclen) { - lsmcontext_init(&scaff, secdata, seclen, 0); - security_release_secctx(&scaff); - } + if (context.len) + security_release_secctx(&context); return skb; nla_put_failure: @@ -649,10 +642,8 @@ nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue, kfree_skb(skb); net_err_ratelimited("nf_queue: error creating packet message\n"); nlmsg_failure: - if (seclen) { - lsmcontext_init(&scaff, secdata, seclen, 0); - security_release_secctx(&scaff); - } + if (context.len) + security_release_secctx(&context); return NULL; } -- 2.37.3

Send an identifier for the security module interface_lsm along with the security context. This allows the receiver to verify that the receiver and the sender agree on which security module's context is being used. If they don't agree the message is rejected. Signed-off-by: Casey Schaufler <casey(a)schaufler-ca.com&gt; --- drivers/android/binder.c | 21 +++++++++++++++++++++ drivers/android/binder_internal.h | 1 + 2 files changed, 22 insertions(+) diff --git a/drivers/android/binder.c b/drivers/android/binder.c index 5cfdaec0f9b5..ff8f35b9bd1b 100644 --- a/drivers/android/binder.c +++ b/drivers/android/binder.c @@ -3222,6 +3222,7 @@ static void binder_transaction(struct binder_proc *proc, ALIGN(extra_buffers_size, sizeof(void *)) - ALIGN(lsmctx.len, sizeof(u64)); + t->security_interface = lsm_task_ilsm(current); t->security_ctx = (uintptr_t)t->buffer->user_data + buf_offset; err = binder_alloc_copy_to_buffer(&target_proc->alloc, t->buffer, buf_offset, @@ -4667,6 +4668,26 @@ static int binder_thread_read(struct binder_proc *proc, tr.secctx = t->security_ctx; if (t->security_ctx) { + int to_ilsm = lsm_task_ilsm(current); + int from_ilsm = t->security_interface; + + if (to_ilsm == LSMBLOB_INVALID) + to_ilsm = 0; + if (from_ilsm == LSMBLOB_INVALID) + from_ilsm = 0; + /* + * The sender provided a security context from + * a different security module than the one this + * process wants to report if these don't match. + */ + if (from_ilsm != to_ilsm) { + if (t_from) + binder_thread_dec_tmpref(t_from); + + binder_cleanup_transaction(t, "security context mismatch", + BR_FAILED_REPLY); + return -EINVAL; + } cmd = BR_TRANSACTION_SEC_CTX; trsize = sizeof(tr); } diff --git a/drivers/android/binder_internal.h b/drivers/android/binder_internal.h index abe19d88c6ec..152d0b55e050 100644 --- a/drivers/android/binder_internal.h +++ b/drivers/android/binder_internal.h @@ -528,6 +528,7 @@ struct binder_transaction { long saved_priority; kuid_t sender_euid; struct list_head fd_fixups; + int security_interface; binder_uintptr_t security_ctx; /** * @lock: protects @from, @to_proc, and @to_thread -- 2.37.3

Replace the osid field in the audit_names structure with a lsmblob structure. This accommodates the use of an lsmblob in security_audit_rule_match() and security_inode_getsecid(). Signed-off-by: Casey Schaufler <casey(a)schaufler-ca.com&gt; Acked-by: Paul Moore <paul(a)paul-moore.com&gt; --- kernel/audit.h | 2 +- kernel/auditsc.c | 22 ++++++++-------------- 2 files changed, 9 insertions(+), 15 deletions(-) diff --git a/kernel/audit.h b/kernel/audit.h index 316fac62d5f7..4af63e7dde17 100644 --- a/kernel/audit.h +++ b/kernel/audit.h @@ -82,7 +82,7 @@ struct audit_names { kuid_t uid; kgid_t gid; dev_t rdev; - u32 osid; + struct lsmblob lsmblob; struct audit_cap_data fcap; unsigned int fcap_ver; unsigned char type; /* record type */ diff --git a/kernel/auditsc.c b/kernel/auditsc.c index ca00187b4864..e8f632736d2b 100644 --- a/kernel/auditsc.c +++ b/kernel/auditsc.c @@ -700,17 +700,16 @@ static int audit_filter_rules(struct task_struct *tsk, * lsmblob, which happens later in * this patch set. */ - lsmblob_init(&blob, name->osid); result = security_audit_rule_match( - &blob, + &name->lsmblob, f->type, f->op, &f->lsm_rules); } else if (ctx) { list_for_each_entry(n, &ctx->names_list, list) { - lsmblob_init(&blob, n->osid); if (security_audit_rule_match( - &blob, f->type, f->op, + &n->lsmblob, + f->type, f->op, &f->lsm_rules)) { ++result; break; @@ -1564,13 +1563,12 @@ static void audit_log_name(struct audit_context *context, struct audit_names *n, from_kgid(&init_user_ns, n->gid), MAJOR(n->rdev), MINOR(n->rdev)); - if (n->osid != 0) { - struct lsmblob blob; + if (lsmblob_is_set(&n->lsmblob)) { struct lsmcontext lsmctx; - lsmblob_init(&blob, n->osid); - if (security_secid_to_secctx(&blob, &lsmctx, LSMBLOB_FIRST)) { - audit_log_format(ab, " osid=%u", n->osid); + if (security_secid_to_secctx(&n->lsmblob, &lsmctx, + LSMBLOB_FIRST)) { + audit_log_format(ab, " osid=?"); if (call_panic) *call_panic = 2; } else { @@ -2278,17 +2276,13 @@ static void audit_copy_inode(struct audit_names *name, const struct dentry *dentry, struct inode *inode, unsigned int flags) { - struct lsmblob blob; - name->ino = inode->i_ino; name->dev = inode->i_sb->s_dev; name->mode = inode->i_mode; name->uid = inode->i_uid; name->gid = inode->i_gid; name->rdev = inode->i_rdev; - security_inode_getsecid(inode, &blob); - /* scaffolding until osid is updated */ - name->osid = lsmblob_first(&blob); + security_inode_getsecid(inode, &name->lsmblob); if (flags & AUDIT_INODE_NOEVAL) { name->fcap_ver = -1; return; -- 2.37.3

Add a new boolean function lsm_multiple_contexts() to identify when multiple security modules provide security context strings. Signed-off-by: Casey Schaufler <casey(a)schaufler-ca.com&gt; Acked-by: Paul Moore <paul(a)paul-moore.com&gt; Reviewed-by: John Johansen <john.johansen(a)canonical.com&gt; --- include/linux/security.h | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/include/linux/security.h b/include/linux/security.h index 170b303e9122..c190b9189287 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -262,6 +262,15 @@ static inline const char *lsm_slot_to_name(int slot) } #endif +static inline bool lsm_multiple_contexts(void) +{ +#ifdef CONFIG_SECURITY + return lsm_slot_to_name(1) != NULL; +#else + return false; +#endif +} + /** * lsmblob_value - find the first non-zero value in an lsmblob structure. * @blob: Pointer to the data -- 2.37.3

Create a new audit record AUDIT_MAC_TASK_CONTEXTS. An example of the MAC_TASK_CONTEXTS (1420) record is: type=MAC_TASK_CONTEXTS[1420] msg=audit(1600880931.832:113) subj_apparmor=unconfined subj_smack=_ When an audit event includes a AUDIT_MAC_TASK_CONTEXTS record the "subj=" field in other records in the event will be "subj=?". An AUDIT_MAC_TASK_CONTEXTS record is supplied when the system has multiple security modules that may make access decisions based on a subject security context. Acked-by: Paul Moore <paul(a)paul-moore.com&gt; Signed-off-by: Casey Schaufler <casey(a)schaufler-ca.com&gt; --- include/uapi/linux/audit.h | 1 + kernel/audit.c | 42 +++++++++++++++++++++++++++++++------- 2 files changed, 36 insertions(+), 7 deletions(-) diff --git a/include/uapi/linux/audit.h b/include/uapi/linux/audit.h index 7c1dc818b1d5..7a5966b46f38 100644 --- a/include/uapi/linux/audit.h +++ b/include/uapi/linux/audit.h @@ -143,6 +143,7 @@ #define AUDIT_MAC_UNLBL_STCDEL 1417 /* NetLabel: del a static label */ #define AUDIT_MAC_CALIPSO_ADD 1418 /* NetLabel: add CALIPSO DOI entry */ #define AUDIT_MAC_CALIPSO_DEL 1419 /* NetLabel: del CALIPSO DOI entry */ +#define AUDIT_MAC_TASK_CONTEXTS 1420 /* Multiple LSM task contexts */ #define AUDIT_FIRST_KERN_ANOM_MSG 1700 #define AUDIT_LAST_KERN_ANOM_MSG 1799 diff --git a/kernel/audit.c b/kernel/audit.c index ef6b2d38e38d..fb182f7e9d18 100644 --- a/kernel/audit.c +++ b/kernel/audit.c @@ -2228,6 +2228,7 @@ static void audit_buffer_aux_end(struct audit_buffer *ab) int audit_log_task_context(struct audit_buffer *ab) { + int i; int error; struct lsmblob blob; struct lsmcontext context; @@ -2236,16 +2237,43 @@ int audit_log_task_context(struct audit_buffer *ab) if (!lsmblob_is_set(&blob)) return 0; - error = security_secid_to_secctx(&blob, &context, LSMBLOB_FIRST); - - if (error) { - if (error != -EINVAL) + if (!lsm_multiple_contexts()) { + error = security_secid_to_secctx(&blob, &context, + LSMBLOB_FIRST); + if (error) { + if (error != -EINVAL) + goto error_path; + return 0; + } + audit_log_format(ab, " subj=%s", context.context); + security_release_secctx(&context); + } else { + /* Multiple LSMs provide contexts. Include an aux record. */ + audit_log_format(ab, " subj=?"); + error = audit_buffer_aux_new(ab, AUDIT_MAC_TASK_CONTEXTS); + if (error) goto error_path; - return 0; + for (i = 0; i < LSMBLOB_ENTRIES; i++) { + if (blob.secid[i] == 0) + continue; + error = security_secid_to_secctx(&blob, &context, i); + if (error) { + audit_log_format(ab, "%ssubj_%s=?", + i ? " " : "", + lsm_slot_to_name(i)); + if (error != -EINVAL) + audit_panic("error in audit_log_task_context"); + } else { + audit_log_format(ab, "%ssubj_%s=%s", + i ? " " : "", + lsm_slot_to_name(i), + context.context); + security_release_secctx(&context); + } + } + audit_buffer_aux_end(ab); } - audit_log_format(ab, " subj=%s", context.context); - security_release_secctx(&context); return 0; error_path: -- 2.37.3

Create a new audit record AUDIT_MAC_OBJ_CONTEXTS. An example of the MAC_OBJ_CONTEXTS (1421) record is: type=MAC_OBJ_CONTEXTS[1421] msg=audit(1601152467.009:1050): obj_selinux=unconfined_u:object_r:user_home_t:s0 When an audit event includes a AUDIT_MAC_OBJ_CONTEXTS record the "obj=" field in other records in the event will be "obj=?". An AUDIT_MAC_OBJ_CONTEXTS record is supplied when the system has multiple security modules that may make access decisions based on an object security context. Signed-off-by: Casey Schaufler <casey(a)schaufler-ca.com&gt; Acked-by: Paul Moore <paul(a)paul-moore.com&gt; --- include/linux/audit.h | 5 +++ include/uapi/linux/audit.h | 1 + kernel/audit.c | 49 ++++++++++++++++++++++- kernel/auditsc.c | 79 ++++++++++++-------------------------- 4 files changed, 78 insertions(+), 56 deletions(-) diff --git a/include/linux/audit.h b/include/linux/audit.h index 87ba6fe7f1a2..ce3f034e0c04 100644 --- a/include/linux/audit.h +++ b/include/linux/audit.h @@ -188,6 +188,8 @@ extern void audit_log_path_denied(int type, const char *operation); extern void audit_log_lost(const char *message); +extern void audit_log_object_context(struct audit_buffer *ab, + struct lsmblob *blob); extern int audit_log_subject_context(struct audit_buffer *ab, struct lsmblob *blob); extern int audit_log_task_context(struct audit_buffer *ab); @@ -250,6 +252,9 @@ static inline void audit_log_key(struct audit_buffer *ab, char *key) { } static inline void audit_log_path_denied(int type, const char *operation) { } +static inline void audit_log_object_context(struct audit_buffer *ab, + struct lsmblob *blob) +{ } static inline int audit_log_subject_context(struct audit_buffer *ab, struct lsmblob *blob) { diff --git a/include/uapi/linux/audit.h b/include/uapi/linux/audit.h index 7a5966b46f38..e5fae08982ca 100644 --- a/include/uapi/linux/audit.h +++ b/include/uapi/linux/audit.h @@ -144,6 +144,7 @@ #define AUDIT_MAC_CALIPSO_ADD 1418 /* NetLabel: add CALIPSO DOI entry */ #define AUDIT_MAC_CALIPSO_DEL 1419 /* NetLabel: del CALIPSO DOI entry */ #define AUDIT_MAC_TASK_CONTEXTS 1420 /* Multiple LSM task contexts */ +#define AUDIT_MAC_OBJ_CONTEXTS 1421 /* Multiple LSM objext contexts */ #define AUDIT_FIRST_KERN_ANOM_MSG 1700 #define AUDIT_LAST_KERN_ANOM_MSG 1799 diff --git a/kernel/audit.c b/kernel/audit.c index a611130f83cb..a1679bac7944 100644 --- a/kernel/audit.c +++ b/kernel/audit.c @@ -1107,7 +1107,6 @@ static int is_audit_feature_set(int i) return af.features & AUDIT_FEATURE_TO_MASK(i); } - static int audit_get_feature(struct sk_buff *skb) { u32 seq; @@ -2288,6 +2287,54 @@ int audit_log_task_context(struct audit_buffer *ab) } EXPORT_SYMBOL(audit_log_task_context); +void audit_log_object_context(struct audit_buffer *ab, struct lsmblob *blob) +{ + int i; + int error; + struct lsmcontext context; + + if (!lsm_multiple_contexts()) { + error = security_secid_to_secctx(blob, &context, LSMBLOB_FIRST); + if (error) { + if (error != -EINVAL) + goto error_path; + return; + } + audit_log_format(ab, " obj=%s", context.context); + security_release_secctx(&context); + } else { + audit_log_format(ab, " obj=?"); + error = audit_buffer_aux_new(ab, AUDIT_MAC_OBJ_CONTEXTS); + if (error) + goto error_path; + + for (i = 0; i < LSMBLOB_ENTRIES; i++) { + if (blob->secid[i] == 0) + continue; + error = security_secid_to_secctx(blob, &context, i); + if (error) { + audit_log_format(ab, "%sobj_%s=?", + i ? " " : "", + lsm_slot_to_name(i)); + if (error != -EINVAL) + audit_panic("error in audit_log_object_context"); + } else { + audit_log_format(ab, "%sobj_%s=%s", + i ? " " : "", + lsm_slot_to_name(i), + context.context); + security_release_secctx(&context); + } + } + + audit_buffer_aux_end(ab); + } + return; + +error_path: + audit_panic("error in audit_log_object_context"); +} + void audit_log_d_path_exe(struct audit_buffer *ab, struct mm_struct *mm) { diff --git a/kernel/auditsc.c b/kernel/auditsc.c index bc0621282a9a..f62605d994fa 100644 --- a/kernel/auditsc.c +++ b/kernel/auditsc.c @@ -1089,36 +1089,25 @@ static inline void audit_free_context(struct audit_context *context) kfree(context); } -static int audit_log_pid_context(struct audit_context *context, pid_t pid, - kuid_t auid, kuid_t uid, - unsigned int sessionid, - struct lsmblob *blob, char *comm) +static void audit_log_pid_context(struct audit_context *context, pid_t pid, + kuid_t auid, kuid_t uid, + unsigned int sessionid, + struct lsmblob *blob, char *comm) { struct audit_buffer *ab; - struct lsmcontext lsmctx; - int rc = 0; ab = audit_log_start(context, GFP_KERNEL, AUDIT_OBJ_PID); if (!ab) - return rc; + return; audit_log_format(ab, "opid=%d oauid=%d ouid=%d oses=%d", pid, from_kuid(&init_user_ns, auid), from_kuid(&init_user_ns, uid), sessionid); - if (lsmblob_is_set(blob)) { - if (security_secid_to_secctx(blob, &lsmctx, LSMBLOB_FIRST)) { - audit_log_format(ab, " obj=(none)"); - rc = 1; - } else { - audit_log_format(ab, " obj=%s", lsmctx.context); - security_release_secctx(&lsmctx); - } - } + if (lsmblob_is_set(blob)) + audit_log_object_context(ab, blob); audit_log_format(ab, " ocomm="); audit_log_untrustedstring(ab, comm); audit_log_end(ab); - - return rc; } static void audit_log_execve_info(struct audit_context *context, @@ -1395,18 +1384,10 @@ static void show_special(struct audit_context *context, int *call_panic) from_kgid(&init_user_ns, context->ipc.gid), context->ipc.mode); if (osid) { - struct lsmcontext lsmcxt; struct lsmblob blob; lsmblob_init(&blob, osid); - if (security_secid_to_secctx(&blob, &lsmcxt, - LSMBLOB_FIRST)) { - audit_log_format(ab, " osid=%u", osid); - *call_panic = 1; - } else { - audit_log_format(ab, " obj=%s", lsmcxt.context); - security_release_secctx(&lsmcxt); - } + audit_log_object_context(ab, &blob); } if (context->ipc.has_perm) { audit_log_end(ab); @@ -1563,19 +1544,8 @@ static void audit_log_name(struct audit_context *context, struct audit_names *n, from_kgid(&init_user_ns, n->gid), MAJOR(n->rdev), MINOR(n->rdev)); - if (lsmblob_is_set(&n->lsmblob)) { - struct lsmcontext lsmctx; - - if (security_secid_to_secctx(&n->lsmblob, &lsmctx, - LSMBLOB_FIRST)) { - audit_log_format(ab, " osid=?"); - if (call_panic) - *call_panic = 2; - } else { - audit_log_format(ab, " obj=%s", lsmctx.context); - security_release_secctx(&lsmctx); - } - } + if (lsmblob_is_set(&n->lsmblob)) + audit_log_object_context(ab, &n->lsmblob); /* log the audit_names record type */ switch (n->type) { @@ -1780,21 +1750,20 @@ static void audit_log_exit(void) struct audit_aux_data_pids *axs = (void *)aux; for (i = 0; i < axs->pid_count; i++) - if (audit_log_pid_context(context, axs->target_pid[i], - axs->target_auid[i], - axs->target_uid[i], - axs->target_sessionid[i], - &axs->target_lsm[i], - axs->target_comm[i])) - call_panic = 1; - } - - if (context->target_pid && - audit_log_pid_context(context, context->target_pid, - context->target_auid, context->target_uid, - context->target_sessionid, - &context->target_lsm, context->target_comm)) - call_panic = 1; + audit_log_pid_context(context, axs->target_pid[i], + axs->target_auid[i], + axs->target_uid[i], + axs->target_sessionid[i], + &axs->target_lsm[i], + axs->target_comm[i]); + } + + if (context->target_pid) + audit_log_pid_context(context, context->target_pid, + context->target_auid, context->target_uid, + context->target_sessionid, + &context->target_lsm, + context->target_comm); if (context->pwd.dentry && context->pwd.mnt) { ab = audit_log_start(context, GFP_KERNEL, AUDIT_CWD); -- 2.37.3

The scaffolding function lsmcontext_init() is no longer used. Remove it. Signed-off-by: Casey Schaufler <casey(a)schaufler-ca.com&gt; --- include/linux/security.h | 19 ------------------- 1 file changed, 19 deletions(-) diff --git a/include/linux/security.h b/include/linux/security.h index c190b9189287..f6a247033556 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -166,25 +166,6 @@ struct lsmcontext { int slot; /* Identifies the module */ }; -/** - * lsmcontext_init - initialize an lsmcontext structure. - * @cp: Pointer to the context to initialize - * @context: Initial context, or NULL - * @size: Size of context, or 0 - * @slot: Which LSM provided the context - * - * Fill in the lsmcontext from the provided information. - * This is a scaffolding function that will be removed when - * lsmcontext integration is complete. - */ -static inline void lsmcontext_init(struct lsmcontext *cp, char *context, - u32 size, int slot) -{ - cp->slot = slot; - cp->context = context; - cp->len = size; -} - /* * Data exported by the security modules * -- 2.37.3

Create a system call to report the list of Linux Security Modules that are active on the system. The list is provided as an array of LSM ID numbers. Signed-off-by: Casey Schaufler <casey(a)schaufler-ca.com&gt; --- arch/x86/entry/syscalls/syscall_64.tbl | 1 + include/linux/syscalls.h | 1 + include/uapi/asm-generic/unistd.h | 5 ++- kernel/sys_ni.c | 1 + security/lsm_syscalls.c | 50 ++++++++++++++++++++++++++ 5 files changed, 57 insertions(+), 1 deletion(-) diff --git a/arch/x86/entry/syscalls/syscall_64.tbl b/arch/x86/entry/syscalls/syscall_64.tbl index 56d5c5202fd0..40b35e7069a7 100644 --- a/arch/x86/entry/syscalls/syscall_64.tbl +++ b/arch/x86/entry/syscalls/syscall_64.tbl @@ -373,6 +373,7 @@ 449 common futex_waitv sys_futex_waitv 450 common set_mempolicy_home_node sys_set_mempolicy_home_node 451 common lsm_self_attr sys_lsm_self_attr +452 common lsm_module_list sys_lsm_module_list # # Due to a historical design error, certain syscalls are numbered differently diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h index 7f87ef8be546..e2e2a9e93e8c 100644 --- a/include/linux/syscalls.h +++ b/include/linux/syscalls.h @@ -1057,6 +1057,7 @@ asmlinkage long sys_set_mempolicy_home_node(unsigned long start, unsigned long l unsigned long home_node, unsigned long flags); asmlinkage long sys_lsm_self_attr(struct lsm_ctx *ctx, size_t *size, int flags); +asmlinkage long sys_lsm_module_list(unsigned int *ids, size_t *size, int flags); /* * Architecture-specific system calls diff --git a/include/uapi/asm-generic/unistd.h b/include/uapi/asm-generic/unistd.h index aa66718e1b48..090617a9a53a 100644 --- a/include/uapi/asm-generic/unistd.h +++ b/include/uapi/asm-generic/unistd.h @@ -889,8 +889,11 @@ __SYSCALL(__NR_set_mempolicy_home_node, sys_set_mempolicy_home_node) #define __NR_lsm_self_attr 451 __SYSCALL(__NR_lsm_self_attr, sys_lsm_self_attr) +#define __NR_lsm_module_list 452 +__SYSCALL(__NR_lsm_module_list, sys_lsm_module_list) + #undef __NR_syscalls -#define __NR_syscalls 452 +#define __NR_syscalls 453 /* * 32 bit systems traditionally used different diff --git a/kernel/sys_ni.c b/kernel/sys_ni.c index 0fdb0341251d..bde9e74a3473 100644 --- a/kernel/sys_ni.c +++ b/kernel/sys_ni.c @@ -264,6 +264,7 @@ COND_SYSCALL(mremap); /* security/lsm_syscalls.c */ COND_SYSCALL(lsm_self_attr); +COND_SYSCALL(lsm_module_list); /* security/keys/keyctl.c */ COND_SYSCALL(add_key); diff --git a/security/lsm_syscalls.c b/security/lsm_syscalls.c index da0fab7065e2..41d9ef945ede 100644 --- a/security/lsm_syscalls.c +++ b/security/lsm_syscalls.c @@ -154,3 +154,53 @@ SYSCALL_DEFINE3(lsm_self_attr, kfree(final); return rc; } + +/** + * lsm_module_list - Return a list of the active security modules + * @ids: the LSM module ids + * @size: size of @ids, updated on return + * @flags: reserved for future use, must be zero + * + * Returns a list of the active LSM ids. On success this function + * returns the number of @ids array elements. This value may be zero + * if there are no LSMs active. If @size is insufficient to contain + * the return data -E2BIG is returned and @size is set to the minimum + * required size. In all other cases a negative value indicating the + * error is returned. + */ +SYSCALL_DEFINE3(lsm_module_list, + unsigned int __user *, ids, + size_t __user *, size, + int, flags) +{ + unsigned int *interum; + size_t total_size = lsm_id * sizeof(*interum); + size_t usize; + int rc; + int i; + + if (get_user(usize, size)) + return -EFAULT; + + if (usize < total_size) { + if (put_user(total_size, size) != 0) + return -EFAULT; + return -E2BIG; + } + + interum = kzalloc(total_size, GFP_KERNEL); + if (interum == NULL) + return -ENOMEM; + + for (i = 0; i < lsm_id; i++) + interum[i] = lsm_idlist[i]->id; + + if (copy_to_user(ids, interum, total_size) != 0 || + put_user(total_size, size) != 0) + rc = -EFAULT; + else + rc = lsm_id; + + kfree(interum); + return rc; +} -- 2.37.3

On 27/09/2022 22:31, Casey Schaufler wrote: With lsm_self_attr(), this would look like a dir/file structure. Would it be useful for user space to list all the currently used LSMs instead of only retrieving information about a known (list of) LSM? What is the use case for this syscall? As for the other syscall, this should also be in the same dedicated "wire syscalls" patch. Same here.