[PATCH v22 07/23] LSM: Use lsmblob in security_ipc_getsecid

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 <sds(a)tycho.nsa.gov&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 fad361bf320e..be8db737da74 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -499,7 +499,7 @@ 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); @@ -1228,9 +1228,10 @@ 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 5f9bdd62f78d..35d6bd0526a2 100644 --- a/kernel/auditsc.c +++ b/kernel/auditsc.c @@ -2341,11 +2341,16 @@ 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 ea927a00de18..9c1098ecea03 100644 --- a/security/security.c +++ b/security/security.c @@ -1882,10 +1882,16 @@ 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) -- 2.24.1