Re: [PATCH v26 02/25] LSM: Add the lsmblob data structure.

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. A new lsm_id structure, which contains the name of the LSM and its slot number, is created. There is an instance for each LSM, which assigns the name and passes it to the infrastructure to set the slot. The audit rules data is expanded to use an array of security module data rather than a single instance. Because IMA uses the audit rule functions it is affected as well. Acked-by: Stephen Smalley <sds(a)tycho.nsa.gov&gt; Acked-by: Paul Moore <paul(a)paul-moore.com&gt; Acked-by: John Johansen <john.johansen(a)canonical.com&gt; Signed-off-by: Casey Schaufler <casey(a)schaufler-ca.com&gt; Cc: <bpf(a)vger.kernel.org&gt; Cc: linux-audit(a)redhat.com Cc: linux-security-module(a)vger.kernel.org Cc: selinux(a)vger.kernel.org To: Mimi Zohar <zohar(a)linux.ibm.com&gt; To: Mickaël Salaün <mic(a)linux.microsoft.com&gt; --- include/linux/audit.h | 4 +- include/linux/lsm_hooks.h | 12 ++++- include/linux/security.h | 67 +++++++++++++++++++++++++-- kernel/auditfilter.c | 24 +++++----- kernel/auditsc.c | 13 +++--- security/apparmor/lsm.c | 7 ++- security/bpf/hooks.c | 12 ++++- security/commoncap.c | 7 ++- security/integrity/ima/ima_policy.c | 40 +++++++++++----- security/landlock/cred.c | 2 +- security/landlock/fs.c | 2 +- security/landlock/ptrace.c | 2 +- security/landlock/setup.c | 4 ++ security/landlock/setup.h | 1 + security/loadpin/loadpin.c | 8 +++- security/lockdown/lockdown.c | 7 ++- security/safesetid/lsm.c | 8 +++- security/security.c | 72 ++++++++++++++++++++++++----- security/selinux/hooks.c | 8 +++- security/smack/smack_lsm.c | 7 ++- security/tomoyo/tomoyo.c | 8 +++- security/yama/yama_lsm.c | 7 ++- 22 files changed, 262 insertions(+), 60 deletions(-)

diff --git a/security/landlock/setup.c b/security/landlock/setup.c index f8e8e980454c..4a12666a4090 100644 --- a/security/landlock/setup.c +++ b/security/landlock/setup.c @@ -23,6 +23,10 @@ struct lsm_blob_sizes landlock_blob_sizes __lsm_ro_after_init = { .lbs_superblock = sizeof(struct landlock_superblock_security), }; +struct lsm_id landlock_lsmid __lsm_ro_after_init = { + .lsm = LANDLOCK_NAME,

+}; + static int __init landlock_init(void) { landlock_add_cred_hooks();

diff --git a/security/security.c b/security/security.c index e12a7c463468..a3276deb1b8a 100644 --- a/security/security.c +++ b/security/security.c @@ -344,6 +344,7 @@ 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 @@ -471,21 +472,36 @@ 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 * @count: the number of hooks to add - * @lsm: the name of the security module + * @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, - char *lsm) + struct lsm_id *lsmid) { int i;

+ 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].lsm = lsm; + hooks[i].lsmid = lsmid; hlist_add_tail_rcu(&hooks[i].list, hooks[i].head); }