Log the anonymous inode class name in the security hook
inode_init_security_anon. This name is the key for name based type
transitions on the anon_inode security class on creation. Example:
type=AVC msg=audit(02/16/22 22:02:50.585:216) : avc: granted { create } for pid=2136 comm=mariadbd anonclass="[io_uring]" dev="anon_inodefs" ino=6871 scontext=system_u:system_r:mysqld_t:s0 tcontext=system_u:system_r:mysqld_iouring_t:s0 tclass=anon_inode
Add a new LSM audit data type holding the inode and the class name.
Also warn if the security hook gets called with no name set; currently
the only caller fs/anon_inodes.c:anon_inode_make_secure_inode() passes
one.
Signed-off-by: Christian Göttsche <cgzones@xxxxxxxxxxxxxx>
---
include/linux/lsm_audit.h | 5 +++++
security/lsm_audit.c | 21 +++++++++++++++++++++
security/selinux/hooks.c | 7 +++++--
3 files changed, 31 insertions(+), 2 deletions(-)
diff --git a/include/linux/lsm_audit.h b/include/linux/lsm_audit.h
index 17d02eda9538..8135a88d6d82 100644
--- a/include/linux/lsm_audit.h
+++ b/include/linux/lsm_audit.h
@@ -76,6 +76,7 @@ struct common_audit_data {
#define LSM_AUDIT_DATA_IBENDPORT 14
#define LSM_AUDIT_DATA_LOCKDOWN 15
#define LSM_AUDIT_DATA_NOTIFICATION 16
+#define LSM_AUDIT_DATA_ANONINODE 17
union {
struct path path;
struct dentry *dentry;
@@ -96,6 +97,10 @@ struct common_audit_data {
struct lsm_ibpkey_audit *ibpkey;
struct lsm_ibendport_audit *ibendport;
int reason;
+ struct {
+ struct inode *inode;
+ const char *anonclass;
+ } anoninode_struct;
} u;
/* this union contains LSM specific data */
union {
diff --git a/security/lsm_audit.c b/security/lsm_audit.c
index 1897cbf6fc69..5545fed35539 100644
--- a/security/lsm_audit.c
+++ b/security/lsm_audit.c
@@ -433,6 +433,27 @@ static void dump_common_audit_data(struct audit_buffer *ab,
audit_log_format(ab, " lockdown_reason=\"%s\"",
lockdown_reasons[a->u.reason]);
break;
+ case LSM_AUDIT_DATA_ANONINODE: {
+ struct dentry *dentry;
+ struct inode *inode;
+
+ rcu_read_lock();
+ inode = a->u.anoninode_struct.inode;
+ dentry = d_find_alias_rcu(inode);
+ if (dentry) {
+ audit_log_format(ab, " name=");
+ spin_lock(&dentry->d_lock);
+ audit_log_untrustedstring(ab, dentry->d_name.name);
+ spin_unlock(&dentry->d_lock);
+ }
+ audit_log_format(ab, " anonclass=");
+ audit_log_untrustedstring(ab, a->u.anoninode_struct.anonclass);
+ audit_log_format(ab, " dev=");
+ audit_log_untrustedstring(ab, inode->i_sb->s_id);
+ audit_log_format(ab, " ino=%lu", inode->i_ino);
+ rcu_read_unlock();
+ break;
+ }
} /* switch (a->type) */
}
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index dafabb4dcc64..19c831d94d9b 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -2932,6 +2932,8 @@ static int selinux_inode_init_security_anon(struct inode *inode,
if (unlikely(!selinux_initialized(&selinux_state)))
return 0;
+ WARN_ON(!name);
+
isec = selinux_inode(inode);
/*
@@ -2965,8 +2967,9 @@ static int selinux_inode_init_security_anon(struct inode *inode,
* allowed to actually create this type of anonymous inode.
*/
- ad.type = LSM_AUDIT_DATA_INODE;
- ad.u.inode = inode;
+ ad.type = LSM_AUDIT_DATA_ANONINODE;
+ ad.u.anoninode_struct.inode = inode;
+ ad.u.anoninode_struct.anonclass = name ? (const char *)name->name : "unknown(null)";
return avc_has_perm(&selinux_state,
tsec->sid,
--
2.35.1
