SELinux: don't check permissions for kernel mounts

Don't bother checking permissions when the kernel performs an
internal mount, as this should always be allowed.

Signed-off-by: James Morris <jmorris@namei.org>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>

1 files changed, 4 insertions, 0 deletions

diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 7465d713b53..853b58c8b2c 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -2484,6 +2484,10 @@ static int selinux_sb_kern_mount(struct super_block *sb, int flags, void *data)
         if (rc)
                 return rc;
 
+        /* Allow all mounts performed by the kernel */
+        if (flags & MS_KERNMOUNT)
+                return 0;
+
         AVC_AUDIT_DATA_INIT(&ad, FS);
         ad.u.fs.path.dentry = sb->s_root;
         return superblock_has_perm(cred, sb, FILESYSTEM__MOUNT, &ad);