selinux: restore optimization to selinux_file_permission
Restore the optimization to skip revalidation in selinux_file_permission
if nothing has changed since the dentry_open checks, accidentally removed by
389fb800. Also remove redundant test from selinux_revalidate_file_permission.
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
Reviewed-by: Paul Moore <paul.moore@hp.com>
Acked-by: Eric Paris <eparis@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 15c2a08..d6f6478 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -2938,11 +2938,6 @@
const struct cred *cred = current_cred();
struct inode *inode = file->f_path.dentry->d_inode;
- if (!mask) {
- /* No permission to check. Existence test. */
- return 0;
- }
-
/* file_mask_to_av won't add FILE__WRITE if MAY_APPEND is set */
if ((file->f_flags & O_APPEND) && (mask & MAY_WRITE))
mask |= MAY_APPEND;
@@ -2953,10 +2948,20 @@
static int selinux_file_permission(struct file *file, int mask)
{
+ struct inode *inode = file->f_path.dentry->d_inode;
+ struct file_security_struct *fsec = file->f_security;
+ struct inode_security_struct *isec = inode->i_security;
+ u32 sid = current_sid();
+
if (!mask)
/* No permission to check. Existence test. */
return 0;
+ if (sid == fsec->sid && fsec->isid == isec->sid &&
+ fsec->pseqno == avc_policy_seqno())
+ /* No change since dentry_open check. */
+ return 0;
+
return selinux_revalidate_file_permission(file, mask);
}