apparmor: fix change_hat not finding hat after policy replacement

After a policy replacement, the task cred may be out of date and need
to be updated. However change_hat is using the stale profiles from
the out of date cred resulting in either: a stale profile being applied
or, incorrect failure when searching for a hat profile as it has been
migrated to the new parent profile.

Fixes: 01e2b670aa898a39259bc85c78e3d74820f4d3b6 (failure to find hat)
Fixes: 898127c34ec03291c86f4ff3856d79e9e18952bc (stale policy being applied)
Bugzilla: https://bugzilla.suse.com/show_bug.cgi?id=1000287
Cc: stable@vger.kernel.org
Signed-off-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>

1 files changed, 4 insertions, 2 deletions

diff --git a/security/apparmor/domain.c b/security/apparmor/domain.c
index fc3036b34e51..a4d90aa1045a 100644
--- a/security/apparmor/domain.c
+++ b/security/apparmor/domain.c
@@ -621,8 +621,8 @@ int aa_change_hat(const char *hats[], int count, u64 token, bool permtest)
         /* released below */
         cred = get_current_cred();
         cxt = cred_cxt(cred);
-        profile = aa_cred_profile(cred);
-        previous_profile = cxt->previous;
+        profile = aa_get_newest_profile(aa_cred_profile(cred));
+        previous_profile = aa_get_newest_profile(cxt->previous);
 
         if (unconfined(profile)) {
                 info = "unconfined";
@@ -718,6 +718,8 @@ audit:
 out:
         aa_put_profile(hat);
         kfree(name);
+        aa_put_profile(profile);
+        aa_put_profile(previous_profile);
         put_cred(cred);
 
         return error;