[GIT PULL][SECURITY] Apparmor bugfix

[James Morris]

Please pull this fix for 4.9.

>From JJ: "This is a fix for a policy replacement bug that is fairly 
serious for apache mod_apparmor users, as it results in the wrong policy 
being applied on an network facing service."


The following changes since commit 9c763584b7c8911106bb77af7e648bef09af9d80:

  Linux 4.9-rc6 (2016-11-20 13:52:19 -0800)

are available in the git repository at:
  git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security.git for-linus

John Johansen (1):
      apparmor: fix change_hat not finding hat after policy replacement

 security/apparmor/domain.c |    6 ++++--
 1 files changed, 4 insertions(+), 2 deletions(-)

---

commit 3d40658c977769ce2138f286cf131537bf68bdfe
Author: John Johansen <john.johansen@xxxxxxxxxxxxx>
Date:   Wed Aug 31 21:10:06 2016 -0700

    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    After a policy replacement, the task cred may be out of date and need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    the out of date cred resulting in either: a stale profile being applied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@xxxxxxxxxxxxxxx
    Signed-off-by: John Johansen <john.johansen@xxxxxxxxxxxxx>
    Signed-off-by: James Morris <james.l.morris@xxxxxxxxxx>

diff --git a/security/apparmor/domain.c b/security/apparmor/domain.c
index fc3036b..a4d90aa 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 @@ int aa_change_hat(const char *hats[], int count, u64 token, bool permtest)
 out:
 	aa_put_profile(hat);
 	kfree(name);
+	aa_put_profile(profile);
+	aa_put_profile(previous_profile);
 	put_cred(cred);
 
 	return error;