releases/4.9.28/9p-fix-a-potential-acl-leak.patch

   1 From b5c66bab72a6a65edb15beb60b90d3cb84c5763b Mon Sep 17 00:00:00 2001
   2 From: Cong Wang <xiyou.wangcong@gmail.com>
   3 Date: Wed, 22 Feb 2017 15:40:53 -0800
   4 Subject: 9p: fix a potential acl leak
   5
   6 From: Cong Wang <xiyou.wangcong@gmail.com>
   7
   8 commit b5c66bab72a6a65edb15beb60b90d3cb84c5763b upstream.
   9
  10 posix_acl_update_mode() could possibly clear 'acl', if so we leak the
  11 memory pointed by 'acl'.  Save this pointer before calling
  12 posix_acl_update_mode() and release the memory if 'acl' really gets
  13 cleared.
  14
  15 Link: http://lkml.kernel.org/r/1486678332-2430-1-git-send-email-xiyou.wangcong@gmail.com
  16 Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
  17 Reported-by: Mark Salyzyn <salyzyn@android.com>
  18 Reviewed-by: Jan Kara <jack@suse.cz>
  19 Reviewed-by: Greg Kurz <groug@kaod.org>
  20 Cc: Eric Van Hensbergen <ericvh@gmail.com>
  21 Cc: Ron Minnich <rminnich@sandia.gov>
  22 Cc: Latchesar Ionkov <lucho@ionkov.net>
  23 Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
  24 Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
  25 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  26
  27 ---
  28  fs/9p/acl.c |    2 ++
  29  1 file changed, 2 insertions(+)
  30
  31 --- a/fs/9p/acl.c
  32 +++ b/fs/9p/acl.c
  33 @@ -277,6 +277,7 @@ static int v9fs_xattr_set_acl(const stru
  34         case ACL_TYPE_ACCESS:
  35                 if (acl) {
  36                         struct iattr iattr;
  37 +                       struct posix_acl *old_acl = acl;
  38
  39                         retval = posix_acl_update_mode(inode, &iattr.ia_mode, &acl);
  40                         if (retval)
  41 @@ -287,6 +288,7 @@ static int v9fs_xattr_set_acl(const stru
  42                                  * by the mode bits. So don't
  43                                  * update ACL.
  44                                  */
  45 +                               posix_acl_release(old_acl);
  46                                 value = NULL;
  47                                 size = 0;
  48                         }