tree fcfe808968508a7c1aa6e93ded9bc6d3944b6c68
parent 60942f2f235ce7b817166cdf355eed729094834d
author Christoph Hellwig <hch@lst.de> 1399201412 +0200
committer Al Viro <viro@zeniv.linux.org.uk> 1399399122 -0400

posix_acl: handle NULL ACL in posix_acl_equiv_mode

Various filesystems don't bother checking for a NULL ACL in
posix_acl_equiv_mode, and thus can dereference a NULL pointer when it
gets passed one. This usually happens from the NFS server, as the ACL tools
never pass a NULL ACL, but instead of one representing the mode bits.

Instead of adding boilerplat to all filesystems put this check into one place,
which will allow us to remove the check from other filesystems as well later
on.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reported-by: Ben Greear <greearb@candelatech.com>
Reported-by: Marco Munderloh <munderl@tnt.uni-hannover.de>,
Cc: Chuck Lever <chuck.lever@oracle.com>
Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>