tree 1de0a003e5f230a2f5dfd63dfa837488ef8a728a
parent aa93d1fee85c890a34f2510a310e55ee76a27848
author Jann Horn <jann@thejh.net> 1442000373 +0200
committer Linus Torvalds <torvalds@linux-foundation.org> 1468618206 +0900

xfs: fix type confusion in xfs_ioc_swapext

Without this check, the following XFS_I invocations would return bad
pointers when used on non-XFS inodes (perhaps pointers into preceding
allocator chunks).

This could be used by an attacker to trick xfs_swap_extents into
performing locking operations on attacker-chosen structures in kernel
memory, potentially leading to code execution in the kernel.  (I have
not investigated how likely this is to be usable for an attack in
practice.)

Signed-off-by: Jann Horn <jann@thejh.net>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Dave Chinner <david@fromorbit.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>