Patch "include/linux/poison.h: fix LIST_POISON{1,2} offset" has been added to the 3.14-stable tree

This is a note to let you know that I've just added the patch titled

include/linux/poison.h: fix LIST_POISON{1,2} offset

to the 3.14-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
include-linux-poison.h-fix-list_poison-1-2-offset.patch
and it can be found in the queue-3.14 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Vasily Kulikov <[email protected]>
Date: Wed, 9 Sep 2015 15:36:00 -0700
Subject: include/linux/poison.h: fix LIST_POISON{1,2} offset

From: Vasily Kulikov <[email protected]>

commit 8a5e5e02fc83aaf67053ab53b359af08c6c49aaf upstream.

Poison pointer values should be small enough to find a room in non-mmap'able/hardly-mmap'able space. E.g. on x86 "poison pointer space" is located starting from 0x0. Given unprivileged users cannot mmap anything below mmap_min_addr, it should be safe to use poison pointers lower than mmap_min_addr.

The current poison pointer values of LIST_POISON{1,2} might be too big for mmap_min_addr values equal or less than 1 MB (common case, e.g. Ubuntu uses only 0x10000). There is little point to use such a big value given the "poison pointer space" below 1 MB is not yet exhausted. Changing it to a smaller value solves the problem for small mmap_min_addr setups.

The values are suggested by Solar Designer:
http://www.openwall.com/lists/oss-security/2015/05/02/6

---
 include/linux/poison.h |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

@@ -19,8 +19,8 @@
  * under normal circumstances, used to verify that nobody uses
  * non-initialized list entries.
  */
-#define LIST_POISON1  ((void *) 0x00100100 + POISON_POINTER_DELTA)
-#define LIST_POISON2  ((void *) 0x00200200 + POISON_POINTER_DELTA)
+#define LIST_POISON1  ((void *) 0x100 + POISON_POINTER_DELTA)
+#define LIST_POISON2  ((void *) 0x200 + POISON_POINTER_DELTA)
 
 /********** include/linux/timer.h **********/
 /*

Patches currently in stable-queue which might be from [email protected] are

queue-3.14/include-linux-poison.h-fix-list_poison-1-2-offset.patch