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 <stable@xxxxxxxxxxxxxxx> know about it.
>From 8a5e5e02fc83aaf67053ab53b359af08c6c49aaf Mon Sep 17 00:00:00 2001
From: Vasily Kulikov <segoon@xxxxxxxxxxxx>
Date: Wed, 9 Sep 2015 15:36:00 -0700
Subject: include/linux/poison.h: fix LIST_POISON{1,2} offset
From: Vasily Kulikov <segoon@xxxxxxxxxxxx>
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
Signed-off-by: Vasily Kulikov <segoon@xxxxxxxxxxxx>
Cc: Solar Designer <solar@xxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: "Kirill A. Shutemov" <kirill.shutemov@xxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
include/linux/poison.h | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
--- a/include/linux/poison.h
+++ b/include/linux/poison.h
@@ -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 segoon@xxxxxxxxxxxx are
queue-3.14/include-linux-poison.h-fix-list_poison-1-2-offset.patch
--
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