2017-10-29 01:48:53 -04:00
|
|
|
From 8a5e5e02fc83aaf67053ab53b359af08c6c49aaf Mon Sep 17 00:00:00 2001
|
|
|
|
|
From: Vasily Kulikov <segoon@openwall.com>
|
|
|
|
|
Date: Wed, 9 Sep 2015 15:36:00 -0700
|
2017-11-07 17:32:46 -05:00
|
|
|
Subject: [PATCH] include/linux/poison.h: fix LIST_POISON{1,2} offset
|
2017-10-29 01:48:53 -04:00
|
|
|
|
|
|
|
|
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@openwall.com>
|
|
|
|
|
Cc: Solar Designer <solar@openwall.com>
|
|
|
|
|
Cc: Thomas Gleixner <tglx@linutronix.de>
|
|
|
|
|
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
|
|
|
|
|
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
|
|
|
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
|
|
|
---
|
|
|
|
|
include/linux/poison.h | 4 ++--
|
|
|
|
|
1 file changed, 2 insertions(+), 2 deletions(-)
|
|
|
|
|
|
|
|
|
|
diff --git a/include/linux/poison.h b/include/linux/poison.h
|
2017-11-07 17:32:46 -05:00
|
|
|
index 2110a81c5e2af..253c9b4198eff 100644
|
2017-10-29 01:48:53 -04:00
|
|
|
--- 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 **********/
|
|
|
|
|
/*
|
