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| author | Vasily Kulikov <segoon@openwall.com> | 2016-01-08 11:19:14 -0500 |
|---|---|---|
| committer | Wolfgang Wiedmeyer <wolfgit@wiedmeyer.de> | 2016-03-18 01:51:05 +0100 |
| commit | 2ec4bf02eca166ffef86d85732bb5bfc0f6b64d9 (patch) | |
| tree | 4f6fd702ae4683829d6bc53491c0ab8348fdfc93 | |
| parent | 8488e8e35c1cad73257500e300873083c951d9d6 (diff) | |
| download | kernel_samsung_smdk4412-2ec4bf02eca166ffef86d85732bb5bfc0f6b64d9.zip kernel_samsung_smdk4412-2ec4bf02eca166ffef86d85732bb5bfc0f6b64d9.tar.gz kernel_samsung_smdk4412-2ec4bf02eca166ffef86d85732bb5bfc0f6b64d9.tar.bz2 | |
include/linux/poison.h: fix LIST_POISON{1,2} offset
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
Bug: 26186802
Change-Id: I2663f4e4d8725547c90ea14e082f10ae0cf80679
Signed-off-by: Yuan Lin <yualin@google.com>
| -rw-r--r-- | include/linux/poison.h | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/include/linux/poison.h b/include/linux/poison.h index 2110a81..253c9b4 100644 --- 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 **********/ /* |