mirror of
https://github.com/Divested-Mobile/DivestOS-Build.git
synced 2024-10-01 01:35:54 -04:00
46 lines
1.6 KiB
Diff
46 lines
1.6 KiB
Diff
|
From ab676b7d6fbf4b294bf198fb27ade5b0e865c7ce Mon Sep 17 00:00:00 2001
|
||
|
|
From: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
|
||
|
|
Date: Mon, 9 Mar 2015 23:11:12 +0200
|
||
|
|
Subject: pagemap: do not leak physical addresses to non-privileged userspace
|
||
|
|
|
||
|
|
As pointed by recent post[1] on exploiting DRAM physical imperfection,
|
||
|
|
/proc/PID/pagemap exposes sensitive information which can be used to do
|
||
|
|
attacks.
|
||
|
|
|
||
|
|
This disallows anybody without CAP_SYS_ADMIN to read the pagemap.
|
||
|
|
|
||
|
|
[1] http://googleprojectzero.blogspot.com/2015/03/exploiting-dram-rowhammer-bug-to-gain.html
|
||
|
|
|
||
|
|
[ Eventually we might want to do anything more finegrained, but for now
|
||
|
|
this is the simple model. - Linus ]
|
||
|
|
|
||
|
|
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
|
||
|
|
Acked-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
|
||
|
|
Acked-by: Andy Lutomirski <luto@amacapital.net>
|
||
|
|
Cc: Pavel Emelyanov <xemul@parallels.com>
|
||
|
|
Cc: Andrew Morton <akpm@linux-foundation.org>
|
||
|
|
Cc: Mark Seaborn <mseaborn@chromium.org>
|
||
|
|
Cc: stable@vger.kernel.org
|
||
|
|
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
||
|
|
---
|
||
|
|
fs/proc/task_mmu.c | 3 +++
|
||
|
|
1 file changed, 3 insertions(+)
|
||
|
|
|
||
|
|
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
|
||
|
|
index 956b75d..6dee68d 100644
|
||
|
|
--- a/fs/proc/task_mmu.c
|
||
|
|
+++ b/fs/proc/task_mmu.c
|
||
|
|
@@ -1325,6 +1325,9 @@ out:
|
||
|
|
|
||
|
|
static int pagemap_open(struct inode *inode, struct file *file)
|
||
|
|
{
|
||
|
|
+ /* do not disclose physical addresses: attack vector */
|
||
|
|
+ if (!capable(CAP_SYS_ADMIN))
|
||
|
|
+ return -EPERM;
|
||
|
|
pr_warn_once("Bits 55-60 of /proc/PID/pagemap entries are about "
|
||
|
|
"to stop being page-shift some time soon. See the "
|
||
|
|
"linux/Documentation/vm/pagemap.txt for details.\n");
|
||
|
|
--
|
||
|
|
cgit v1.1
|
||
|
|
|