1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
|
Delivered-To: jwboyer@gmail.com
Received: by 10.76.169.233 with SMTP id ah9csp107244oac;
Mon, 11 Mar 2013 17:32:43 -0700 (PDT)
X-Received: by 10.68.195.70 with SMTP id ic6mr32376980pbc.60.1363048363048;
Mon, 11 Mar 2013 17:32:43 -0700 (PDT)
Return-Path: <linux-kernel-owner@vger.kernel.org>
Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67])
by mx.google.com with ESMTP id xm3si25923071pbc.196.2013.03.11.17.32.12;
Mon, 11 Mar 2013 17:32:43 -0700 (PDT)
Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Authentication-Results: mx.google.com;
spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mail=linux-kernel-owner@vger.kernel.org
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
id S1754633Ab3CLAbx (ORCPT <rfc822;cpulmkl@gmail.com> + 99 others);
Mon, 11 Mar 2013 20:31:53 -0400
Received: from smtp.outflux.net ([198.145.64.163]:48630 "EHLO smtp.outflux.net"
rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP
id S1754446Ab3CLAbx (ORCPT <rfc822;linux-kernel@vger.kernel.org>);
Mon, 11 Mar 2013 20:31:53 -0400
Received: from www.outflux.net (serenity-end.outflux.net [10.2.0.2])
by vinyl.outflux.net (8.14.4/8.14.4/Debian-2ubuntu2) with ESMTP id r2C0VjYO004342;
Mon, 11 Mar 2013 17:31:45 -0700
Date: Mon, 11 Mar 2013 17:31:45 -0700
From: Kees Cook <keescook@chromium.org>
To: linux-kernel@vger.kernel.org
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>,
David Airlie <airlied@linux.ie>,
dri-devel@lists.freedesktop.org, intel-gfx@lists.freedesktop.org,
Julien Tinnes <jln@google.com>, marcheu@chromium.org
Subject: [PATCH v3] drm/i915: bounds check execbuffer relocation count
Message-ID: <20130312003145.GA28993@www.outflux.net>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
X-MIMEDefang-Filter: outflux$Revision: 1.316 $
X-HELO: www.outflux.net
X-Scanned-By: MIMEDefang 2.71 on 10.2.0.1
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org
It is possible to wrap the counter used to allocate the buffer for
relocation copies. This could lead to heap writing overflows.
CVE-2013-0913
v3: collapse test, improve comment
v2: move check into validate_exec_list
Signed-off-by: Kees Cook <keescook@chromium.org>
Reported-by: Pinkie Pie
Cc: stable@vger.kernel.org
---
drivers/gpu/drm/i915/i915_gem_execbuffer.c | 11 ++++++++---
1 file changed, 8 insertions(+), 3 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
index b3a40ee..094ba41 100644
--- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c
+++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
@@ -732,6 +732,8 @@ validate_exec_list(struct drm_i915_gem_exec_object2 *exec,
int count)
{
int i;
+ int relocs_total = 0;
+ int relocs_max = INT_MAX / sizeof(struct drm_i915_gem_relocation_entry);
for (i = 0; i < count; i++) {
char __user *ptr = (char __user *)(uintptr_t)exec[i].relocs_ptr;
@@ -740,10 +742,13 @@ validate_exec_list(struct drm_i915_gem_exec_object2 *exec,
if (exec[i].flags & __EXEC_OBJECT_UNKNOWN_FLAGS)
return -EINVAL;
- /* First check for malicious input causing overflow */
- if (exec[i].relocation_count >
- INT_MAX / sizeof(struct drm_i915_gem_relocation_entry))
+ /* First check for malicious input causing overflow in
+ * the worst case where we need to allocate the entire
+ * relocation tree as a single array.
+ */
+ if (exec[i].relocation_count > relocs_max - relocs_total)
return -EINVAL;
+ relocs_total += exec[i].relocation_count;
length = exec[i].relocation_count *
sizeof(struct drm_i915_gem_relocation_entry);
--
1.7.9.5
--
Kees Cook
Chrome OS Security
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
|
