This is a note to let you know that I've just added the patch titled
drm/i915: bounds check execbuffer relocation count
to the 3.4-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:
drm-i915-bounds-check-execbuffer-relocation-count.patch
and it can be found in the queue-3.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 3118a4f652c7b12c752f3222af0447008f9b2368 Mon Sep 17 00:00:00 2001
From: Kees Cook <keescook@xxxxxxxxxxxx>
Date: Mon, 11 Mar 2013 17:31:45 -0700
Subject: drm/i915: bounds check execbuffer relocation count
From: Kees Cook <keescook@xxxxxxxxxxxx>
commit 3118a4f652c7b12c752f3222af0447008f9b2368 upstream.
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@xxxxxxxxxxxx>
Reported-by: Pinkie Pie
Reviewed-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Daniel Vetter <daniel.vetter@xxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/gpu/drm/i915/i915_gem_execbuffer.c | 11 ++++++++---
1 file changed, 8 insertions(+), 3 deletions(-)
--- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c
+++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
@@ -957,15 +957,20 @@ validate_exec_list(struct drm_i915_gem_e
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;
int length; /* limited by fault_in_pages_readable() */
- /* 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);
Patches currently in stable-queue which might be from keescook@xxxxxxxxxxxx are
queue-3.4/drm-i915-bounds-check-execbuffer-relocation-count.patch
queue-3.4/drm-i915-restrict-kernel-address-leak-in-debugfs.patch
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