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* [PATCH v2 1/2] drm/i915: fix integer overflow in i915_gem_execbuffer2()
@ 2012-04-23  8:06 ` Xi Wang
  0 siblings, 0 replies; 9+ messages in thread
From: Xi Wang @ 2012-04-23  8:06 UTC (permalink / raw)
  To: Daniel Vetter, Keith Packard
  Cc: security, intel-gfx, linux-kernel, dri-devel, stable

On 32-bit systems, a large args->buffer_count from userspace via ioctl
may overflow the allocation size, leading to out-of-bounds access.

This vulnerability was introduced in commit 8408c282 ("drm/i915:
First try a normal large kmalloc for the temporary exec buffers").

Signed-off-by: Xi Wang <xi.wang@gmail.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: stable@vger.kernel.org
---
 drivers/gpu/drm/i915/i915_gem_execbuffer.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
index f51a696..7c50e58 100644
--- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c
+++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
@@ -1404,7 +1404,8 @@ i915_gem_execbuffer2(struct drm_device *dev, void *data,
 	struct drm_i915_gem_exec_object2 *exec2_list = NULL;
 	int ret;
 
-	if (args->buffer_count < 1) {
+	if (args->buffer_count < 1 ||
+	    args->buffer_count > UINT_MAX / sizeof(*exec2_list)) {
 		DRM_DEBUG("execbuf2 with %d buffers\n", args->buffer_count);
 		return -EINVAL;
 	}
-- 
1.7.5.4

^ permalink raw reply related	[flat|nested] 9+ messages in thread

end of thread, other threads:[~2012-04-23 20:43 UTC | newest]

Thread overview: 9+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2012-04-23  8:06 [PATCH v2 1/2] drm/i915: fix integer overflow in i915_gem_execbuffer2() Xi Wang
2012-04-23  8:06 ` Xi Wang
2012-04-23  8:06 ` [PATCH v2 2/2] drm/i915: fix integer overflow in i915_gem_do_execbuffer() Xi Wang
2012-04-23  8:18   ` Chris Wilson
2012-04-23  8:18     ` Chris Wilson
2012-04-23  8:18 ` [PATCH v2 1/2] drm/i915: fix integer overflow in i915_gem_execbuffer2() Chris Wilson
2012-04-23  8:18   ` Chris Wilson
2012-04-23 20:44   ` Daniel Vetter
2012-04-23 20:44     ` Daniel Vetter

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