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authorXi Wang <xi.wang@gmail.com>2012-04-23 04:06:41 -0400
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2012-05-07 08:56:33 -0700
commitfb247af4ccc4b082dbba85d90a42d31fd48affb2 (patch)
treee8332af19731a7a41c93fc84008c1187802aa463
parent8c9def922a843512c403d348dd033aa301e3eefe (diff)
drm/i915: fix integer overflow in i915_gem_execbuffer2()
commit ed8cd3b2cd61004cab85380c52b1817aca1ca49b upstream. 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> Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/gpu/drm/i915/i915_gem_execbuffer.c3
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 4934cf84c320..712153427246 100644
--- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c
+++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
@@ -1296,7 +1296,8 @@ 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_ERROR("execbuf2 with %d buffers\n", args->buffer_count);
return -EINVAL;
}