From: Xi Wang Date: Mon, 23 Apr 2012 08:06:41 +0000 (-0400) Subject: drm/i915: fix integer overflow in i915_gem_execbuffer2() X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=ed8cd3b2cd61004cab85380c52b1817aca1ca49b;p=GitHub%2Fmt8127%2Fandroid_kernel_alcatel_ttab.git drm/i915: fix integer overflow in i915_gem_execbuffer2() 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 Reviewed-by: Chris Wilson Cc: stable@vger.kernel.org Signed-off-by: Daniel Vetter --- diff --git a/drivers/gpu/drm/i915/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/i915_gem_execbuffer.c index f51a696486cb..7c50e58175c0 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; }