commit 880db7a8dbed226d638b3a48aa1a3996f8624911
Author: Eric Anholt <eric@anholt.net>
Date:   Wed Sep 10 14:22:49 2008 -0700

    drm: Avoid oops in GEM execbuffers with bad arguments.
    
    Signed-off-by: Eric Anholt <eric@anholt.net>

diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 5fe5034..29d9d21 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -1763,6 +1763,10 @@ i915_gem_execbuffer(struct drm_device *dev, void *data,
 		  (int) args->buffers_ptr, args->buffer_count, args->batch_len);
 #endif
 
+	if (args->buffer_count < 1) {
+		DRM_ERROR("execbuf with %d buffers\n", args->buffer_count);
+		return -EINVAL;
+	}
 	/* Copy in the exec list from userland */
 	exec_list = drm_calloc(sizeof(*exec_list), args->buffer_count,
 			       DRM_MEM_DRIVER);