diff --git a/drivers/gpu/drm/i915/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
index 5b8213b1a8c7e587cf19390e8efef0528a6bd738..435ed95df144c1bc54d438c892a4a63c8a1b3cba 100644
--- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c
+++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
@@ -2104,6 +2104,11 @@ get_fence_array(struct drm_i915_gem_execbuffer2 *args,
 			goto err;
 		}
 
+		if (fence.flags & __I915_EXEC_FENCE_UNKNOWN_FLAGS) {
+			err = -EINVAL;
+			goto err;
+		}
+
 		syncobj = drm_syncobj_find(file, fence.handle);
 		if (!syncobj) {
 			DRM_DEBUG("Invalid syncobj handle provided\n");
@@ -2111,6 +2116,9 @@ get_fence_array(struct drm_i915_gem_execbuffer2 *args,
 			goto err;
 		}
 
+		BUILD_BUG_ON(~(ARCH_KMALLOC_MINALIGN - 1) &
+			     ~__I915_EXEC_FENCE_UNKNOWN_FLAGS);
+
 		fences[n] = ptr_pack_bits(syncobj, fence.flags, 2);
 	}
 
diff --git a/include/uapi/drm/i915_drm.h b/include/uapi/drm/i915_drm.h
index 125bde7d95045e80473a0e709ac7943a8cb9d5cd..ac3c6503ca27f156ddbc3dd304bbf91671a9ac2a 100644
--- a/include/uapi/drm/i915_drm.h
+++ b/include/uapi/drm/i915_drm.h
@@ -839,6 +839,7 @@ struct drm_i915_gem_exec_fence {
 
 #define I915_EXEC_FENCE_WAIT            (1<<0)
 #define I915_EXEC_FENCE_SIGNAL          (1<<1)
+#define __I915_EXEC_FENCE_UNKNOWN_FLAGS (-(I915_EXEC_FENCE_SIGNAL << 1))
 	__u32 flags;
 };