[PATCH 1/1] virtio-gpu: avoid possible NULL pointer dereference

From	Heinrich Schuchardt <xypron.glpk@gmx.de>
Newsgroups	linux.kernel
Subject	[PATCH 1/1] virtio-gpu: avoid possible NULL pointer dereference
Date	2016-08-21 23:10 +0200
Message-ID	<s8Iad-5xs-7@gated-at.bofh.it> (permalink)
Organization	linux.* mail to news gateway

Show all headers | View raw

If output is NULL it is not permissable to dereference it.
So we should leave the respective function in this case.

The inconsistency was indicated by cppcheck.
No actual NULL pointer dereference was observed.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
---
 drivers/gpu/drm/virtio/virtgpu_plane.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/virtio/virtgpu_plane.c b/drivers/gpu/drm/virtio/virtgpu_plane.c
index 925ca25..ba28c0f 100644
--- a/drivers/gpu/drm/virtio/virtgpu_plane.c
+++ b/drivers/gpu/drm/virtio/virtgpu_plane.c
@@ -76,7 +76,8 @@ static void virtio_gpu_primary_plane_update(struct drm_plane *plane,
 		output = drm_crtc_to_virtio_gpu_output(plane->state->crtc);
 	if (old_state->crtc)
 		output = drm_crtc_to_virtio_gpu_output(old_state->crtc);
-	WARN_ON(!output);
+	if (WARN_ON(!output))
+		return;
 
 	if (plane->state->fb) {
 		vgfb = to_virtio_gpu_framebuffer(plane->state->fb);
@@ -129,7 +130,8 @@ static void virtio_gpu_cursor_plane_update(struct drm_plane *plane,
 		output = drm_crtc_to_virtio_gpu_output(plane->state->crtc);
 	if (old_state->crtc)
 		output = drm_crtc_to_virtio_gpu_output(old_state->crtc);
-	WARN_ON(!output);
+	if (WARN_ON(!output))
+		return;
 
 	if (plane->state->fb) {
 		vgfb = to_virtio_gpu_framebuffer(plane->state->fb);
-- 
2.1.4

Back to linux.kernel | Previous | Next | Find similar | Unroll thread

Thread

[PATCH 1/1] virtio-gpu: avoid possible NULL pointer dereference Heinrich Schuchardt <xypron.glpk@gmx.de> - 2016-08-21 23:10 +0200

csiph-web