On Wed, 2021-12-15 at 15:02 -0500, Zack Rusin wrote:

From: Zack Rusin zackr@vmware.com

vmw_user_bo_lookup can fail to lookup user buffers, especially because the buffer handles come from the userspace. The return value has to be checked before the buffers are put back.

This was spotted by Dan's Smatch statick checker: drivers/gpu/drm/vmwgfx/vmwgfx_bo.c:574 vmw_user_bo_synccpu_release() error: uninitialized symbol 'vmw_bo'.

Signed-off-by: Zack Rusin zackr@vmware.com Reported-by: Dan Carpenter dan.carpenter@oracle.com Fixes: 8afa13a0583f ("drm/vmwgfx: Implement DRIVER_GEM")

---

drivers/gpu/drm/vmwgfx/vmwgfx_bo.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_bo.c b/drivers/gpu/drm/vmwgfx/vmwgfx_bo.c index 15fead85450c..31aecc46624b 100644 --- a/drivers/gpu/drm/vmwgfx/vmwgfx_bo.c +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_bo.c @@ -568,10 +568,12 @@ static int vmw_user_bo_synccpu_release(struct drm_file *filp, struct vmw_buffer_object *vmw_bo; int ret = vmw_user_bo_lookup(filp, handle, &vmw_bo);

• if (!(flags & drm_vmw_synccpu_allow_cs)) {

• atomic_dec(&vmw_bo->cpu_writers);
  

• if (!ret) {

• if (!(flags & drm_vmw_synccpu_allow_cs)) {
  

• 	atomic_dec(&vmw_bo->cpu_writers);
  

• }
  

• ttm_bo_put(&vmw_bo->base);
  

  }

• ttm_bo_put(&vmw_bo->base);

  return ret;

}

Reviewed-by: Martin Krastev krastevm@vmware.com