From: Giuliano Procida gprocida@google.com
Commit 5fb252cad61f20ae5d5a8b199f6cc4faf6f418e1, a cherry-pick of upstream commit e7cdf5c82f1773c3386b93bbcf13b9bfff29fa31, introduced a refcount imbalance and thus a struct drm_syncobj object leak which can be triggered with DRM_IOCTL_SYNCOBJ_HANDLE_TO_FD.
The function drm_syncobj_handle_to_fd first calls drm_syncobj_find which increments the refcount of the object on success. In all of the drm_syncobj_handle_to_fd error paths, the refcount is decremented, but in the success path the refcount should remain at +1 as the struct drm_syncobj now belongs to the newly opened file. Instead, the refcount was incremented again to +2.
Fixes: 5fb252cad61f ("drm/syncobj: Stop reusing the same struct file for all syncobj -> fd") Signed-off-by: Giuliano Procida gprocida@google.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/gpu/drm/drm_syncobj.c | 1 - 1 file changed, 1 deletion(-)
--- a/drivers/gpu/drm/drm_syncobj.c +++ b/drivers/gpu/drm/drm_syncobj.c @@ -355,7 +355,6 @@ static int drm_syncobj_handle_to_fd(stru return PTR_ERR(file); }
- drm_syncobj_get(syncobj); fd_install(fd, file);
*p_fd = fd;