| Message ID | 20201006135228.113259-2-gprocida@google.com |
|---|---|
| State | New |
| Headers | show |
| Series | [1/1] drm/syncobj: Fix drm_syncobj_handle_to_fd refcount leak | expand |
On Tue, Oct 06, 2020 at 02:52:28PM +0100, Giuliano Procida wrote: > commit e7cdf5c82f1773c3386b93bbcf13b9bfff29fa31 upstream. That's not what this commit is :( Are you sure this is correct? > The cherry-pick 5fb252cad61f of the above commit introduced a refcount > imbalance and so leak of struct drm_syncobj objects that can be > triggered with DRM_IOCTL_SYNCOBJ_HANDLE_TO_FD. Ok, so the backport of e7cdf5c82f1773c3386b93bbcf13b9bfff29fa31 is the problem, so this needs a bit of wording change to make it obvious what is happening here. Can you fix that up and resend? thanks, greg k-h
diff --git a/drivers/gpu/drm/drm_syncobj.c b/drivers/gpu/drm/drm_syncobj.c index 889c95d4feec..3f71bc3d93fe 100644 --- 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(struct drm_file *file_private, return PTR_ERR(file); } - drm_syncobj_get(syncobj); fd_install(fd, file); *p_fd = fd;
commit e7cdf5c82f1773c3386b93bbcf13b9bfff29fa31 upstream. The cherry-pick 5fb252cad61f of the above commit introduced a refcount imbalance and so leak of struct drm_syncobj objects that 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> --- drivers/gpu/drm/drm_syncobj.c | 1 - 1 file changed, 1 deletion(-)