Quoting Noralf Trønnes (2017-12-31 13:58:40) > Clear the pointer so the buffer can be re-exported. Otherwise use > after free happens in the next call to drm_gem_prime_handle_to_fd(). > > Signed-off-by: Noralf Trønnes <noralf@xxxxxxxxxxx> > --- > drivers/gpu/drm/drm_prime.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/drivers/gpu/drm/drm_prime.c b/drivers/gpu/drm/drm_prime.c > index 9a17725b0f7a..3214c0eb7466 100644 > --- a/drivers/gpu/drm/drm_prime.c > +++ b/drivers/gpu/drm/drm_prime.c > @@ -343,6 +343,7 @@ void drm_gem_dmabuf_release(struct dma_buf *dma_buf) > > /* drop the reference on the export fd holds */ > drm_gem_object_put_unlocked(obj); > + obj->dma_buf = NULL; obj->dma_buf holds a reference to the dma_buf, so to get to the dma_buf release we must have already called dma_buf_put(obj->dma_buf). See drm_gem_object_exported_dma_buf_free(). (Note you would do the obj->dma_buf = NULL before dropping the potentially last ref to obj.) A BUG_ON(obj->dma_buf) may help clarify the cache was already released. -Chris _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
