From: Vladimir Sementsov-Ogievskiy <vsement...@virtuozzo.com> Backing may be zero after failed bdrv_attach_child in bdrv_set_backing_hd, which leads to SIGSEGV.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsement...@virtuozzo.com> Message-id: 20170928120300.58164-1-vsement...@virtuozzo.com Reviewed-by: John Snow <js...@redhat.com> Signed-off-by: Max Reitz <mre...@redhat.com> --- block/mirror.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/block/mirror.c b/block/mirror.c index 459b80f8f3..3b6f0c5772 100644 --- a/block/mirror.c +++ b/block/mirror.c @@ -1058,6 +1058,11 @@ static int coroutine_fn bdrv_mirror_top_pdiscard(BlockDriverState *bs, static void bdrv_mirror_top_refresh_filename(BlockDriverState *bs, QDict *opts) { + if (bs->backing == NULL) { + /* we can be here after failed bdrv_attach_child in + * bdrv_set_backing_hd */ + return; + } bdrv_refresh_filename(bs->backing->bs); pstrcpy(bs->exact_filename, sizeof(bs->exact_filename), bs->backing->bs->filename); -- 2.13.6