From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:56750) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1e0Uyd-0001Qu-TY for qemu-devel@nongnu.org; Fri, 06 Oct 2017 11:55:52 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1e0Uyd-0004PO-40 for qemu-devel@nongnu.org; Fri, 06 Oct 2017 11:55:51 -0400 From: Kevin Wolf Date: Fri, 6 Oct 2017 17:54:18 +0200 Message-Id: <20171006155422.10135-51-kwolf@redhat.com> In-Reply-To: <20171006155422.10135-1-kwolf@redhat.com> References: <20171006155422.10135-1-kwolf@redhat.com> Subject: [Qemu-devel] [PULL 50/54] block/mirror: check backing in bdrv_mirror_top_refresh_filename List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-block@nongnu.org Cc: kwolf@redhat.com, qemu-devel@nongnu.org From: Vladimir Sementsov-Ogievskiy Backing may be zero after failed bdrv_attach_child in bdrv_set_backing_hd, which leads to SIGSEGV. Signed-off-by: Vladimir Sementsov-Ogievskiy Message-id: 20170928120300.58164-1-vsementsov@virtuozzo.com Reviewed-by: John Snow Signed-off-by: Max Reitz --- 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