From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001 From: Hanna Reitz Date: Wed, 9 Feb 2022 15:02:54 +0100 Subject: [PATCH] block/nbd: Assert there are no timers when closed Our two timers must not remain armed beyond nbd_clear_bdrvstate(), or they will access freed data when they fire. This patch is separate from the patches that actually fix the issue (HEAD^^ and HEAD^) so that you can run the associated regression iotest (281) on a configuration that reproducibly exposes the bug. Reviewed-by: Vladimir Sementsov-Ogievskiy Signed-off-by: Hanna Reitz [FE: backport (open_timer doesn't exist yet in 6.2.0)] Signed-off-by: Fabian Ebner --- block/nbd.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/block/nbd.c b/block/nbd.c index b8e5a9b4cc..aab20125d8 100644 --- a/block/nbd.c +++ b/block/nbd.c @@ -108,6 +108,9 @@ static void nbd_clear_bdrvstate(BlockDriverState *bs) yank_unregister_instance(BLOCKDEV_YANK_INSTANCE(bs->node_name)); + /* Must not leave timers behind that would access freed data */ + assert(!s->reconnect_delay_timer); + object_unref(OBJECT(s->tlscreds)); qapi_free_SocketAddress(s->saddr); s->saddr = NULL;