From: Vladimir Sementsov-Ogievskiy Date: Sat, 24 Aug 2019 10:07:40 +0000 (+0300) Subject: block: fix permission update in bdrv_replace_node X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=b503de619ed462cd433187db60719f98fab470c2;p=qemu.git block: fix permission update in bdrv_replace_node It's wrong to OR shared permissions. It may lead to crash on further permission updates. Also, no needs to consider previously calculated permissions, as at this point we already bind all new parents and bdrv_get_cumulative_perm result is enough. So fix the bug by just set permissions by bdrv_get_cumulative_perm result. Bug was introduced in long ago 234ac1a9025, in 2.9. Signed-off-by: Vladimir Sementsov-Ogievskiy Message-id: 20190824100740.61635-1-vsementsov@virtuozzo.com Signed-off-by: Max Reitz --- diff --git a/block.c b/block.c index 874a29a983..5944124845 100644 --- a/block.c +++ b/block.c @@ -4165,7 +4165,6 @@ void bdrv_replace_node(BlockDriverState *from, BlockDriverState *to, { BdrvChild *c, *next; GSList *list = NULL, *p; - uint64_t old_perm, old_shared; uint64_t perm = 0, shared = BLK_PERM_ALL; int ret; @@ -4211,8 +4210,8 @@ void bdrv_replace_node(BlockDriverState *from, BlockDriverState *to, bdrv_unref(from); } - bdrv_get_cumulative_perm(to, &old_perm, &old_shared); - bdrv_set_perm(to, old_perm | perm, old_shared | shared); + bdrv_get_cumulative_perm(to, &perm, &shared); + bdrv_set_perm(to, perm, shared); out: g_slist_free(list);