From: Kevin Wolf Date: Tue, 11 Feb 2020 09:48:59 +0000 (+0100) Subject: qcow2: Fix qcow2_alloc_cluster_abort() for external data file X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=c3b6658c1a5a3fb24d6c27b2594cf86146f75b22;p=qemu.git qcow2: Fix qcow2_alloc_cluster_abort() for external data file For external data file, cluster allocations return an offset in the data file and are not refcounted. In this case, there is nothing to do for qcow2_alloc_cluster_abort(). Freeing the same offset in the qcow2 file is wrong and causes crashes in the better case or image corruption in the worse case. Signed-off-by: Kevin Wolf Message-Id: <20200211094900.17315-3-kwolf@redhat.com> Signed-off-by: Kevin Wolf --- diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c index 1947f13a2d..78c95dfa16 100644 --- a/block/qcow2-cluster.c +++ b/block/qcow2-cluster.c @@ -1026,8 +1026,11 @@ err: void qcow2_alloc_cluster_abort(BlockDriverState *bs, QCowL2Meta *m) { BDRVQcow2State *s = bs->opaque; - qcow2_free_clusters(bs, m->alloc_offset, m->nb_clusters << s->cluster_bits, - QCOW2_DISCARD_NEVER); + if (!has_data_file(bs)) { + qcow2_free_clusters(bs, m->alloc_offset, + m->nb_clusters << s->cluster_bits, + QCOW2_DISCARD_NEVER); + } } /*