From: Alberto Garcia Date: Fri, 3 Nov 2017 14:18:56 +0000 (+0200) Subject: qcow2: Assert that the crypto header does not overlap other metadata X-Git-Tag: qemu-xen-4.11.0-rc1~52^2~13 X-Git-Url: http://xenbits.xensource.com/gitweb?a=commitdiff_plain;h=c9b83e9c23ecb094ddf987c7c37b8f454cb80615;p=qemu-xen.git qcow2: Assert that the crypto header does not overlap other metadata The crypto header is initialized only when QEMU is creating a new image, so there's no chance of this happening on a corrupted image. If QEMU is really trying to allocate the header overlapping other existing metadata sections then this is a serious bug in QEMU itself so let's add an assertion. Signed-off-by: Alberto Garcia Message-id: ae3d77f312fc0c5e0ac2bbd71676c0112eebe2e5.1509718618.git.berto@igalia.com Reviewed-by: Daniel P. Berrange Signed-off-by: Max Reitz --- diff --git a/block/qcow2.c b/block/qcow2.c index defc1fe49f..b3d66a0e88 100644 --- a/block/qcow2.c +++ b/block/qcow2.c @@ -126,6 +126,7 @@ static ssize_t qcow2_crypto_hdr_init_func(QCryptoBlock *block, size_t headerlen, /* Zero fill remaining space in cluster so it has predictable * content in case of future spec changes */ clusterlen = size_to_clusters(s, headerlen) * s->cluster_size; + assert(qcow2_pre_write_overlap_check(bs, 0, ret, clusterlen) == 0); ret = bdrv_pwrite_zeroes(bs->file, ret + headerlen, clusterlen - headerlen, 0);