From: Kevin Wolf <kwolf@redhat.com>

To: qemu-devel@nongnu.org

Subject: [Qemu-devel] [PATCH] qcow2 corruption: Fix alloc_cluster_link_l2

This patch fixes a qcow2 corruption bug introduced in SVN Rev 5861. L2 tables

are big endian, so entries must be converted before being passed to functions.

This bug is easy to trigger. The following script will create and destroy a

qcow2 image (the header is gone after three loop iterations):

    #!/bin/bash

    qemu-img create -f qcow2 test.qcow 1M

    for i in $(seq 1 10); do

    qemu-system-x86_64 -hda test.qcow -monitor stdio > /dev/null 2>&1 <

    savevm test-$i

    quit

    EOF

    done

Signed-off-by: Kevin Wolf <kwolf@redhat.com>

---

 block-qcow2.c |    2 +-

 1 files changed, 1 insertions(+), 1 deletions(-)

diff -up qemu-kvm-0.10/qemu/block-qcow2.c.qcow2-corruption qemu-kvm-0.10/qemu/block-qcow2.c

--- qemu-kvm-0.10/qemu/block-qcow2.c.qcow2-corruption	2009-04-20 14:41:22.000000000 +0100

+++ qemu-kvm-0.10/qemu/block-qcow2.c	2009-04-20 14:41:54.000000000 +0100

@@ -912,7 +912,7 @@ static int alloc_cluster_link_l2(BlockDr

         goto err;

     for (i = 0; i < j; i++)

-        free_any_clusters(bs, old_cluster[i], 1);

+        free_any_clusters(bs, be64_to_cpu(old_cluster[i]), 1);

     ret = 0;

 err: