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[Qemu-devel] Re: [PATCH] qcow2 corruption: Fix alloc_cluster_link_l2
From: |
Gleb Natapov |
Subject: |
[Qemu-devel] Re: [PATCH] qcow2 corruption: Fix alloc_cluster_link_l2 |
Date: |
Wed, 15 Apr 2009 13:05:20 +0300 |
On Wed, Apr 15, 2009 at 11:52:31AM +0200, Kevin Wolf wrote:
> 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 $(seq 1 10); do
> qemu-system-x86_64 -hda test.qcow -monitor stdio > /dev/null 2>&1 <<EOF
> savevm test-$i
> quit
> EOF
> done
>
> Signed-off-by: Kevin Wolf <address@hidden>
Acked-by: Gleb Natapov <address@hidden>
> ---
> block-qcow2.c | 2 +-
> 1 files changed, 1 insertions(+), 1 deletions(-)
>
> diff --git a/block-qcow2.c b/block-qcow2.c
> index da8fb42..985214f 100644
> --- a/block-qcow2.c
> +++ b/block-qcow2.c
> @@ -1007,7 +1007,7 @@ static int alloc_cluster_link_l2(BlockDriverState *bs,
> uint64_t cluster_offset,
> 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:
> --
> 1.6.0.6
--
Gleb.