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Re: [Qemu-devel] [PATCH v4 05/10] qcow2: Fix refcount blocks beyond imag
From: |
Eric Blake |
Subject: |
Re: [Qemu-devel] [PATCH v4 05/10] qcow2: Fix refcount blocks beyond image end |
Date: |
Fri, 29 Aug 2014 13:50:33 -0600 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.7.0 |
On 08/27/2014 02:18 PM, Max Reitz wrote:
> If the qcow2 check function detects a refcount block located beyond the
> image end, grow the image appropriately. This cannot break anything and
> is the logical fix for such a case.
>
> Signed-off-by: Max Reitz <address@hidden>
> ---
> block/qcow2-refcount.c | 62
> ++++++++++++++++++++++++++++++++++++++++++++++----
> 1 file changed, 58 insertions(+), 4 deletions(-)
>
> diff --git a/block/qcow2-refcount.c b/block/qcow2-refcount.c
> index babe6cb..394a402 100644
> --- a/block/qcow2-refcount.c
> +++ b/block/qcow2-refcount.c
> @@ -1505,7 +1505,8 @@ static int check_refblocks(BlockDriverState *bs,
> BdrvCheckResult *res,
> int64_t *nb_clusters)
> {
> BDRVQcowState *s = bs->opaque;
> - int64_t i;
> + int64_t i, size;
> + int ret;
>
> for(i = 0; i < s->refcount_table_size; i++) {
Is it worth fixing up the whitespace on this 'for' at any point in the
series?
> + if (fix & BDRV_FIX_ERRORS) {
> + int64_t old_nb_clusters = *nb_clusters;
> +
> + if (offset + s->cluster_size < offset ||
> + offset + s->cluster_size > INT64_MAX)
[1]
> +
> + *refcount_table = g_try_realloc(*refcount_table,
> + *nb_clusters * sizeof(uint16_t));
I was about to complain that this multiply could overflow if
*nb_clusters is more than 2**62 bits, until I double checked that due to
the limit checking at [1], we know *nb_clusters is narrower.
Reviewed-by: Eric Blake <address@hidden>
--
Eric Blake eblake redhat com +1-919-301-3266
Libvirt virtualization library http://libvirt.org
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- [Qemu-devel] [PATCH v4 00/10] qcow2: Fix image repairing, Max Reitz, 2014/08/27
- [Qemu-devel] [PATCH v4 01/10] qcow2: Fix leaks in dirty images, Max Reitz, 2014/08/27
- [Qemu-devel] [PATCH v4 02/10] qcow2: Split qcow2_check_refcounts(), Max Reitz, 2014/08/27
- [Qemu-devel] [PATCH v4 03/10] qcow2: Pull check_refblocks() up, Max Reitz, 2014/08/27
- [Qemu-devel] [PATCH v4 04/10] qcow2: Reuse refcount table in calculate_refcounts(), Max Reitz, 2014/08/27
- [Qemu-devel] [PATCH v4 05/10] qcow2: Fix refcount blocks beyond image end, Max Reitz, 2014/08/27
- Re: [Qemu-devel] [PATCH v4 05/10] qcow2: Fix refcount blocks beyond image end,
Eric Blake <=
- [Qemu-devel] [PATCH v4 06/10] qcow2: Do not perform potentially damaging repairs, Max Reitz, 2014/08/27
- [Qemu-devel] [PATCH v4 07/10] qcow2: Rebuild refcount structure during check, Max Reitz, 2014/08/27
- [Qemu-devel] [PATCH v4 08/10] qcow2: Clean up after refcount rebuild, Max Reitz, 2014/08/27
- [Qemu-devel] [PATCH v4 09/10] iotests: Fix test outputs, Max Reitz, 2014/08/27
- [Qemu-devel] [PATCH v4 10/10] iotests: Add test for potentially damaging repairs, Max Reitz, 2014/08/27