From: Max Reitz <mreitz@redhat.com>
To: Alberto Garcia <berto@igalia.com>, qemu-devel@nongnu.org
Cc: qemu-block@nongnu.org, Kevin Wolf <kwolf@redhat.com>,
Thomas Huth <thuth@redhat.com>,
"R . Nageswara Sastry" <nasastry@in.ibm.com>
Subject: Re: [Qemu-devel] [PATCH 3/4] qcow2: Don't open images with header.refcount_table_clusters == 0
Date: Thu, 2 Nov 2017 18:41:44 +0100 [thread overview]
Message-ID: <6e9b5351-b1b4-4df4-c267-a8b4e8061864@redhat.com> (raw)
In-Reply-To: <33492fad2f21dff38a33a96decb38983aee7e405.1509550787.git.berto@igalia.com>
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On 2017-11-01 16:42, Alberto Garcia wrote:
> qcow2_do_open() is checking that header.refcount_table_clusters is not
> too large, but it doesn't check that it's greater than zero. Apart
> from the fact that an image like that is obviously corrupted, trying
> to use it crashes QEMU since we end up with a null s->refcount_table
> after qcow2_refcount_init().
>
> These images can however be repaired, so allow opening them if the
> BDRV_O_CHECK flag is set.
>
> Signed-off-by: Alberto Garcia <berto@igalia.com>
> ---
> block/qcow2.c | 6 ++++++
> tests/qemu-iotests/060 | 7 +++++++
> tests/qemu-iotests/060.out | 5 +++++
> 3 files changed, 18 insertions(+)
Reviewed-by: Max Reitz <mreitz@redhat.com>
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next prev parent reply other threads:[~2017-11-02 17:41 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-11-01 15:42 [Qemu-devel] [PATCH 0/4] Misc qcow2 corruption checks Alberto Garcia
2017-11-01 15:42 ` [Qemu-devel] [PATCH 1/4] qcow2: Prevent allocating refcount blocks at offset 0 Alberto Garcia
2017-11-02 17:28 ` Max Reitz
2017-11-03 9:04 ` Alberto Garcia
2017-11-01 15:42 ` [Qemu-devel] [PATCH 2/4] qcow2: Prevent allocating L2 tables " Alberto Garcia
2017-11-02 17:31 ` Max Reitz
2017-11-03 9:56 ` Alberto Garcia
2017-11-01 15:42 ` [Qemu-devel] [PATCH 3/4] qcow2: Don't open images with header.refcount_table_clusters == 0 Alberto Garcia
2017-11-02 17:41 ` Max Reitz [this message]
2017-11-01 15:42 ` [Qemu-devel] [PATCH 4/4] qcow2: Add iotest for an empty refcount table Alberto Garcia
2017-11-02 17:43 ` Max Reitz
2017-11-02 17:24 ` [Qemu-devel] [PATCH 0/4] Misc qcow2 corruption checks Max Reitz
2017-11-03 12:32 ` Alberto Garcia
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