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From: Stefan Hajnoczi <stefanha@gmail.com>
To: Max Reitz <mreitz@redhat.com>
Cc: Kevin Wolf <kwolf@redhat.com>,
	qemu-devel@nongnu.org, Stefan Hajnoczi <stefanha@redhat.com>
Subject: Re: [Qemu-devel] [PATCH] qcow2: Fix alloc_clusters_noref() overflow detection
Date: Mon, 5 May 2014 14:22:00 +0200	[thread overview]
Message-ID: <20140505122200.GF16173@stefanha-thinkpad.redhat.com> (raw)
In-Reply-To: <1399174300-27583-1-git-send-email-mreitz@redhat.com>

On Sun, May 04, 2014 at 05:31:40AM +0200, Max Reitz wrote:
> If the very first allocation has a length of 0, the free_cluster_index
> is still 0 after the for loop, which means that subtracting one from it
> will underflow and signal an invalid range of clusters by returning
> -EFBIG. However, there is no such range, as its length is 0.
> 
> Fix this by preventing underflows on free_cluster_index during the
> check.
> 
> Signed-off-by: Max Reitz <mreitz@redhat.com>
> ---
>  block/qcow2-refcount.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)

Thanks, applied to my block tree:
https://github.com/stefanha/qemu/commits/block

Stefan

      parent reply	other threads:[~2014-05-05 12:22 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-05-04  3:31 [Qemu-devel] [PATCH] qcow2: Fix alloc_clusters_noref() overflow detection Max Reitz
2014-05-05  9:36 ` Kevin Wolf
2014-05-05 15:51   ` Max Reitz
2014-05-05 12:22 ` Stefan Hajnoczi [this message]

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