Date: Sat, 10 Apr 2010 00:14:50 +0200
From: Aurelien Jarno <aurelien@aurel32.net>
Subject: Re: [Qemu-devel] [PATCH] block: Fix multiwrite error handling
Message-ID: <20100409221450.GN21042@volta.aurel32.net>
References: <1270154924-10400-1-git-send-email-kwolf@redhat.com>
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In-Reply-To: <1270154924-10400-1-git-send-email-kwolf@redhat.com>
To: Kevin Wolf <kwolf@redhat.com>
Cc: qemu-devel@nongnu.org

On Thu, Apr 01, 2010 at 10:48:44PM +0200, Kevin Wolf wrote:
> When two requests of the same multiwrite batch fail, the callback of all
> requests in that batch were called twice. This could have any kind of nasty
> effects, in my case it lead to use after free and eventually a segfault.
> 
> Signed-off-by: Kevin Wolf <kwolf@redhat.com>

Thanks, applied.

> ---
>  block.c |    2 +-
>  1 files changed, 1 insertions(+), 1 deletions(-)
> 
> diff --git a/block.c b/block.c
> index 31610af..1c36e91 100644
> --- a/block.c
> +++ b/block.c
> @@ -1734,7 +1734,7 @@ static void multiwrite_cb(void *opaque, int ret)
>  {
>      MultiwriteCB *mcb = opaque;
>  
> -    if (ret < 0) {
> +    if (ret < 0 && !mcb->error) {
>          mcb->error = ret;
>          multiwrite_user_cb(mcb);
>      }
> -- 
> 1.6.6.1
> 
> 
> 
> 

-- 
Aurelien Jarno                          GPG: 1024D/F1BCDB73
aurelien@aurel32.net                 http://www.aurel32.net