Re: [Qemu-devel] [PATCH] scsi-disk: fix buffer overflow

From: Anthony Liguori <anthony@codemonkey.ws>
To: Gerd Hoffmann <kraxel@redhat.com>
Cc: qemu-devel@nongnu.org
Subject: Re: [Qemu-devel] [PATCH] scsi-disk: fix buffer overflow
Date: Wed, 17 Mar 2010 11:59:20 -0500	[thread overview]
Message-ID: <4BA10A68.2060607@codemonkey.ws> (raw)
In-Reply-To: <1268239637-24524-1-git-send-email-kraxel@redhat.com>

On 03/10/2010 10:47 AM, Gerd Hoffmann wrote:
> In case s->version is shorter than 4 bytes we overflow the memcpy src
> buffer.  Fix it by clearing the target buffer, then copy only the
> amount of bytes we actually have.
>
> Signed-off-by: Gerd Hoffmann<kraxel@redhat.com>
>    

Applied.  Thanks.

Regards,

Anthony Liguori
> ---
>   hw/scsi-disk.c |    4 +++-
>   1 files changed, 3 insertions(+), 1 deletions(-)
>
> diff --git a/hw/scsi-disk.c b/hw/scsi-disk.c
> index b2f61fe..5792545 100644
> --- a/hw/scsi-disk.c
> +++ b/hw/scsi-disk.c
> @@ -459,7 +459,9 @@ static int scsi_disk_emulate_inquiry(SCSIRequest *req, uint8_t *outbuf)
>           memcpy(&outbuf[16], "QEMU HARDDISK   ", 16);
>       }
>       memcpy(&outbuf[8], "QEMU    ", 8);
> -    memcpy(&outbuf[32], s->version ? s->version : QEMU_VERSION, 4);
> +    memset(&outbuf[32], 0, 4);
> +    memcpy(&outbuf[32], s->version ? s->version : QEMU_VERSION,
> +           MIN(4, strlen(s->version ? s->version : QEMU_VERSION)));
>       /* Identify device as SCSI-3 rev 1.
>          Some later commands are also implemented. */
>       outbuf[2] = 5;
>    