Re: [Qemu-devel] [PATCH 2/2] cadence_gem: avoid stack-writing buffer-overrun

[Stefan Weil <sw@weilnetz.de>]

Am 14.05.2012 06:57, schrieb Peter Crosthwaite:
> ACK and Thanks Jim,
>
> Reviewed-by: Peter A.G. Crosthwaite<peter.crosthwaite@petalogix.com>
>
> On Fri, May 11, 2012 at 2:19 AM, Jim Meyering<jim@meyering.net>  wrote:
>    
>> From: Jim Meyering<meyering@redhat.com>
>>
>> Use sizeof(rxbuf)-size (not sizeof(rxbuf-size)) as the number
>> of bytes to clear.  The latter would always clear 4 or 8
>> bytes, possibly writing beyond the end of that stack buffer.
>> Alternatively, depending on the value of the "size" parameter,
>> it could fail to initialize the end of "rxbuf".
>> Spotted by coverity.
>>
>> Signed-off-by: Jim Meyering<meyering@redhat.com>
>> ---
>>   hw/cadence_gem.c | 2 +-
>>   1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/hw/cadence_gem.c b/hw/cadence_gem.c
>> index e2140ae..dbde392 100644
>> --- a/hw/cadence_gem.c
>> +++ b/hw/cadence_gem.c
>> @@ -664,7 +664,7 @@ static ssize_t gem_receive(VLANClientState *nc, const uint8_t *buf, size_t size)
>>           */
>>
>>          memcpy(rxbuf, buf, size);
>> -        memset(rxbuf + size, 0, sizeof(rxbuf - size));
>> +        memset(rxbuf + size, 0, sizeof(rxbuf) - size);
>>          rxbuf_ptr = rxbuf;
>>          crc_val = cpu_to_le32(crc32(0, rxbuf, MAX(size, 60)));
>>          if (size<  60) {
>> --
>> 1.7.10.1.487.ga3935e6
>>      


Ping. This patch is still missing in 1.1 and master.