Re: [PATCH] NFSD: fix decode_cb_sequence4resok

[Benny Halevy <bhalevy@panasas.com>]

On 2011-02-23 08:48, Chuck Lever wrote:
> 
> On Feb 22, 2011, at 2:43 PM, Benny Halevy wrote:
> 
>> Fix bug introduced in patch
>> 85a56480 NFSD: Update XDR decoders in NFSv4 callback client
>>
>> Although decode_cb_sequence4resok ignores highest slotid and target highest slotid
>> it must account for their space in their xdr stream when calling xdr_inline_decode
> 
> The real problem is that decoding for the next operation in the compound will start too early in the buffer, because we didn't account for the ignored 8 bytes here, yes?

Right on the spot.

Benny

> 
> Reviewed-by: Chuck Lever <chuck.lever@oracle.com>
> 
>> Cc: Chuck Lever <chuck.lever@oracle.com>
>> Signed-off-by: Benny Halevy <bhalevy@panasas.com>
>> ---
>> fs/nfsd/nfs4callback.c |    2 +-
>> 1 files changed, 1 insertions(+), 1 deletions(-)
>>
>> diff --git a/fs/nfsd/nfs4callback.c b/fs/nfsd/nfs4callback.c
>> index da54498..d046bdb 100644
>> --- a/fs/nfsd/nfs4callback.c
>> +++ b/fs/nfsd/nfs4callback.c
>> @@ -592,7 +592,7 @@ static int decode_cb_sequence4resok(struct xdr_stream *xdr,
>> 	 * If the server returns different values for sessionID, slotID or
>> 	 * sequence number, the server is looney tunes.
>> 	 */
>> -	p = xdr_inline_decode(xdr, NFS4_MAX_SESSIONID_LEN + 4 + 4);
>> +	p = xdr_inline_decode(xdr, NFS4_MAX_SESSIONID_LEN + 4 + 4 + 4 + 4);
>> 	if (unlikely(p == NULL))
>> 		goto out_overflow;
>> 	memcpy(id.data, p, NFS4_MAX_SESSIONID_LEN);
>> -- 
>> 1.7.3.4
>>
> 
> --
> Chuck Lever
> chuck[dot]lever[at]oracle[dot]com
> 
> 
>