On Mon, Mar 10, 2014 at 11:34:55AM -0400, Jeff Layton wrote:
> We have a WARN_ON in the nfsd4_decode_write() that tells us when the
> client has sent a request that is not padded out properly according to
> RFC4506. A WARN_ON really isn't appropriate in this case though since
> this indicates a client bug, not a server one.
>
> Move this check out to the top-level compound decoder and have it just
> explicitly return an error. Also add a dprintk() that shows the client
> address and xid to help track down clients and frames that trigger it.
OK, thanks.--b.
>
> Signed-off-by: Jeff Layton <jlayton@xxxxxxxxxx>
> ---
> fs/nfsd/nfs4xdr.c | 7 ++++++-
> 1 file changed, 6 insertions(+), 1 deletion(-)
>
> diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
> index 63f2395c57ed..3a491dade169 100644
> --- a/fs/nfsd/nfs4xdr.c
> +++ b/fs/nfsd/nfs4xdr.c
> @@ -1222,7 +1222,6 @@ nfsd4_decode_write(struct nfsd4_compoundargs *argp, struct nfsd4_write *write)
> }
> write->wr_head.iov_base = p;
> write->wr_head.iov_len = avail;
> - WARN_ON(avail != (XDR_QUADLEN(avail) << 2));
> write->wr_pagelist = argp->pagelist;
>
> len = XDR_QUADLEN(write->wr_buflen) << 2;
> @@ -3691,6 +3690,12 @@ int nfsd4_release_compoundargs(void *rq, __be32 *p, void *resp)
> int
> nfs4svc_decode_compoundargs(struct svc_rqst *rqstp, __be32 *p, struct nfsd4_compoundargs *args)
> {
> + if (rqstp->rq_arg.head[0].iov_len % 4) {
> + /* client is nuts */
> + dprintk("%s: compound not properly padded! (peeraddr=%pISc xid=0x%x)",
> + __func__, svc_addr(rqstp), be32_to_cpu(rqstp->rq_xid));
> + return 0;
> + }
> args->p = p;
> args->end = rqstp->rq_arg.head[0].iov_base + rqstp->rq_arg.head[0].iov_len;
> args->pagelist = rqstp->rq_arg.pages;
> --
> 1.8.5.3
>
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