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.
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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