According to RFC5661, 18.36.3,
"if the client selects a value for ca_maxresponsesize such that
a replier on a channel could never send a response,the server
SHOULD return NFS4ERR_TOOSMALL in the CREATE_SESSION reply."
This patch let server error out when client sets maxreq_sz less than
SEQUENCE request size, and maxresp_sz less than a SEQUENCE reply size.
Signed-off-by: Mi Jinlong <mijinlong@xxxxxxxxxxxxxx>
---
fs/nfsd/nfs4xdr.c | 26 +++++++++++++++++++++++++-
1 files changed, 25 insertions(+), 1 deletions(-)
diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
index 9901811..bece272 100644
--- a/fs/nfsd/nfs4xdr.c
+++ b/fs/nfsd/nfs4xdr.c
@@ -1135,11 +1135,25 @@ nfsd4_decode_create_session(struct nfsd4_compoundargs *argp,
{
DECODE_HEAD;
- u32 dummy;
+ struct xdr_buf *xb = &argp->rqstp->rq_arg;
+ u32 dummy, minreqlen = 0, minresplen = 0;
char *machine_name;
int i;
int nr_secflavs;
+ /* RPC header length and tag, minorversion, Opt count*/
+ minreqlen = (char *)argp->p - ((char *)argp->end - xb->len);
+ /* length with a SEQUENCE operation */
+ minreqlen = minreqlen + sizeof(struct nfs4_sessionid)
+ + 4 * sizeof(__be32);
+
+ /* RPC header, status, tag len */
+ minresplen = argp->rqstp->rq_res.head[0].iov_len + 2 * sizeof(__be32)
+ /* tag, opt count, opcode, op status */
+ + ALIGN(argp->taglen, 4) + 3 * sizeof(__be32)
+ /* sessionid, seqid, 3 * slotid, status*/
+ + sizeof(struct nfs4_sessionid) + 5 * sizeof(__be32);
+
READ_BUF(16);
COPYMEM(&sess->clientid, 8);
READ32(sess->seqid);
@@ -1149,7 +1163,17 @@ nfsd4_decode_create_session(struct nfsd4_compoundargs *argp,
READ_BUF(28);
READ32(dummy); /* headerpadsz is always 0 */
READ32(sess->fore_channel.maxreq_sz);
+ if (sess->fore_channel.maxreq_sz < minreqlen) {
+ status = nfserr_toosmall;
+ goto out;
+ }
+
READ32(sess->fore_channel.maxresp_sz);
+ if (sess->fore_channel.maxresp_sz < minresplen) {
+ status = nfserr_toosmall;
+ goto out;
+ }
+
READ32(sess->fore_channel.maxresp_cached);
READ32(sess->fore_channel.maxops);
READ32(sess->fore_channel.maxreqs);
--
1.7.5.4
--
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