sunrpc: fix loop in gss seqno cache

There was a silly bug in the initial implementation where a loop
variable was not incremented. This commit increments the loop variable.

This bug is somewhat tricky to catch because it can only happen on loops
of two or more. If it is hit, it locks up a kernel thread in an infinite
loop.

Signed-off-by: Nikhil Jha <njha@janestreet.com>
Tested-by: Nikhil Jha <njha@janestreet.com>
Fixes: 08d6ee6d8a10 ("sunrpc: implement rfc2203 rpcsec_gss seqnum cache")
Reviewed-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Anna Schumaker <anna.schumaker@oracle.com>

diff --git a/net/sunrpc/auth_gss/auth_gss.c b/net/sunrpc/auth_gss/auth_gss.c
index 0fa244f16876f3c434fd507b4d53c5eefd748ce4..7b943fbafcc38ba79a685589d696017e8cdc694a 100644 (file)
--- a/net/sunrpc/auth_gss/auth_gss.c
+++ b/net/sunrpc/auth_gss/auth_gss.c
@@ -1724,7 +1724,7 @@ gss_validate(struct rpc_task *task, struct xdr_stream *xdr)
        maj_stat = gss_validate_seqno_mic(ctx, task->tk_rqstp->rq_seqnos[0], seq, p, len);
        /* RFC 2203 5.3.3.1 - compute the checksum of each sequence number in the cache */
        while (unlikely(maj_stat == GSS_S_BAD_SIG && i < task->tk_rqstp->rq_seqno_count))
-               maj_stat = gss_validate_seqno_mic(ctx, task->tk_rqstp->rq_seqnos[i], seq, p, len);
+               maj_stat = gss_validate_seqno_mic(ctx, task->tk_rqstp->rq_seqnos[i++], seq, p, len);
        if (maj_stat == GSS_S_CONTEXT_EXPIRED)
                clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
        if (maj_stat)