svcrpc: close connection if client sends short packet
If the client sents a record too short to contain even the beginning of
the rpc header, then just close the connection.
The current code drops the record data and continues. I don't see the
point. It's a hopeless situation and simpler just to cut off the
connection completely.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
diff --git a/net/sunrpc/svcsock.c b/net/sunrpc/svcsock.c
index 1955e1a..62ff7c5 100644
--- a/net/sunrpc/svcsock.c
+++ b/net/sunrpc/svcsock.c
@@ -955,6 +955,9 @@
}
}
+ if (svsk->sk_reclen < 8)
+ goto err_delete; /* client is nuts. */
+
/* Check whether enough data is available */
len = svc_recv_available(svsk);
if (len < 0)
@@ -1058,20 +1061,10 @@
vec[0] = rqstp->rq_arg.head[0];
vlen = PAGE_SIZE;
- /*
- * We have enough data for the whole tcp record. Let's try and read the
- * first 8 bytes to get the xid and the call direction. We can use this
- * to figure out if this is a call or a reply to a callback. If
- * sk_reclen is < 8 (xid and calldir), then this is a malformed packet.
- * In that case, don't bother with the calldir and just read the data.
- * It will be rejected in svc_process.
- */
- if (len >= 8) {
- len = svc_process_calldir(svsk, rqstp, &req, vec);
- if (len < 0)
- goto err_again;
- vlen -= 8;
- }
+ len = svc_process_calldir(svsk, rqstp, &req, vec);
+ if (len < 0)
+ goto err_again;
+ vlen -= 8;
pnum = 1;
while (vlen < svsk->sk_reclen - 8) {