Use a smaller buffer size too peek the receive data. The content

is discarded anyway, the plen variable is a leftover from the -j
jumbo option.
reported by Nan Xiao; OK deraadt@

1 files changed, 4 insertions, 5 deletions

diff --git a/src/usr.bin/nc/netcat.c b/src/usr.bin/nc/netcat.c
index ce55972a7c..f8bd8fa498 100644
--- a/src/usr.bin/nc/netcat.c
+++ b/src/usr.bin/nc/netcat.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: netcat.c,v 1.187 2017/07/15 17:27:39 jsing Exp $ */
+/* $OpenBSD: netcat.c,v 1.188 2017/10/24 17:49:35 bluhm Exp $ */
 /*
  * Copyright (c) 2001 Eric Jackson <ericj@monkey.org>
  * Copyright (c) 2015 Bob Beck.  All rights reserved.
@@ -563,13 +563,12 @@ main(int argc, char *argv[])
                                  * initially to wait for a caller, then use
                                  * the regular functions to talk to the caller.
                                  */
-                                int rv, plen;
-                                char buf[16384];
+                                int rv;
+                                char buf[2048];
                                 struct sockaddr_storage z;
 
                                 len = sizeof(z);
-                                plen = 2048;
-                                rv = recvfrom(s, buf, plen, MSG_PEEK,
+                                rv = recvfrom(s, buf, sizeof(buf), MSG_PEEK,
                                     (struct sockaddr *)&z, &len);
                                 if (rv < 0)
                                         err(1, "recvfrom");