svn commit: r271666 - head/sys/netinet

[Xin LI]

Author: delphij
Date: Tue Sep 16 09:48:24 2014
New Revision: 271666
URL: http://svnweb.freebsd.org/changeset/base/271666

Log:
  Fix Denial of Service in TCP packet processing.
  
  Submitted by:	glebius
  Security:	FreeBSD-SA-14:19.tcp

Modified:
  head/sys/netinet/tcp_input.c

Modified: head/sys/netinet/tcp_input.c
==============================================================================
--- head/sys/netinet/tcp_input.c	Tue Sep 16 09:22:43 2014	(r271665)
+++ head/sys/netinet/tcp_input.c	Tue Sep 16 09:48:24 2014	(r271666)
@@ -2185,11 +2185,7 @@ tcp_do_segment(struct mbuf *m, struct tc
 
 	todrop = tp->rcv_nxt - th->th_seq;
 	if (todrop > 0) {
-		/*
-		 * If this is a duplicate SYN for our current connection,
-		 * advance over it and pretend and it's not a SYN.
-		 */
-		if (thflags & TH_SYN && th->th_seq == tp->irs) {
+		if (thflags & TH_SYN) {
 			thflags &= ~TH_SYN;
 			th->th_seq++;
 			if (th->th_urp > 1)