Fix Denial of Service in TCP packet processing.

Submitted by:	glebius
Security:	FreeBSD-SA-14:19.tcp
This commit is contained in:
Xin LI 2014-09-16 09:48:24 +00:00
parent 43f9f175c5
commit 831ad37ef2
Notes: svn2git 2020-12-20 02:59:44 +00:00
svn path=/head/; revision=271666

View File

@ -2185,11 +2185,7 @@ tcp_do_segment(struct mbuf *m, struct tcphdr *th, struct socket *so,
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)