The branch stable/13 has been updated by tuexen: URL: https://cgit.FreeBSD.org/src/commit/?id=eb91abb4ba3dbdafedfea125129b2f0115e81137
commit eb91abb4ba3dbdafedfea125129b2f0115e81137 Author: Randall Stewart <[email protected]> AuthorDate: 2021-05-27 14:50:32 +0000 Commit: Michael Tuexen <[email protected]> CommitDate: 2021-06-09 00:18:36 +0000 tcp: When we have an out-of-order FIN we do want to strip off the FIN bit. The last set of commits fixed both a panic (in rack) and an ACK-war (in freebsd and bbr). However there was a missing case, i.e. where we get an out-of-order FIN by itself. In such a case we don't want to leave the FIN bit set, otherwise we will do the wrong thing and ack the FIN incorrectly. Instead we need to go through the tcp_reasm() code and that way the FIN will be stripped and all will be well. Reviewed by: mtuexen,rscheff Sponsored by: Netflix Inc Differential Revision: https://reviews.freebsd.org/D30497 (cherry picked from commit 8c69d988a8d32e53310c7b73ec8721b04b7249e6) --- sys/netinet/tcp_input.c | 7 ++++++- sys/netinet/tcp_stacks/bbr.c | 7 ++++++- sys/netinet/tcp_stacks/rack.c | 7 ++++++- 3 files changed, 18 insertions(+), 3 deletions(-) diff --git a/sys/netinet/tcp_input.c b/sys/netinet/tcp_input.c index 4ea0f7c5231c..b6a198b49eef 100644 --- a/sys/netinet/tcp_input.c +++ b/sys/netinet/tcp_input.c @@ -3184,7 +3184,12 @@ dodata: /* XXX */ * when trimming from the head. */ tcp_seq temp = save_start; - if (tlen) { + if (tlen || (th->th_seq != tp->rcv_nxt)) { + /* + * We add the th_seq != rcv_nxt to + * catch the case of a stand alone out + * of order FIN. + */ thflags = tcp_reass(tp, th, &temp, &tlen, m); tp->t_flags |= TF_ACKNOW; } diff --git a/sys/netinet/tcp_stacks/bbr.c b/sys/netinet/tcp_stacks/bbr.c index 78957bdfb27d..a10235f94c89 100644 --- a/sys/netinet/tcp_stacks/bbr.c +++ b/sys/netinet/tcp_stacks/bbr.c @@ -8321,7 +8321,12 @@ bbr_process_data(struct mbuf *m, struct tcphdr *th, struct socket *so, * trimming from the head. */ tcp_seq temp = save_start; - if (tlen) { + if (tlen || (th->th_seq != tp->rcv_nxt)) { + /* + * We add the th_seq != rcv_nxt to + * catch the case of a stand alone out + * of order FIN. + */ thflags = tcp_reass(tp, th, &temp, &tlen, m); tp->t_flags |= TF_ACKNOW; } diff --git a/sys/netinet/tcp_stacks/rack.c b/sys/netinet/tcp_stacks/rack.c index 5556e562c0eb..63574691112c 100644 --- a/sys/netinet/tcp_stacks/rack.c +++ b/sys/netinet/tcp_stacks/rack.c @@ -10236,7 +10236,12 @@ rack_process_data(struct mbuf *m, struct tcphdr *th, struct socket *so, * trimming from the head. */ tcp_seq temp = save_start; - if (tlen) { + if (tlen || (th->th_seq != tp->rcv_nxt)) { + /* + * We add the th_seq != rcv_nxt to + * catch the case of a stand alone out + * of order FIN. + */ thflags = tcp_reass(tp, th, &temp, &tlen, m); tp->t_flags |= TF_ACKNOW; } _______________________________________________ [email protected] mailing list https://lists.freebsd.org/mailman/listinfo/dev-commits-src-all To unsubscribe, send any mail to "[email protected]"
