git: 943814893bda - stable/14 - tcp: always set tcp_tun_port to a correct value

From: Gleb Smirnoff <>
Date: Tue, 02 Jan 2024 19:06:46 UTC
The branch stable/14 has been updated by glebius:


commit 943814893bda5d74d8a2cace0a613dd5733c2845
Author:     Gleb Smirnoff <>
AuthorDate: 2023-12-19 19:24:17 +0000
Commit:     Gleb Smirnoff <>
CommitDate: 2024-01-02 19:06:31 +0000

    tcp: always set tcp_tun_port to a correct value
    The tcp_tun_port field that is used to pass port value between UDP
    and TCP in case of tunneling is a generic field that used to pass
    data between network layers.  It can be contaminated on entry, e.g.
    by a VLAN tag set by a NIC driver.  Explicily set it, so that it
    is zeroed out in a normal not-tunneled TCP.  If it contains garbage,
    tcp_twcheck() later can enter wrong block of code and treat the packet
    as incorrectly tunneled one.  On main and stable/14 that will end up
    with sending incorrect responses, but on stable/13 with ipfw(8) and
    pcb-matching rules it may end up in a panic.
    This is a minimal conservative patch to be merged to stable branches.
    Later we may redesign this.
    PR:                     275169
    Reviewed by:            tuexen
    Differential Revision:
    (cherry picked from commit 513f2e2e7180202167ca2963d815d2a4c3ac0af9)
 sys/netinet/tcp_input.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/sys/netinet/tcp_input.c b/sys/netinet/tcp_input.c
index 9f7e42b582c6..512da877846a 100644
--- a/sys/netinet/tcp_input.c
+++ b/sys/netinet/tcp_input.c
@@ -640,6 +640,7 @@ tcp_input_with_port(struct mbuf **mp, int *offp, int proto, uint16_t port)
 	to.to_flags = 0;
+	m->m_pkthdr.tcp_tun_port = port;
 #ifdef INET6
 	if (isipv6) {
 		ip6 = mtod(m, struct ip6_hdr *);