Date: Tue, 19 May 2026 14:57:17 +0000 From: Michael Tuexen <tuexen@FreeBSD.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-branches@FreeBSD.org Subject: git: efd07ee95616 - stable/14 - tcp: improve validation of received TCP over UDP packets Message-ID: <6a0c7a4d.411b3.6c0ff332@gitrepo.freebsd.org>
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The branch stable/14 has been updated by tuexen: URL: https://cgit.FreeBSD.org/src/commit/?id=efd07ee956162648f6ddb4bfe76b702a51ef427b commit efd07ee956162648f6ddb4bfe76b702a51ef427b Author: Michael Tuexen <tuexen@FreeBSD.org> AuthorDate: 2026-02-20 21:21:37 +0000 Commit: Michael Tuexen <tuexen@FreeBSD.org> CommitDate: 2026-05-19 12:55:55 +0000 tcp: improve validation of received TCP over UDP packets Reviewed by: glebius, pouria Sponsored by: Netflix, Inc. Differential Revision: https://reviews.freebsd.org/D55410 (cherry picked from commit e1886559ea477add82a0a86cddf728f6778f1603) --- sys/netinet/tcp_subr.c | 22 +++++++++++++++++----- 1 file changed, 17 insertions(+), 5 deletions(-) diff --git a/sys/netinet/tcp_subr.c b/sys/netinet/tcp_subr.c index e1346b433899..ca201d721616 100644 --- a/sys/netinet/tcp_subr.c +++ b/sys/netinet/tcp_subr.c @@ -626,7 +626,7 @@ tcp_recv_udp_tunneled_packet(struct mbuf *m, int off, struct inpcb *inp, #endif struct udphdr *uh; struct tcphdr *th; - int thlen; + int len, thlen; uint16_t port; TCPSTAT_INC(tcps_tunneled_pkts); @@ -670,15 +670,27 @@ tcp_recv_udp_tunneled_packet(struct mbuf *m, int off, struct inpcb *inp, switch (iph->ip_v) { #ifdef INET case IPVERSION: - iph->ip_len = htons(ntohs(iph->ip_len) - sizeof(struct udphdr)); - tcp_input_with_port(&m, &off, IPPROTO_TCP, port); + len = ntohs(iph->ip_len) - sizeof(struct udphdr); + if (len != m->m_pkthdr.len) { + TCPSTAT_INC(tcps_tunneled_errs); + goto out; + } else { + iph->ip_len = htons(len); + tcp_input_with_port(&m, &off, IPPROTO_TCP, port); + } break; #endif #ifdef INET6 case IPV6_VERSION >> 4: ip6 = mtod(m, struct ip6_hdr *); - ip6->ip6_plen = htons(ntohs(ip6->ip6_plen) - sizeof(struct udphdr)); - tcp6_input_with_port(&m, &off, IPPROTO_TCP, port); + len = ntohs(ip6->ip6_plen) - sizeof(struct udphdr); + if (len + sizeof(struct ip6_hdr) != m->m_pkthdr.len) { + TCPSTAT_INC(tcps_tunneled_errs); + goto out; + } else { + ip6->ip6_plen = htons(len); + tcp6_input_with_port(&m, &off, IPPROTO_TCP, port); + } break; #endif default:home | help
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