Date: Wed, 29 Apr 2026 14:48:30 +0000 From: Mark Johnston <markj@FreeBSD.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-branches@FreeBSD.org Cc: Kristof Provost <kp@FreeBSD.org> Subject: git: c01d9bcf0cf6 - releng/15.0 - pf: improve SCTP validation Message-ID: <69f21a3e.3b8cd.18254ea7@gitrepo.freebsd.org>
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The branch releng/15.0 has been updated by markj: URL: https://cgit.FreeBSD.org/src/commit/?id=c01d9bcf0cf683a0bd074383339980bcf3862be5 commit c01d9bcf0cf683a0bd074383339980bcf3862be5 Author: Kristof Provost <kp@FreeBSD.org> AuthorDate: 2026-04-26 09:34:55 +0000 Commit: Mark Johnston <markj@FreeBSD.org> CommitDate: 2026-04-28 19:27:11 +0000 pf: improve SCTP validation As per RFC5061 "4.2. New Parameter Types" the add/delete IP address parameters (0xc001, 0xc002) may not be present in an INIT or INIT-ACK chunk. They are only allowed to be present in an ASCONF chunk. This also prevents unbounded recursion while parsing an SCTP packet. Approved by: so Security: FreeBSD-SA-26:14.pf Security: CVE-2026-7164 PR: 294799 Reported by: Igor Gabriel Sousa e Souza Sponsored by: Orange Business Services --- sys/netpfil/pf/pf.c | 16 +++++--- tests/sys/netpfil/pf/sctp.py | 90 ++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 101 insertions(+), 5 deletions(-) diff --git a/sys/netpfil/pf/pf.c b/sys/netpfil/pf/pf.c index af0629397ea0..3c0505b250e9 100644 --- a/sys/netpfil/pf/pf.c +++ b/sys/netpfil/pf/pf.c @@ -7664,7 +7664,7 @@ again: } static int -pf_multihome_scan(int start, int len, struct pf_pdesc *pd, int op) +pf_multihome_scan(int start, int len, struct pf_pdesc *pd, int op, bool asconf) { int off = 0; struct pf_sctp_multihome_job *job; @@ -7769,13 +7769,16 @@ pf_multihome_scan(int start, int len, struct pf_pdesc *pd, int op) int ret; struct sctp_asconf_paramhdr ah; + if (asconf) + return (PF_DROP); + if (!pf_pull_hdr(pd->m, start + off, &ah, sizeof(ah), NULL, NULL, pd->af)) return (PF_DROP); ret = pf_multihome_scan(start + off + sizeof(ah), ntohs(ah.ph.param_length) - sizeof(ah), pd, - SCTP_ADD_IP_ADDRESS); + SCTP_ADD_IP_ADDRESS, true); if (ret != PF_PASS) return (ret); break; @@ -7784,12 +7787,15 @@ pf_multihome_scan(int start, int len, struct pf_pdesc *pd, int op) int ret; struct sctp_asconf_paramhdr ah; + if (asconf) + return (PF_DROP); + if (!pf_pull_hdr(pd->m, start + off, &ah, sizeof(ah), NULL, NULL, pd->af)) return (PF_DROP); ret = pf_multihome_scan(start + off + sizeof(ah), ntohs(ah.ph.param_length) - sizeof(ah), pd, - SCTP_DEL_IP_ADDRESS); + SCTP_DEL_IP_ADDRESS, true); if (ret != PF_PASS) return (ret); break; @@ -7810,7 +7816,7 @@ pf_multihome_scan_init(int start, int len, struct pf_pdesc *pd) start += sizeof(struct sctp_init_chunk); len -= sizeof(struct sctp_init_chunk); - return (pf_multihome_scan(start, len, pd, SCTP_ADD_IP_ADDRESS)); + return (pf_multihome_scan(start, len, pd, SCTP_ADD_IP_ADDRESS, false)); } int @@ -7819,7 +7825,7 @@ pf_multihome_scan_asconf(int start, int len, struct pf_pdesc *pd) start += sizeof(struct sctp_asconf_chunk); len -= sizeof(struct sctp_asconf_chunk); - return (pf_multihome_scan(start, len, pd, SCTP_ADD_IP_ADDRESS)); + return (pf_multihome_scan(start, len, pd, SCTP_ADD_IP_ADDRESS, false)); } int diff --git a/tests/sys/netpfil/pf/sctp.py b/tests/sys/netpfil/pf/sctp.py index f492f26b63a1..722f7777a305 100644 --- a/tests/sys/netpfil/pf/sctp.py +++ b/tests/sys/netpfil/pf/sctp.py @@ -551,6 +551,96 @@ class TestSCTP(VnetTestTemplate): assert re.search(r"epair.*sctp 192.0.2.1:.*192.0.2.3:1234", states) assert re.search(r"epair.*sctp 192.0.2.1:.*192.0.2.2:1234", states) +class TestSCTP_SRV(VnetTestTemplate): + REQUIRED_MODULES = ["sctp", "pf"] + TOPOLOGY = { + "vnet1": {"ifaces": ["if1"]}, + "vnet2": {"ifaces": ["if1"]}, + "if1": {"prefixes4": [("192.0.2.1/24", "192.0.2.2/24")]}, + } + + def vnet2_handler(self, vnet): + ToolsHelper.print_output("/sbin/pfctl -e") + ToolsHelper.pf_rules([ + "set state-policy if-bound", + "pass inet proto sctp", + "pass on lo"]) + + # Start an SCTP server process, pipe the ppid + data back to the other vnet? + srv = SCTPServer(socket.AF_INET, port=1234) + while True: + srv.accept(vnet) + + @pytest.mark.require_user("root") + @pytest.mark.require_progs(["scapy"]) + def test_initiate_tag_check(self): + # Ensure we don't send ABORTs in response to the other end's INIT_ACK + # That'd interfere with our test. + ToolsHelper.print_output("/sbin/sysctl net.inet.sctp.blackhole=2") + + import scapy.all as sp + + packet = sp.IP(src="192.0.2.1", dst="192.0.2.2") \ + / sp.SCTP(sport=1234, dport=1234) \ + / sp.SCTPChunkInit(init_tag=1, n_in_streams=1, n_out_streams=1, a_rwnd=1500) + packet.show() + + r = sp.sr1(packet, timeout=3) + assert r + r.show() + assert r.getlayer(sp.SCTP) + assert r.getlayer(sp.SCTPChunkInitAck) + assert r.getlayer(sp.SCTP).tag == 1 + + # Send another INIT with the same initiate tag, expect another init ack + packet = sp.IP(src="192.0.2.1", dst="192.0.2.2") \ + / sp.SCTP(sport=1234, dport=1234) \ + / sp.SCTPChunkInit(init_tag=1, n_in_streams=1, n_out_streams=1, a_rwnd=1500) + packet.show() + + r = sp.sr1(packet, timeout=3) + assert r + r.show() + assert r.getlayer(sp.SCTP) + assert r.getlayer(sp.SCTPChunkInitAck) + assert r.getlayer(sp.SCTP).tag == 1 + + # Send an INIT with a different initiate tag, expect another init ack + packet = sp.IP(src="192.0.2.1", dst="192.0.2.2") \ + / sp.SCTP(sport=1234, dport=1234) \ + / sp.SCTPChunkInit(init_tag=42, n_in_streams=1, n_out_streams=1, a_rwnd=1500) + packet.show() + + r = sp.sr1(packet, timeout=3) + assert r + r.show() + assert r.getlayer(sp.SCTP) + assert r.getlayer(sp.SCTPChunkInitAck) + assert r.getlayer(sp.SCTP).tag == 42 + + @pytest.mark.require_user("root") + @pytest.mark.require_progs(["scapy"]) + def test_too_many_add_ip(self): + import scapy.all as sp + DEPTH=90 + params=[] + for i in range(0, DEPTH): + ch = sp.SCTPChunkParamAddIPAddr(len=(DEPTH - i) * 8) + params.append(ch) + packet = sp.IP(src="192.0.2.1", dst="192.0.2.2") \ + / sp.SCTP(sport=4321, dport=1234) \ + / sp.SCTPChunkInit(init_tag=1, n_in_streams=1, n_out_streams=1, a_rwnd=1500, + params=params) + packet.show() + sp.hexdump(packet) + print("len %d" % len(packet)) + + r = sp.sr1(packet, timeout=3) + # We should not get a reply to this + if r: + r.show() + assert not r + class TestSCTPv6(VnetTestTemplate): REQUIRED_MODULES = ["sctp", "pf"] TOPOLOGY = {home | help
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