diff options
| author | Kristof Provost <kp@FreeBSD.org> | 2026-04-26 09:34:55 +0000 |
|---|---|---|
| committer | Mark Johnston <markj@FreeBSD.org> | 2026-04-29 14:39:28 +0000 |
| commit | 6f9ddb329b07099e392c78b6e4fef1c6252de0dc (patch) | |
| tree | fabf200d2d30067df444d0f587ff9b257e5a001a | |
| parent | 5d8e32aad2a8316b0aab8a93a677a63e4c3df422 (diff) | |
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
| -rw-r--r-- | sys/netpfil/pf/pf.c | 16 | ||||
| -rw-r--r-- | tests/sys/netpfil/pf/sctp.py | 23 |
2 files changed, 34 insertions, 5 deletions
diff --git a/sys/netpfil/pf/pf.c b/sys/netpfil/pf/pf.c index 53f74271e268..27d03b688937 100644 --- a/sys/netpfil/pf/pf.c +++ b/sys/netpfil/pf/pf.c @@ -8353,7 +8353,7 @@ 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; @@ -8458,6 +8458,9 @@ 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, pd->af)) return (PF_DROP); @@ -8467,7 +8470,7 @@ pf_multihome_scan(int start, int len, struct pf_pdesc *pd, int op) 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; @@ -8476,6 +8479,9 @@ 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, pd->af)) return (PF_DROP); @@ -8485,7 +8491,7 @@ pf_multihome_scan(int start, int len, struct pf_pdesc *pd, int op) 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; @@ -8506,7 +8512,7 @@ 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 @@ -8515,7 +8521,7 @@ 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 9f1d7dea4ef6..722f7777a305 100644 --- a/tests/sys/netpfil/pf/sctp.py +++ b/tests/sys/netpfil/pf/sctp.py @@ -618,6 +618,29 @@ class TestSCTP_SRV(VnetTestTemplate): 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 = { |