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author | Kristof Provost <kp@FreeBSD.org> | 2019-03-21 08:09:52 +0000 |
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committer | Kristof Provost <kp@FreeBSD.org> | 2019-03-21 08:09:52 +0000 |
commit | 64af73aadea59c22daf168ff742e8e9f03d2da78 (patch) | |
tree | 211fbd5df419e23d8051acd4b2eb214707150c85 /sys/netpfil/pf/pf.c | |
parent | e77a99c1c15a1d81f9a47c2a7611aa8325662142 (diff) | |
download | src-64af73aadea59c22daf168ff742e8e9f03d2da78.tar.gz src-64af73aadea59c22daf168ff742e8e9f03d2da78.zip |
pf: Ensure that IP addresses match in ICMP error packets
States in pf(4) let ICMP and ICMP6 packets pass if they have a
packet in their payload that matches an exiting connection. It was
not checked whether the outer ICMP packet has the same destination
IP as the source IP of the inner protocol packet. Enforce that
these addresses match, to prevent ICMP packets that do not make
sense.
Reported by: Nicolas Collignon, Corentin Bayet, Eloi Vanderbeken, Luca Moro at Synacktiv
Obtained from: OpenBSD
Security: CVE-2019-5598
Notes
Notes:
svn path=/head/; revision=345366
Diffstat (limited to 'sys/netpfil/pf/pf.c')
-rw-r--r-- | sys/netpfil/pf/pf.c | 25 |
1 files changed, 22 insertions, 3 deletions
diff --git a/sys/netpfil/pf/pf.c b/sys/netpfil/pf/pf.c index 9dc2acec5237..843d989ec6e0 100644 --- a/sys/netpfil/pf/pf.c +++ b/sys/netpfil/pf/pf.c @@ -4594,7 +4594,7 @@ pf_test_state_icmp(struct pf_state **state, int direction, struct pfi_kif *kif, { struct pf_addr *saddr = pd->src, *daddr = pd->dst; u_int16_t icmpid = 0, *icmpsum; - u_int8_t icmptype; + u_int8_t icmptype, icmpcode; int state_icmp = 0; struct pf_state_key_cmp key; @@ -4603,6 +4603,7 @@ pf_test_state_icmp(struct pf_state **state, int direction, struct pfi_kif *kif, #ifdef INET case IPPROTO_ICMP: icmptype = pd->hdr.icmp->icmp_type; + icmpcode = pd->hdr.icmp->icmp_code; icmpid = pd->hdr.icmp->icmp_id; icmpsum = &pd->hdr.icmp->icmp_cksum; @@ -4617,6 +4618,7 @@ pf_test_state_icmp(struct pf_state **state, int direction, struct pfi_kif *kif, #ifdef INET6 case IPPROTO_ICMPV6: icmptype = pd->hdr.icmp6->icmp6_type; + icmpcode = pd->hdr.icmp6->icmp6_code; icmpid = pd->hdr.icmp6->icmp6_id; icmpsum = &pd->hdr.icmp6->icmp6_cksum; @@ -4815,6 +4817,23 @@ pf_test_state_icmp(struct pf_state **state, int direction, struct pfi_kif *kif, #endif /* INET6 */ } + if (PF_ANEQ(pd->dst, pd2.src, pd->af)) { + if (V_pf_status.debug >= PF_DEBUG_MISC) { + printf("pf: BAD ICMP %d:%d outer dst: ", + icmptype, icmpcode); + pf_print_host(pd->src, 0, pd->af); + printf(" -> "); + pf_print_host(pd->dst, 0, pd->af); + printf(" inner src: "); + pf_print_host(pd2.src, 0, pd2.af); + printf(" -> "); + pf_print_host(pd2.dst, 0, pd2.af); + printf("\n"); + } + REASON_SET(reason, PFRES_BADSTATE); + return (PF_DROP); + } + switch (pd2.proto) { case IPPROTO_TCP: { struct tcphdr th; @@ -4871,7 +4890,7 @@ pf_test_state_icmp(struct pf_state **state, int direction, struct pfi_kif *kif, !SEQ_GEQ(seq, src->seqlo - (dst->max_win << dws)))) { if (V_pf_status.debug >= PF_DEBUG_MISC) { printf("pf: BAD ICMP %d:%d ", - icmptype, pd->hdr.icmp->icmp_code); + icmptype, icmpcode); pf_print_host(pd->src, 0, pd->af); printf(" -> "); pf_print_host(pd->dst, 0, pd->af); @@ -4884,7 +4903,7 @@ pf_test_state_icmp(struct pf_state **state, int direction, struct pfi_kif *kif, } else { if (V_pf_status.debug >= PF_DEBUG_MISC) { printf("pf: OK ICMP %d:%d ", - icmptype, pd->hdr.icmp->icmp_code); + icmptype, icmpcode); pf_print_host(pd->src, 0, pd->af); printf(" -> "); pf_print_host(pd->dst, 0, pd->af); |