From 63f88319d9f566e28c26c64d5830ea08c46b2b49 Mon Sep 17 00:00:00 2001 From: Michal Ruprich Date: Mon, 18 Dec 2023 15:27:19 +0100 Subject: [PATCH] Resolves: RHEL-15915 - crash from specially crafted MP_UNREACH_NLRI-containing BGP UPDATE message --- .frr.metadata | 2 + 0005-CVE-2023-47235.patch | 110 ++++++++++++++++++++++++++++++++++++++ 0006-CVE-2023-47234.patch | 95 ++++++++++++++++++++++++++++++++ frr.spec | 8 ++- 4 files changed, 214 insertions(+), 1 deletion(-) create mode 100644 .frr.metadata create mode 100644 0005-CVE-2023-47235.patch create mode 100644 0006-CVE-2023-47234.patch diff --git a/.frr.metadata b/.frr.metadata new file mode 100644 index 0000000..6929825 --- /dev/null +++ b/.frr.metadata @@ -0,0 +1,2 @@ +5f46099a744058de374dbbf5240d1c4292a143f2 frr-8.5.3.tar.gz +f9cc2bf16aa26b5090d782b70111f511cb276de1 remove-babeld-ldpd.sh diff --git a/0005-CVE-2023-47235.patch b/0005-CVE-2023-47235.patch new file mode 100644 index 0000000..6d0504b --- /dev/null +++ b/0005-CVE-2023-47235.patch @@ -0,0 +1,110 @@ +From 71422bfe269e34b69d78f9fb02f30426f2fdef48 Mon Sep 17 00:00:00 2001 +From: rpm-build +Date: Wed, 13 Dec 2023 16:59:46 +0100 +Subject: [PATCH] bgpd: Treat EOR as withdrawn to avoid unwanted handling of + malformed attrs + +Treat-as-withdraw, otherwise if we just ignore it, we will pass it to be +processed as a normal UPDATE without mandatory attributes, that could lead +to harmful behavior. In this case, a crash for route-maps with the configuration +such as: + +``` +router bgp 65001 + no bgp ebgp-requires-policy + neighbor 127.0.0.1 remote-as external + neighbor 127.0.0.1 passive + neighbor 127.0.0.1 ebgp-multihop + neighbor 127.0.0.1 disable-connected-check + neighbor 127.0.0.1 update-source 127.0.0.2 + neighbor 127.0.0.1 timers 3 90 + neighbor 127.0.0.1 timers connect 1 + ! + address-family ipv4 unicast + neighbor 127.0.0.1 addpath-tx-all-paths + neighbor 127.0.0.1 default-originate + neighbor 127.0.0.1 route-map RM_IN in + exit-address-family +exit +! +route-map RM_IN permit 10 + set as-path prepend 200 +exit +``` + +Send a malformed optional transitive attribute: + +``` +import socket +import time + +OPEN = (b"\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff" +b"\xff\xff\x00\x62\x01\x04\xfd\xea\x00\x5a\x0a\x00\x00\x01\x45\x02" +b"\x06\x01\x04\x00\x01\x00\x01\x02\x02\x02\x00\x02\x02\x46\x00\x02" +b"\x06\x41\x04\x00\x00\xfd\xea\x02\x02\x06\x00\x02\x06\x45\x04\x00" +b"\x01\x01\x03\x02\x0e\x49\x0c\x0a\x64\x6f\x6e\x61\x74\x61\x73\x2d" +b"\x70\x63\x00\x02\x04\x40\x02\x00\x78\x02\x09\x47\x07\x00\x01\x01" +b"\x80\x00\x00\x00") + +KEEPALIVE = (b"\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff" +b"\xff\xff\xff\xff\xff\xff\x00\x13\x04") + +UPDATE = bytearray.fromhex("ffffffffffffffffffffffffffffffff002b0200000003c0ff00010100eb00ac100b0b001ad908ac100b0b") + +s = socket.socket(socket.AF_INET, socket.SOCK_STREAM) +s.connect(('127.0.0.2', 179)) +s.send(OPEN) +data = s.recv(1024) +s.send(KEEPALIVE) +data = s.recv(1024) +s.send(UPDATE) +data = s.recv(1024) +time.sleep(100) +s.close() +``` + +Reported-by: Iggy Frankovic +Signed-off-by: Donatas Abraitis + +(cherry picked from commit 6814f2e0138a6ea5e1f83bdd9085d9a77999900b) +--- + bgpd/bgp_attr.c | 15 ++++++++++++--- + 1 file changed, 12 insertions(+), 3 deletions(-) + +diff --git a/bgpd/bgp_attr.c b/bgpd/bgp_attr.c +index a121911..12a6953 100644 +--- a/bgpd/bgp_attr.c ++++ b/bgpd/bgp_attr.c +@@ -3079,9 +3079,12 @@ static int bgp_attr_check(struct peer *peer, struct attr *attr) + uint8_t type = 0; + + /* BGP Graceful-Restart End-of-RIB for IPv4 unicast is signaled as an +- * empty UPDATE. */ ++ * empty UPDATE. Treat-as-withdraw, otherwise if we just ignore it, ++ * we will pass it to be processed as a normal UPDATE without mandatory ++ * attributes, that could lead to harmful behavior. ++ */ + if (CHECK_FLAG(peer->cap, PEER_CAP_RESTART_RCV) && !attr->flag) +- return BGP_ATTR_PARSE_PROCEED; ++ return BGP_ATTR_PARSE_WITHDRAW; + + /* "An UPDATE message that contains the MP_UNREACH_NLRI is not required + to carry any other path attributes.", though if MP_REACH_NLRI or NLRI +@@ -3507,7 +3510,13 @@ done: + aspath_unintern(&as4_path); + + transit = bgp_attr_get_transit(attr); +- if (ret != BGP_ATTR_PARSE_ERROR) { ++ /* If we received an UPDATE with mandatory attributes, then ++ * the unrecognized transitive optional attribute of that ++ * path MUST be passed. Otherwise, it's an error, and from ++ * security perspective it might be very harmful if we continue ++ * here with the unrecognized attributes. ++ */ ++ if (ret == BGP_ATTR_PARSE_PROCEED) { + /* Finally intern unknown attribute. */ + if (transit) + bgp_attr_set_transit(attr, transit_intern(transit)); +-- +2.43.0 + diff --git a/0006-CVE-2023-47234.patch b/0006-CVE-2023-47234.patch new file mode 100644 index 0000000..39f1886 --- /dev/null +++ b/0006-CVE-2023-47234.patch @@ -0,0 +1,95 @@ +From 7fe95b24333cceb6cd04595694cd502fcd3666f6 Mon Sep 17 00:00:00 2001 +From: rpm-build +Date: Wed, 13 Dec 2023 18:25:48 +0100 +Subject: [PATCH] bgpd: Ignore handling NLRIs if we received MP_UNREACH_NLRI + +If we receive MP_UNREACH_NLRI, we should stop handling remaining NLRIs if +no mandatory path attributes received. + +In other words, if MP_UNREACH_NLRI received, the remaining NLRIs should be handled +as a new data, but without mandatory attributes, it's a malformed packet. + +In normal case, this MUST not happen at all, but to avoid crashing bgpd, we MUST +handle that. + +Reported-by: Iggy Frankovic +Signed-off-by: Donatas Abraitis +Signed-off-by: Christian Breunig + +(cherry picked from commit c37119df45bbf4ef713bc10475af2ee06e12f3bf) +--- + bgpd/bgp_attr.c | 19 ++++++++++--------- + bgpd/bgp_attr.h | 1 + + bgpd/bgp_packet.c | 7 ++++++- + 3 files changed, 17 insertions(+), 10 deletions(-) + +diff --git a/bgpd/bgp_attr.c b/bgpd/bgp_attr.c +index 12a6953..8b02f2c 100644 +--- a/bgpd/bgp_attr.c ++++ b/bgpd/bgp_attr.c +@@ -3086,15 +3086,6 @@ static int bgp_attr_check(struct peer *peer, struct attr *attr) + if (CHECK_FLAG(peer->cap, PEER_CAP_RESTART_RCV) && !attr->flag) + return BGP_ATTR_PARSE_WITHDRAW; + +- /* "An UPDATE message that contains the MP_UNREACH_NLRI is not required +- to carry any other path attributes.", though if MP_REACH_NLRI or NLRI +- are present, it should. Check for any other attribute being present +- instead. +- */ +- if ((!CHECK_FLAG(attr->flag, ATTR_FLAG_BIT(BGP_ATTR_MP_REACH_NLRI)) && +- CHECK_FLAG(attr->flag, ATTR_FLAG_BIT(BGP_ATTR_MP_UNREACH_NLRI)))) +- return BGP_ATTR_PARSE_PROCEED; +- + if (!CHECK_FLAG(attr->flag, ATTR_FLAG_BIT(BGP_ATTR_ORIGIN))) + type = BGP_ATTR_ORIGIN; + +@@ -3113,6 +3104,16 @@ static int bgp_attr_check(struct peer *peer, struct attr *attr) + && !CHECK_FLAG(attr->flag, ATTR_FLAG_BIT(BGP_ATTR_LOCAL_PREF))) + type = BGP_ATTR_LOCAL_PREF; + ++ /* An UPDATE message that contains the MP_UNREACH_NLRI is not required ++ * to carry any other path attributes. Though if MP_REACH_NLRI or NLRI ++ * are present, it should. Check for any other attribute being present ++ * instead. ++ */ ++ if (!CHECK_FLAG(attr->flag, ATTR_FLAG_BIT(BGP_ATTR_MP_REACH_NLRI)) && ++ CHECK_FLAG(attr->flag, ATTR_FLAG_BIT(BGP_ATTR_MP_UNREACH_NLRI))) ++ return type ? BGP_ATTR_PARSE_MISSING_MANDATORY ++ : BGP_ATTR_PARSE_PROCEED; ++ + /* If any of the well-known mandatory attributes are not present + * in an UPDATE message, then "treat-as-withdraw" MUST be used. + */ +diff --git a/bgpd/bgp_attr.h b/bgpd/bgp_attr.h +index 06f350b..b9dfec9 100644 +--- a/bgpd/bgp_attr.h ++++ b/bgpd/bgp_attr.h +@@ -379,6 +379,7 @@ enum bgp_attr_parse_ret { + */ + BGP_ATTR_PARSE_ERROR_NOTIFYPLS = -3, + BGP_ATTR_PARSE_EOR = -4, ++ BGP_ATTR_PARSE_MISSING_MANDATORY = -5, + }; + + struct bpacket_attr_vec_arr; +diff --git a/bgpd/bgp_packet.c b/bgpd/bgp_packet.c +index a5f065a..cdf0734 100644 +--- a/bgpd/bgp_packet.c ++++ b/bgpd/bgp_packet.c +@@ -1873,7 +1873,12 @@ static int bgp_update_receive(struct peer *peer, bgp_size_t size) + /* Network Layer Reachability Information. */ + update_len = end - stream_pnt(s); + +- if (update_len && attribute_len) { ++ /* If we received MP_UNREACH_NLRI attribute, but also NLRIs, then ++ * NLRIs should be handled as a new data. Though, if we received ++ * NLRIs without mandatory attributes, they should be ignored. ++ */ ++ if (update_len && attribute_len && ++ attr_parse_ret != BGP_ATTR_PARSE_MISSING_MANDATORY) { + /* Set NLRI portion to structure. */ + nlris[NLRI_UPDATE].afi = AFI_IP; + nlris[NLRI_UPDATE].safi = SAFI_UNICAST; +-- +2.43.0 + diff --git a/frr.spec b/frr.spec index 0f721fa..1ddb3d0 100644 --- a/frr.spec +++ b/frr.spec @@ -7,7 +7,7 @@ Name: frr Version: 8.5.3 -Release: 1%{?checkout}%{?dist} +Release: 2%{?checkout}%{?dist} Summary: Routing daemon License: GPLv2+ URL: http://www.frrouting.org @@ -67,6 +67,8 @@ Patch0000: 0000-remove-babeld-and-ldpd.patch Patch0002: 0002-enable-openssl.patch Patch0003: 0003-disable-eigrp-crypto.patch Patch0004: 0004-fips-mode.patch +Patch0005: 0005-CVE-2023-47235.patch +Patch0006: 0006-CVE-2023-47234.patch %description FRRouting is free software that manages TCP/IP based routing protocols. It takes @@ -272,6 +274,10 @@ make check PYTHON=%{__python3} %endif %changelog +* Mon Dec 18 2023 Michal Ruprich - 8.5.3-2 +- Resolves: RHEL-15915 - crash from specially crafted MP_UNREACH_NLRI-containing BGP UPDATE message +- Resolves: RHEL-15918 - crash from malformed EOR-containing BGP UPDATE message + * Thu Nov 23 2023 Michal Ruprich - 8.5.3-1 - Resolves: RHEL-15291 - Rebase FRR to version 8.5.3 in RHEL9