Resolves: RHEL-3541 - Incorrect handling of a error in parsing of an invalid section of a BGP update can de-peer a router

This commit is contained in:
Michal Ruprich 2023-10-13 09:11:25 +02:00
parent e980c00e10
commit 0b762a19a7
2 changed files with 134 additions and 1 deletions

129
0014-CVE-2023-38802.patch Normal file
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@ -0,0 +1,129 @@
From 46817adab03802355c3cce7b753c7a735bdcc5ae Mon Sep 17 00:00:00 2001
From: Donatas Abraitis <donatas@opensourcerouting.org>
Date: Thu, 13 Jul 2023 22:32:03 +0300
Subject: [PATCH] bgpd: Use treat-as-withdraw for tunnel encapsulation
attribute
Before this path we used session reset method, which is discouraged by rfc7606.
Handle this as rfc requires.
Signed-off-by: Donatas Abraitis <donatas@opensourcerouting.org>
(cherry picked from commit bcb6b58d9530173df41d3a3cbc4c600ee0b4b186)
---
bgpd/bgp_attr.c | 61 ++++++++++++++++++++-----------------------------
1 file changed, 25 insertions(+), 36 deletions(-)
diff --git a/bgpd/bgp_attr.c b/bgpd/bgp_attr.c
index 058fae23cbd..1c0803cfd8e 100644
--- a/bgpd/bgp_attr.c
+++ b/bgpd/bgp_attr.c
@@ -1301,6 +1301,7 @@ bgp_attr_malformed(struct bgp_attr_parser_args *args, uint8_t subcode,
case BGP_ATTR_LARGE_COMMUNITIES:
case BGP_ATTR_ORIGINATOR_ID:
case BGP_ATTR_CLUSTER_LIST:
+ case BGP_ATTR_ENCAP:
return BGP_ATTR_PARSE_WITHDRAW;
case BGP_ATTR_MP_REACH_NLRI:
case BGP_ATTR_MP_UNREACH_NLRI:
@@ -2434,26 +2435,21 @@ bgp_attr_ipv6_ext_communities(struct bgp_attr_parser_args *args)
}
/* Parse Tunnel Encap attribute in an UPDATE */
-static int bgp_attr_encap(uint8_t type, struct peer *peer, /* IN */
- bgp_size_t length, /* IN: attr's length field */
- struct attr *attr, /* IN: caller already allocated */
- uint8_t flag, /* IN: attr's flags field */
- uint8_t *startp)
+static int bgp_attr_encap(struct bgp_attr_parser_args *args)
{
- bgp_size_t total;
uint16_t tunneltype = 0;
-
- total = length + (CHECK_FLAG(flag, BGP_ATTR_FLAG_EXTLEN) ? 4 : 3);
+ struct peer *const peer = args->peer;
+ struct attr *const attr = args->attr;
+ bgp_size_t length = args->length;
+ uint8_t type = args->type;
+ uint8_t flag = args->flags;
if (!CHECK_FLAG(flag, BGP_ATTR_FLAG_TRANS)
|| !CHECK_FLAG(flag, BGP_ATTR_FLAG_OPTIONAL)) {
- zlog_info(
- "Tunnel Encap attribute flag isn't optional and transitive %d",
- flag);
- bgp_notify_send_with_data(peer, BGP_NOTIFY_UPDATE_ERR,
- BGP_NOTIFY_UPDATE_ATTR_FLAG_ERR,
- startp, total);
- return -1;
+ zlog_err("Tunnel Encap attribute flag isn't optional and transitive %d",
+ flag);
+ return bgp_attr_malformed(args, BGP_NOTIFY_UPDATE_OPT_ATTR_ERR,
+ args->total);
}
if (BGP_ATTR_ENCAP == type) {
@@ -2461,12 +2457,11 @@ static int bgp_attr_encap(uint8_t type, struct peer *peer, /* IN */
uint16_t tlv_length;
if (length < 4) {
- zlog_info(
+ zlog_err(
"Tunnel Encap attribute not long enough to contain outer T,L");
- bgp_notify_send_with_data(
- peer, BGP_NOTIFY_UPDATE_ERR,
- BGP_NOTIFY_UPDATE_OPT_ATTR_ERR, startp, total);
- return -1;
+ return bgp_attr_malformed(args,
+ BGP_NOTIFY_UPDATE_OPT_ATTR_ERR,
+ args->total);
}
tunneltype = stream_getw(BGP_INPUT(peer));
tlv_length = stream_getw(BGP_INPUT(peer));
@@ -2496,13 +2491,11 @@ static int bgp_attr_encap(uint8_t type, struct peer *peer, /* IN */
}
if (sublength > length) {
- zlog_info(
- "Tunnel Encap attribute sub-tlv length %d exceeds remaining length %d",
- sublength, length);
- bgp_notify_send_with_data(
- peer, BGP_NOTIFY_UPDATE_ERR,
- BGP_NOTIFY_UPDATE_OPT_ATTR_ERR, startp, total);
- return -1;
+ zlog_err("Tunnel Encap attribute sub-tlv length %d exceeds remaining length %d",
+ sublength, length);
+ return bgp_attr_malformed(args,
+ BGP_NOTIFY_UPDATE_OPT_ATTR_ERR,
+ args->total);
}
/* alloc and copy sub-tlv */
@@ -2550,13 +2543,10 @@ static int bgp_attr_encap(uint8_t type, struct peer *peer, /* IN */
if (length) {
/* spurious leftover data */
- zlog_info(
- "Tunnel Encap attribute length is bad: %d leftover octets",
- length);
- bgp_notify_send_with_data(peer, BGP_NOTIFY_UPDATE_ERR,
- BGP_NOTIFY_UPDATE_OPT_ATTR_ERR,
- startp, total);
- return -1;
+ zlog_err("Tunnel Encap attribute length is bad: %d leftover octets",
+ length);
+ return bgp_attr_malformed(args, BGP_NOTIFY_UPDATE_OPT_ATTR_ERR,
+ args->total);
}
return 0;
@@ -3396,8 +3386,7 @@ enum bgp_attr_parse_ret bgp_attr_parse(struct peer *peer, struct attr *attr,
case BGP_ATTR_VNC:
#endif
case BGP_ATTR_ENCAP:
- ret = bgp_attr_encap(type, peer, length, attr, flag,
- startp);
+ ret = bgp_attr_encap(&attr_args);
break;
case BGP_ATTR_PREFIX_SID:
ret = bgp_attr_prefix_sid(&attr_args);

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@ -7,7 +7,7 @@
Name: frr Name: frr
Version: 8.3.1 Version: 8.3.1
Release: 11%{?checkout}%{?dist} Release: 12%{?checkout}%{?dist}
Summary: Routing daemon Summary: Routing daemon
License: GPLv2+ License: GPLv2+
URL: http://www.frrouting.org URL: http://www.frrouting.org
@ -76,6 +76,7 @@ Patch0010: 0010-CVE-2022-43681.patch
Patch0011: 0011-CVE-2022-40318.patch Patch0011: 0011-CVE-2022-40318.patch
Patch0012: 0012-bfd-not-working-in-vrf.patch Patch0012: 0012-bfd-not-working-in-vrf.patch
Patch0013: 0013-bgpd-maxttl-ebgp-multihop.patch Patch0013: 0013-bgpd-maxttl-ebgp-multihop.patch
Patch0014: 0014-CVE-2023-38802.patch
%description %description
FRRouting is free software that manages TCP/IP based routing protocols. It takes FRRouting is free software that manages TCP/IP based routing protocols. It takes
@ -281,6 +282,9 @@ make check PYTHON=%{__python3}
%endif %endif
%changelog %changelog
* Fri Oct 13 2023 Michal Ruprich <mruprich@redhat.com> - 8.3.1-12
- Resolves: RHEL-3541 - Incorrect handling of a error in parsing of an invalid section of a BGP update can de-peer a router
* Thu Sep 21 2023 Carlos Goncalves <cgoncalves@redhat.com> - 8.3.1-11 * Thu Sep 21 2023 Carlos Goncalves <cgoncalves@redhat.com> - 8.3.1-11
- Resolves: RHEL-2263 - bgpd: Do not explicitly print MAXTTL value for ebgp-multihop vty output - Resolves: RHEL-2263 - bgpd: Do not explicitly print MAXTTL value for ebgp-multihop vty output