diff options
Diffstat (limited to '0006-CVE-2023-47234.patch')
| -rw-r--r-- | 0006-CVE-2023-47234.patch | 95 |
1 files changed, 95 insertions, 0 deletions
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 <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 <iggyfran@amazon.com> +Signed-off-by: Donatas Abraitis <donatas@opensourcerouting.org> +Signed-off-by: Christian Breunig <christian@breunig.cc> + +(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 + |