frr: fix CVE-2024-31951

CVE-2024-31951:
In the Opaque LSA Extended Link parser in FRRouting (FRR) through 9.1, there can be a
buffer overflow and daemon crash in ospf_te_parse_ext_link for OSPF LSA packets during
an attempt to read Segment Routing Adjacency SID subTLVs (lengths are not validated).

Reference:
[https://nvd.nist.gov/vuln/detail/CVE-2024-31951]

Upstream patches:
[5557a289ac]

Signed-off-by: Zhang Peng <peng.zhang1.cn@windriver.com>
Signed-off-by: Armin Kuster <akuster808@gmail.com>

meta-networking/recipes-protocols/frr/frr/CVE-2024-31951.patch

@@ -0,0 +1,110 @@
+From 5557a289acdaeec8cc63ffc97b5c2abf6dee7b3a Mon Sep 17 00:00:00 2001
+From: Olivier Dugeon <olivier.dugeon@orange.com>
+Date: Fri, 5 Apr 2024 12:57:11 +0200
+Subject: [PATCH] ospfd: Correct Opaque LSA Extended parser
+
+Iggy Frankovic discovered another ospfd crash when performing fuzzing of OSPF
+LSA packets. The crash occurs in ospf_te_parse_ext_link() function when
+attemping to read Segment Routing Adjacency SID subTLVs. The original code
+doesn't check if the size of the Extended Link TLVs and subTLVs have the correct
+length. In presence of erronous LSA, this will cause a buffer overflow and ospfd
+crashes.
+
+This patch introduces new verification of the subTLVs size for Extended Link
+TLVs and subTLVs. Similar check has been also introduced for the Extended
+Prefix TLV.
+
+Co-authored-by: Iggy Frankovic <iggyfran@amazon.com>
+Signed-off-by: Olivier Dugeon <olivier.dugeon@orange.com>
+
+CVE: CVE-2024-31951
+Upstream-Status: Backport [https://github.com/FRRouting/frr/commit/5557a289acdaeec8cc63ffc97b5c2abf6dee7b3a]
+
+Signed-off-by: Zhang Peng <peng.zhang1.cn@windriver.com>
+---
+ ospfd/ospf_te.c | 35 +++++++++++++++++++++++++++++++++--
+ 1 file changed, 33 insertions(+), 2 deletions(-)
+
+diff --git a/ospfd/ospf_te.c b/ospfd/ospf_te.c
+index 091669d8ed36..e68f9444f512 100644
+--- a/ospfd/ospf_te.c
++++ b/ospfd/ospf_te.c
+@@ -2620,6 +2620,7 @@ static int ospf_te_parse_ext_pref(struct ls_ted *ted, struct ospf_lsa *lsa)
+ 	struct ext_tlv_prefix *ext;
+ 	struct ext_subtlv_prefix_sid *pref_sid;
+ 	uint32_t label;
++	uint16_t len, size;
+ 
+ 	/* Get corresponding Subnet from Link State Data Base */
+ 	ext = (struct ext_tlv_prefix *)TLV_HDR_TOP(lsa->data);
+@@ -2641,6 +2642,18 @@ static int ospf_te_parse_ext_pref(struct ls_ted *ted, struct ospf_lsa *lsa)
+ 	ote_debug("  |- Process Extended Prefix LSA %pI4 for subnet %pFX",
+ 		  &lsa->data->id, &pref);
+ 
++	/*
++	 * Check Extended Prefix TLV size against LSA size
++	 * as only one TLV is allowed per LSA
++	 */
++	len = TLV_BODY_SIZE(&ext->header);
++	size = lsa->size - (OSPF_LSA_HEADER_SIZE + TLV_HDR_SIZE);
++	if (len != size || len <= 0) {
++		ote_debug("  |- Wrong TLV size: %u instead of %u",
++			  (uint32_t)len, (uint32_t)size);
++		return -1;
++	}
++
+ 	/* Initialize TLV browsing */
+ 	ls_pref = subnet->ls_pref;
+ 	pref_sid = (struct ext_subtlv_prefix_sid *)((char *)(ext) + TLV_HDR_SIZE
+@@ -2751,8 +2764,20 @@ static int ospf_te_parse_ext_link(struct ls_ted *ted, struct ospf_lsa *lsa)
+ 	ote_debug("  |- Process Extended Link LSA %pI4 for edge %pI4",
+ 		  &lsa->data->id, &edge->attributes->standard.local);
+ 
+-	/* Initialize TLV browsing */
+-	len = TLV_BODY_SIZE(&ext->header) - EXT_TLV_LINK_SIZE;
++	/*
++	 * Check Extended Link TLV size against LSA size
++	 * as only one TLV is allowed per LSA
++	 */
++	len = TLV_BODY_SIZE(&ext->header);
++	i = lsa->size - (OSPF_LSA_HEADER_SIZE + TLV_HDR_SIZE);
++	if (len != i || len <= 0) {
++		ote_debug("  |- Wrong TLV size: %u instead of %u",
++			  (uint32_t)len, (uint32_t)i);
++		return -1;
++	}
++
++	/* Initialize subTLVs browsing */
++	len -= EXT_TLV_LINK_SIZE;
+ 	tlvh = (struct tlv_header *)((char *)(ext) + TLV_HDR_SIZE
+ 				     + EXT_TLV_LINK_SIZE);
+ 	for (; sum < len; tlvh = TLV_HDR_NEXT(tlvh)) {
+@@ -2762,6 +2787,8 @@ static int ospf_te_parse_ext_link(struct ls_ted *ted, struct ospf_lsa *lsa)
+ 
+ 		switch (ntohs(tlvh->type)) {
+ 		case EXT_SUBTLV_ADJ_SID:
++			if (TLV_BODY_SIZE(tlvh) != EXT_SUBTLV_ADJ_SID_SIZE)
++				break;
+ 			adj = (struct ext_subtlv_adj_sid *)tlvh;
+ 			label = CHECK_FLAG(adj->flags,
+ 					   EXT_SUBTLV_LINK_ADJ_SID_VFLG)
+@@ -2788,6 +2815,8 @@ static int ospf_te_parse_ext_link(struct ls_ted *ted, struct ospf_lsa *lsa)
+ 
+ 			break;
+ 		case EXT_SUBTLV_LAN_ADJ_SID:
++			if (TLV_BODY_SIZE(tlvh) != EXT_SUBTLV_LAN_ADJ_SID_SIZE)
++				break;
+ 			ladj = (struct ext_subtlv_lan_adj_sid *)tlvh;
+ 			label = CHECK_FLAG(ladj->flags,
+ 					   EXT_SUBTLV_LINK_ADJ_SID_VFLG)
+@@ -2817,6 +2846,8 @@ static int ospf_te_parse_ext_link(struct ls_ted *ted, struct ospf_lsa *lsa)
+ 
+ 			break;
+ 		case EXT_SUBTLV_RMT_ITF_ADDR:
++			if (TLV_BODY_SIZE(tlvh) != EXT_SUBTLV_RMT_ITF_ADDR_SIZE)
++				break;
+ 			rmt = (struct ext_subtlv_rmt_itf_addr *)tlvh;
+ 			if (CHECK_FLAG(atr->flags, LS_ATTR_NEIGH_ADDR)
+ 			    && IPV4_ADDR_SAME(&atr->standard.remote,
+--
+2.34.1

meta-networking/recipes-protocols/frr/frr_9.1.bb

@@ -15,6 +15,7 @@ SRC_URI = "git://github.com/FRRouting/frr.git;protocol=https;branch=stable/9.1 \
            file://0001-zebra-Mimic-GNU-basename-API-for-non-glibc-library-e.patch \
            file://CVE-2024-34088.patch \
            file://CVE-2024-31950.patch \
+           file://CVE-2024-31951.patch \
            "
 
 SRCREV = "ca2d6f0f1e000951224a18973cc1827f7f5215b5"