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>
This commit is contained in:
Zhang Peng
2024-11-26 16:11:14 +08:00
committed by Armin Kuster
parent 327470f000
commit 483946a97b
2 changed files with 111 additions and 0 deletions

View File

@@ -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

View File

@@ -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"