frr: Fix CVE-2023-41909

An issue was discovered in FRRouting FRR through 9.0. bgp_nlri_parse_flowspec
in bgpd/bgp_flowspec.c processes malformed requests with no attributes,
leading to a NULL pointer dereference.

References:
https://nvd.nist.gov/vuln/detail/CVE-2023-41909
https://security-tracker.debian.org/tracker/CVE-2023-41909

Signed-off-by: Narpat Mali <narpat.mali@windriver.com>
[Minor fixup ]
Signed-off-by: Armin Kuster <akuster808@gmail.com>

meta-networking/recipes-protocols/frr/frr/CVE-2023-41909.patch

@@ -0,0 +1,42 @@
+From 5966b6a1fc72d3698d08199922cc4f42ea7fc9eb Mon Sep 17 00:00:00 2001
+From: Donald Sharp <sharpd@nvidia.com>
+Date: Fri, 8 Sep 2023 11:46:12 +0000
+Subject: [PATCH] bgpd: Limit flowspec to no attribute means a implicit
+ withdrawal
+
+All other parsing functions done from bgp_nlri_parse() assume
+no attributes == an implicit withdrawal.  Let's move
+bgp_nlri_parse_flowspec() into the same alignment.
+
+Reported-by: Matteo Memelli <mmemelli@amazon.it>
+Signed-off-by: Donald Sharp <sharpd@nvidia.com>
+
+CVE: CVE-2023-41909
+
+Upstream-Status: Backport [https://github.com/FRRouting/frr/commit/cfd04dcb3e689754a72507d086ba3b9709fc5ed8]
+
+Signed-off-by: Narpat Mali <narpat.mali@windriver.com>
+---
+ bgpd/bgp_flowspec.c | 7 +++++++
+ 1 file changed, 7 insertions(+)
+
+diff --git a/bgpd/bgp_flowspec.c b/bgpd/bgp_flowspec.c
+index 341cfe9d0..3e2b1ac49 100644
+--- a/bgpd/bgp_flowspec.c
++++ b/bgpd/bgp_flowspec.c
+@@ -112,6 +112,13 @@ int bgp_nlri_parse_flowspec(struct peer *peer, struct attr *attr,
+	afi = packet->afi;
+	safi = packet->safi;
+
++	/*
++	 * All other AFI/SAFI's treat no attribute as a implicit
++	 * withdraw.  Flowspec should as well.
++	 */
++	if (!attr)
++		withdraw = 1;
++
+	if (packet->length >= FLOWSPEC_NLRI_SIZELIMIT_EXTENDED) {
+		flog_err(EC_BGP_FLOWSPEC_PACKET,
+			 "BGP flowspec nlri length maximum reached (%u)",
+--
+2.40.0

meta-networking/recipes-protocols/frr/frr_8.2.2.bb

@@ -20,6 +20,7 @@ SRC_URI = "git://github.com/FRRouting/frr.git;protocol=https;branch=stable/8.2 \
            file://CVE-2023-31490.patch \
            file://CVE-2023-38802.patch \
            file://CVE-2023-41358.patch \
+           file://CVE-2023-41909.patch \
            file://frr.pam \
 	      "