File 0020-bgpd-Fix-use-beyond-end-of-stream-of-label... of Package frr

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File 0020-bgpd-Fix-use-beyond-end-of-stream-of-labeled-unicast.patch of Package frr

From 995d2dc58dec7196d2cae7cf0fa767f9e0c46c91 Mon Sep 17 00:00:00 2001
From: Donald Sharp <sharpd@nvidia.com>
Date: Fri, 3 Mar 2023 21:58:33 -0500
Subject: [PATCH] bgpd: Fix use beyond end of stream of labeled unicast
 parsing
Upstream: yes
References: CVE-2023-38407,bsc#1216899,https://github.com/FRRouting/frr/pull/12956/commits/ab362eae68edec12c175d9bc488bcc3f8b73d36f

Fixes a couple crashes associated with attempting to read
beyond the end of the stream.

Reported-by: Iggy Frankovic <iggyfran@amazon.com>
Signed-off-by: Donald Sharp <sharpd@nvidia.com>
(cherry picked from commit 7404a914b0cafe046703c8381903a80d3def8f8b)

diff --git a/bgpd/bgp_label.c b/bgpd/bgp_label.c
index ec44037bf7..488b0954c7 100644
--- a/bgpd/bgp_label.c
+++ b/bgpd/bgp_label.c
@@ -304,6 +304,9 @@ static int bgp_nlri_get_labels(struct peer *peer, uint8_t *pnt, uint8_t plen,
 	uint8_t llen = 0;
 	uint8_t label_depth = 0;
 
+	if (plen < BGP_LABEL_BYTES)
+		return 0;
+
 	for (; data < lim; data += BGP_LABEL_BYTES) {
 		memcpy(label, data, BGP_LABEL_BYTES);
 		llen += BGP_LABEL_BYTES;
@@ -369,6 +372,9 @@ int bgp_nlri_parse_label(struct peer *peer, struct attr *attr,
 			memcpy(&addpath_id, pnt, BGP_ADDPATH_ID_LEN);
 			addpath_id = ntohl(addpath_id);
 			pnt += BGP_ADDPATH_ID_LEN;
+
+			if (pnt >= lim)
+				return BGP_NLRI_PARSE_ERROR_PACKET_OVERFLOW;
 		}
 
 		/* Fetch prefix length. */
@@ -387,6 +393,15 @@ int bgp_nlri_parse_label(struct peer *peer, struct attr *attr,
 
 		/* Fill in the labels */
 		llen = bgp_nlri_get_labels(peer, pnt, psize, &label);
+		if (llen == 0) {
+			flog_err(
+				EC_BGP_UPDATE_RCV,
+				"%s [Error] Update packet error (wrong label length 0)",
+				peer->host);
+			bgp_notify_send(peer, BGP_NOTIFY_UPDATE_ERR,
+					BGP_NOTIFY_UPDATE_INVAL_NETWORK);
+			return BGP_NLRI_PARSE_ERROR_LABEL_LENGTH;
+		}
 		p.prefixlen = prefixlen - BSIZE(llen);
 
 		/* There needs to be at least one label */
-- 
2.35.3

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File 0020-bgpd-Fix-use-beyond-end-of-stream-of-labeled-unicast.patch of Package frr

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