From 7404a914b0cafe046703c8381903a80d3def8f8b Mon Sep 17 00:00:00 2001 From: Donald Sharp Date: Fri, 3 Mar 2023 21:58:33 -0500 Subject: [PATCH] bgpd: Fix use beyond end of stream of labeled unicast parsing Fixes a couple crashes associated with attempting to read beyond the end of the stream. Reported-by: Iggy Frankovic Signed-off-by: Donald Sharp --- bgpd/bgp_label.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+) diff --git a/bgpd/bgp_label.c b/bgpd/bgp_label.c index 0cad119af101..c4a5277553ba 100644 --- a/bgpd/bgp_label.c +++ b/bgpd/bgp_label.c @@ -297,6 +297,9 @@ 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; @@ -359,6 +362,9 @@ 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. */ @@ -377,6 +383,15 @@ 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 */