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frr/SOURCES/0009-CVE-2022-36440-40302.p...

60 lines
1.9 KiB

From 3e46b43e3788f0f87bae56a86b54d412b4710286 Mon Sep 17 00:00:00 2001
From: Donald Sharp <sharpd@nvidia.com>
Date: Fri, 30 Sep 2022 08:51:45 -0400
Subject: [PATCH] bgpd: Ensure FRR has enough data to read 2 bytes in
peek_for_as4_capability
In peek_for_as4_capability the code is checking that the
stream has at least 2 bytes to read ( the opt_type and the
opt_length ). However if BGP_OPEN_EXT_OPT_PARAMS_CAPABLE(peer)
is configured then FRR is reading 3 bytes. Which is not good
since the packet could be badly formated. Ensure that
FRR has the appropriate data length to read the data.
Signed-off-by: Donald Sharp <sharpd@nvidia.com>
---
bgpd/bgp_open.c | 27 +++++++++++++++++++++------
1 file changed, 21 insertions(+), 6 deletions(-)
diff --git a/bgpd/bgp_open.c b/bgpd/bgp_open.c
index 7248f034a5a..a760a7ca013 100644
--- a/bgpd/bgp_open.c
+++ b/bgpd/bgp_open.c
@@ -1185,15 +1185,30 @@ as_t peek_for_as4_capability(struct peer *peer, uint16_t length)
uint8_t opt_type;
uint16_t opt_length;
- /* Check the length. */
- if (stream_get_getp(s) + 2 > end)
+ /* Ensure we can read the option type */
+ if (stream_get_getp(s) + 1 > end)
goto end;
- /* Fetch option type and length. */
+ /* Fetch the option type */
opt_type = stream_getc(s);
- opt_length = BGP_OPEN_EXT_OPT_PARAMS_CAPABLE(peer)
- ? stream_getw(s)
- : stream_getc(s);
+
+ /*
+ * Check the length and fetch the opt_length
+ * If the peer is BGP_OPEN_EXT_OPT_PARAMS_CAPABLE(peer)
+ * then we do a getw which is 2 bytes. So we need to
+ * ensure that we can read that as well
+ */
+ if (BGP_OPEN_EXT_OPT_PARAMS_CAPABLE(peer)) {
+ if (stream_get_getp(s) + 2 > end)
+ goto end;
+
+ opt_length = stream_getw(s);
+ } else {
+ if (stream_get_getp(s) + 1 > end)
+ goto end;
+
+ opt_length = stream_getc(s);
+ }
/* Option length check. */
if (stream_get_getp(s) + opt_length > end)