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From: Sven Eckelmann <sven@narfation.org>
To: b.a.t.m.a.n@lists.open-mesh.org
Cc: Sven Eckelmann <sven@narfation.org>,
	Marco Dalla Torre <marco.dallato@gmail.com>
Subject: [PATCH 4/6] batctl: tcpdump: Add missing ICMPv6 Neighbor Advert length check
Date: Sat, 27 Jan 2024 13:49:02 +0100	[thread overview]
Message-ID: <20240127-tcpdump_fuzzing-v1-4-fbc1e1d3fec1@narfation.org> (raw)
In-Reply-To: <20240127-tcpdump_fuzzing-v1-0-fbc1e1d3fec1@narfation.org>

dump_ipv6() is doing a length check for the original ICMPv6 header length.
But the neighbor advertisement (which is also handled by this function) is
accessed without doing an additional length check. So it is possible that
it tries to read outside of the received data.

Fixes: 35b37756f4a3 ("add IPv6 support to tcpdump parser")
Cc: Marco Dalla Torre <marco.dallato@gmail.com>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
---
 tcpdump.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/tcpdump.c b/tcpdump.c
index 3fdd7c3..2ae3909 100644
--- a/tcpdump.c
+++ b/tcpdump.c
@@ -659,6 +659,8 @@ static void dump_ipv6(unsigned char *packet_buff, ssize_t buff_len,
 			       nd_nas_target, buff_len);
 			break;
 		case ND_NEIGHBOR_ADVERT:
+			LEN_CHECK((size_t)buff_len - (size_t)(sizeof(struct ip6_hdr)),
+				  sizeof(*nd_advert), "ICMPv6 Neighbor Advertisement");
 			nd_advert = (struct nd_neighbor_advert *)icmphdr;
 			inet_ntop(AF_INET6, &(nd_advert->nd_na_target),
 				  nd_nas_target, 40);

-- 
2.39.2


  parent reply	other threads:[~2024-01-27 12:52 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-01-27 12:48 [PATCH 0/6] batctl: tcpdump: Fix problems detected during fuzzing Sven Eckelmann
2024-01-27 12:48 ` [PATCH 1/6] batctl: tcpdump: Fix missing sanity check for batman-adv header Sven Eckelmann
2024-01-27 12:49 ` [PATCH 2/6] batctl: tcpdump: Add missing throughput header length check Sven Eckelmann
2024-01-27 12:49 ` [PATCH 3/6] batctl: tcpdump: Fix IPv4 " Sven Eckelmann
2024-01-27 12:49 ` Sven Eckelmann [this message]
2024-01-27 12:49 ` [PATCH 5/6] batctl: tcpdump: Add missing ICMPv6 Neighbor Solicit " Sven Eckelmann
2024-01-27 12:49 ` [PATCH 6/6] batctl: tcpdump: Fix ICMPv4 inner IPv4 header " Sven Eckelmann
2024-01-27 12:51 ` [PATCH 0/6] batctl: tcpdump: Fix problems detected during fuzzing Sven Eckelmann

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