From: Dan Carpenter <dan.carpenter@oracle.com>
To: Alexander Aring <alex.aring@gmail.com>
Cc: Jukka Rissanen <jukka.rissanen@linux.intel.com>,
"David S. Miller" <davem@davemloft.net>,
linux-bluetooth@vger.kernel.org, linux-wpan@vger.kernel.org,
netdev@vger.kernel.org, kernel-janitors@vger.kernel.org
Subject: [PATCH net] 6lowpan: Off by one handling ->nexthdr
Date: Wed, 3 Apr 2019 08:34:16 +0300 [thread overview]
Message-ID: <20190403053416.GA21913@kadam> (raw)
NEXTHDR_MAX is 255. What happens here is that we take a u8 value
"hdr->nexthdr" from the network and then look it up in
lowpan_nexthdr_nhcs[]. The problem is that if hdr->nexthdr is 0xff then
we read one element beyond the end of the array so the array needs to
be one element larger.
Fixes: 92aa7c65d295 ("6lowpan: add generic nhc layer interface")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
---
This is the only place which uses the NEXTHDR_MAX define, so I considered
changing that to 256 instead. Either fix would work.
net/6lowpan/nhc.c | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)
diff --git a/net/6lowpan/nhc.c b/net/6lowpan/nhc.c
index 4fa2fdda174d..9e56fb98f33c 100644
--- a/net/6lowpan/nhc.c
+++ b/net/6lowpan/nhc.c
@@ -18,7 +18,7 @@
#include "nhc.h"
static struct rb_root rb_root = RB_ROOT;
-static struct lowpan_nhc *lowpan_nexthdr_nhcs[NEXTHDR_MAX];
+static struct lowpan_nhc *lowpan_nexthdr_nhcs[NEXTHDR_MAX + 1];
static DEFINE_SPINLOCK(lowpan_nhc_lock);
static int lowpan_nhc_insert(struct lowpan_nhc *nhc)
--
2.17.1
next reply other threads:[~2019-04-03 5:36 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-04-03 5:34 Dan Carpenter [this message]
2019-04-03 6:23 ` [PATCH net] 6lowpan: Off by one handling ->nexthdr Jukka Rissanen
2019-04-08 18:16 ` Alexander Aring
2019-04-23 17:10 ` Marcel Holtmann
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