From a23a2b5128fe28455ab8b043c906bcbd2beae094 Mon Sep 17 00:00:00 2001 From: Dan Carpenter Date: Wed, 3 Apr 2019 08:34:16 +0300 Subject: [PATCH] 6lowpan: Off by one handling ->nexthdr [ Upstream commit f57c4bbf34439531adccd7d3a4ecc14f409c1399 ] 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 Acked-by: Jukka Rissanen Acked-by: Alexander Aring Signed-off-by: Marcel Holtmann Signed-off-by: Sasha Levin --- net/6lowpan/nhc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/6lowpan/nhc.c b/net/6lowpan/nhc.c index 4fa2fdd..9e56fb9 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) -- 2.7.4