6lowpan: Off by one handling ->nexthdr

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: 92aa7c6 ("6lowpan: add generic nhc layer interface") Signed-off-by: Dan Carpenter <[email protected]> Acked-by: Jukka Rissanen <[email protected]> Acked-by: Alexander Aring <[email protected]> Signed-off-by: Marcel Holtmann <[email protected]>
dlitz · Apr 23, 2019 · f57c4bb · f57c4bb
1 parent 5035726
commit f57c4bb
Showing 1 changed file with 1 addition and 1 deletion.
diff --git 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)