fib_trie: potential out of bounds access in trie_show_stats()

With the <= max condition in the for loop, it will be always go 1
element further than needed. If the condition for the while loop is
never met, then max is MAX_STAT_DEPTH, and for loop will walk off the
end of nodesizes[].

Signed-off-by: Jerry Snitselaar <[email protected]>
Acked-by: Hannes Frederic Sowa <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

Author: Jerry Snitselaar

net/ipv4/fib_trie.c

@@ -2133,7 +2133,7 @@ static void trie_show_stats(struct seq_file *seq, struct trie_stat *stat)
 		max--;
 
 	pointers = 0;
-	for (i = 1; i <= max; i++)
+	for (i = 1; i < max; i++)
 		if (stat->nodesizes[i] != 0) {
 			seq_printf(seq, "  %u: %u",  i, stat->nodesizes[i]);
 			pointers += (1<<i) * stat->nodesizes[i];