[PATCH] fib_trie: potential out of bounds access in trie_show_stats()

From: Jerry Snitselaar
Date: Mon Jul 22 2013 - 15:02:33 EST


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 <jerry.snitselaar@xxxxxxxxxx>
---
net/ipv4/fib_trie.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/ipv4/fib_trie.c b/net/ipv4/fib_trie.c
index 49616fe..108a1e9c 100644
--- a/net/ipv4/fib_trie.c
+++ b/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];
--
1.8.3.2.701.g8c4e4ec

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