[PATCH] fs/nilfs2: prevent int overflow in btree binary search

[Sabyrzhan Tasbolatov]

Should prevent int overflow if low + high > INT_MAX in big btree with
nchildren in nilfs_btree_node_lookup() binary search.

Signed-off-by: Sabyrzhan Tasbolatov <snovitoll@xxxxxxxxx>
---
 fs/nilfs2/btree.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/nilfs2/btree.c b/fs/nilfs2/btree.c
index 65659fa03..39ee4fe11 100644
--- a/fs/nilfs2/btree.c
+++ b/fs/nilfs2/btree.c
@@ -300,7 +300,7 @@ static int nilfs_btree_node_lookup(const struct nilfs_btree_node *node,
 	index = 0;
 	s = 0;
 	while (low <= high) {
-		index = (low + high) / 2;
+		index = low + (high - low) / 2;
 		nkey = nilfs_btree_node_get_key(node, index);
 		if (nkey == key) {
 			s = 0;
-- 
2.34.1