[PATCH 3.10 07/54] ext4: fix potential integer overflow

From: Greg Kroah-Hartman
Date: Tue Feb 23 2016 - 22:59:24 EST


3.10-stable review patch. If anyone has any objections, please let me know.

------------------

From: Insu Yun <wuninsu@xxxxxxxxx>

commit 46901760b46064964b41015d00c140c83aa05bcf upstream.

Since sizeof(ext_new_group_data) > sizeof(ext_new_flex_group_data),
integer overflow could be happened.
Therefore, need to fix integer overflow sanitization.

Signed-off-by: Insu Yun <wuninsu@xxxxxxxxx>
Signed-off-by: Theodore Ts'o <tytso@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
fs/ext4/resize.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/fs/ext4/resize.c
+++ b/fs/ext4/resize.c
@@ -181,7 +181,7 @@ static struct ext4_new_flex_group_data *
if (flex_gd == NULL)
goto out3;

- if (flexbg_size >= UINT_MAX / sizeof(struct ext4_new_flex_group_data))
+ if (flexbg_size >= UINT_MAX / sizeof(struct ext4_new_group_data))
goto out2;
flex_gd->count = flexbg_size;