3.4-stable review patch. If anyone has any objections, please let me know.
------------------ From: Haogang Chen <[email protected]> commit 967ac8af4475ce45474800709b12137aa7634c77 upstream. In alloc_flex_gd(), when flexbg_size is large, kmalloc size would overflow and flex_gd->groups would point to a buffer smaller than expected, causing OOB accesses when it is used. Note that in ext4_resize_fs(), flexbg_size is calculated using sbi->s_log_groups_per_flex, which is read from the disk and only bounded to [1, 31]. The patch returns NULL for too large flexbg_size. Reviewed-by: Eric Sandeen <[email protected]> Signed-off-by: Haogang Chen <[email protected]> Signed-off-by: "Theodore Ts'o" <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- fs/ext4/resize.c | 2 ++ 1 file changed, 2 insertions(+) --- a/fs/ext4/resize.c +++ b/fs/ext4/resize.c @@ -161,6 +161,8 @@ 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)) + goto out2; flex_gd->count = flexbg_size; flex_gd->groups = kmalloc(sizeof(struct ext4_new_group_data) * -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
