From 90ba983f6889e65a3b506b30dc606aa9d1d46cd2 Mon Sep 17 00:00:00 2001 From: Theodore Ts'o Date: Mon, 11 Mar 2013 23:39:59 -0400 Subject: ext4: use atomic64_t for the per-flexbg free_clusters count A user who was using a 8TB+ file system and with a very large flexbg size (> 65536) could cause the atomic_t used in the struct flex_groups to overflow. This was detected by PaX security patchset: http://forums.grsecurity.net/viewtopic.php?f=3&t=3289&p=12551#p12551 This bug was introduced in commit 9f24e4208f7e, so it's been around since 2.6.30. :-( Fix this by using an atomic64_t for struct orlav_stats's free_clusters. Signed-off-by: "Theodore Ts'o" Reviewed-by: Lukas Czerner Cc: stable@vger.kernel.org --- fs/ext4/resize.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'fs/ext4/resize.c') diff --git a/fs/ext4/resize.c b/fs/ext4/resize.c index b2c8ee56eb98..c169477a62c9 100644 --- a/fs/ext4/resize.c +++ b/fs/ext4/resize.c @@ -1360,8 +1360,8 @@ static void ext4_update_super(struct super_block *sb, sbi->s_log_groups_per_flex) { ext4_group_t flex_group; flex_group = ext4_flex_group(sbi, group_data[0].group); - atomic_add(EXT4_NUM_B2C(sbi, free_blocks), - &sbi->s_flex_groups[flex_group].free_clusters); + atomic64_add(EXT4_NUM_B2C(sbi, free_blocks), + &sbi->s_flex_groups[flex_group].free_clusters); atomic_add(EXT4_INODES_PER_GROUP(sb) * flex_gd->count, &sbi->s_flex_groups[flex_group].free_inodes); } -- cgit