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authorTheodore Ts'o <tytso@mit.edu>2013-03-11 23:39:59 -0400
committerTheodore Ts'o <tytso@mit.edu>2013-03-11 23:39:59 -0400
commit90ba983f6889e65a3b506b30dc606aa9d1d46cd2 (patch)
tree964ad0ccf415e73a7760b5bfe65506f5d825e1cf /fs/ext4/super.c
parentad56edad089b56300fd13bb9eeb7d0424d978239 (diff)
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" <tytso@mit.edu> Reviewed-by: Lukas Czerner <lczerner@redhat.com> Cc: stable@vger.kernel.org
Diffstat (limited to 'fs/ext4/super.c')
-rw-r--r--fs/ext4/super.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 9379b7fbfd92..d1ee6a84338a 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -1923,8 +1923,8 @@ static int ext4_fill_flex_info(struct super_block *sb)
flex_group = ext4_flex_group(sbi, i);
atomic_add(ext4_free_inodes_count(sb, gdp),
&sbi->s_flex_groups[flex_group].free_inodes);
- atomic_add(ext4_free_group_clusters(sb, gdp),
- &sbi->s_flex_groups[flex_group].free_clusters);
+ atomic64_add(ext4_free_group_clusters(sb, gdp),
+ &sbi->s_flex_groups[flex_group].free_clusters);
atomic_add(ext4_used_dirs_count(sb, gdp),
&sbi->s_flex_groups[flex_group].used_dirs);
}