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| author | Theodore Ts'o <tytso@mit.edu> | 2013-03-12 04:39:59 +0100 |
|---|---|---|
| committer | Theodore Ts'o <tytso@mit.edu> | 2013-03-12 04:39:59 +0100 |
| commit | 90ba983f6889e65a3b506b30dc606aa9d1d46cd2 (patch) | |
| tree | 964ad0ccf415e73a7760b5bfe65506f5d825e1cf /fs/ext4/ext4.h | |
| parent | jbd2: fix use after free in jbd2_journal_dirty_metadata() (diff) | |
| download | linux-90ba983f6889e65a3b506b30dc606aa9d1d46cd2.tar.xz linux-90ba983f6889e65a3b506b30dc606aa9d1d46cd2.zip | |
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/ext4.h')
| -rw-r--r-- | fs/ext4/ext4.h | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h index 4a01ba315262..167ff564bbfa 100644 --- a/fs/ext4/ext4.h +++ b/fs/ext4/ext4.h @@ -335,9 +335,9 @@ struct ext4_group_desc */ struct flex_groups { - atomic_t free_inodes; - atomic_t free_clusters; - atomic_t used_dirs; + atomic64_t free_clusters; + atomic_t free_inodes; + atomic_t used_dirs; }; #define EXT4_BG_INODE_UNINIT 0x0001 /* Inode table/bitmap not in use */ |