diff options
| author | Theodore Ts'o <tytso@mit.edu> | 2013-03-11 23:39:59 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-04-05 10:04:37 -0700 |
| commit | 2457a4005a53bd8d9a266ab8f9f6388b57ca133a (patch) | |
| tree | 02f579c0eca7f90e7c5dd0ca1d494676a1f8fb1f /fs/ext4/ialloc.c | |
| parent | 46c14b9d861886d7abb66088ffeafa9301a34397 (diff) | |
ext4: use atomic64_t for the per-flexbg free_clusters count
commit 90ba983f6889e65a3b506b30dc606aa9d1d46cd2 upstream.
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>
Signed-off-by: Lingzhu Xiang <lxiang@redhat.com>
Reviewed-by: CAI Qian <caiqian@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'fs/ext4/ialloc.c')
| -rw-r--r-- | fs/ext4/ialloc.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/fs/ext4/ialloc.c b/fs/ext4/ialloc.c index 902544e7ee5c..e42b4687dbf0 100644 --- a/fs/ext4/ialloc.c +++ b/fs/ext4/ialloc.c @@ -305,8 +305,8 @@ error_return: } struct orlov_stats { + __u64 free_clusters; __u32 free_inodes; - __u32 free_clusters; __u32 used_dirs; }; @@ -323,7 +323,7 @@ static void get_orlov_stats(struct super_block *sb, ext4_group_t g, if (flex_size > 1) { stats->free_inodes = atomic_read(&flex_group[g].free_inodes); - stats->free_clusters = atomic_read(&flex_group[g].free_clusters); + stats->free_clusters = atomic64_read(&flex_group[g].free_clusters); stats->used_dirs = atomic_read(&flex_group[g].used_dirs); return; } |