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| author | Theodore Ts'o <tytso@mit.edu> | 2013-03-11 23:39:59 -0400 |
|---|---|---|
| committer | Theodore Ts'o <tytso@mit.edu> | 2013-03-11 23:39:59 -0400 |
| commit | 90ba983f6889e65a3b506b30dc606aa9d1d46cd2 (patch) | |
| tree | 964ad0ccf415e73a7760b5bfe65506f5d825e1cf /fs/ext4/mballoc.c | |
| parent | ad56edad089b56300fd13bb9eeb7d0424d978239 (diff) | |
| download | blackbird-obmc-linux-90ba983f6889e65a3b506b30dc606aa9d1d46cd2.tar.gz blackbird-obmc-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/mballoc.c')
| -rw-r--r-- | fs/ext4/mballoc.c | 12 |
1 files changed, 6 insertions, 6 deletions
diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c index 8b2ea9f75004..ee6614bdb639 100644 --- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -2804,8 +2804,8 @@ ext4_mb_mark_diskspace_used(struct ext4_allocation_context *ac, if (sbi->s_log_groups_per_flex) { ext4_group_t flex_group = ext4_flex_group(sbi, ac->ac_b_ex.fe_group); - atomic_sub(ac->ac_b_ex.fe_len, - &sbi->s_flex_groups[flex_group].free_clusters); + atomic64_sub(ac->ac_b_ex.fe_len, + &sbi->s_flex_groups[flex_group].free_clusters); } err = ext4_handle_dirty_metadata(handle, NULL, bitmap_bh); @@ -4661,8 +4661,8 @@ do_more: if (sbi->s_log_groups_per_flex) { ext4_group_t flex_group = ext4_flex_group(sbi, block_group); - atomic_add(count_clusters, - &sbi->s_flex_groups[flex_group].free_clusters); + atomic64_add(count_clusters, + &sbi->s_flex_groups[flex_group].free_clusters); } ext4_mb_unload_buddy(&e4b); @@ -4804,8 +4804,8 @@ int ext4_group_add_blocks(handle_t *handle, struct super_block *sb, if (sbi->s_log_groups_per_flex) { ext4_group_t flex_group = ext4_flex_group(sbi, block_group); - atomic_add(EXT4_NUM_B2C(sbi, blocks_freed), - &sbi->s_flex_groups[flex_group].free_clusters); + atomic64_add(EXT4_NUM_B2C(sbi, blocks_freed), + &sbi->s_flex_groups[flex_group].free_clusters); } ext4_mb_unload_buddy(&e4b); |
