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ext4: fix a memory leak of ext4_free_data

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When freeing metadata, we will create an ext4_free_data and
insert it into the pending free list.  After the current
transaction is committed, the object will be freed.

ext4_mb_free_metadata() will check whether the area to be freed
overlaps with the pending free list. If true, return directly. At this
time, ext4_free_data is leaked.  Fortunately, the probability of this
problem is small, since it only occurs if the file system is corrupted
such that a block is claimed by more one inode and those inodes are
deleted within a single jbd2 transaction.

Signed-off-by: Chunguang Xu <brookxu@tencent.com>
Link: https://lore.kernel.org/r/1604764698-4269-8-git-send-email-brookxu@tencent.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
This commit is contained in:
Chunguang Xu 2020-11-07 23:58:18 +08:00 committed by Theodore Ts'o
parent 41fca96e63
commit cca4155372
1 changed files with 1 additions and 0 deletions
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fs/ext4/mballoc.c
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@ -5103,6 +5103,7 @@ ext4_mb_free_metadata(handle_t *handle, struct ext4_buddy *e4b,
ext4_group_first_block_no(sb, group) +
EXT4_C2B(sbi, cluster),
"Block already on to-be-freed list");
kmem_cache_free(ext4_free_data_cachep, new_entry);
return 0;
}
}