lkml.org 
[lkml]   [2020]   [Dec]   [28]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH 4.9 155/175] ext4: fix a memory leak of ext4_free_data
    Date
    From: Chunguang Xu <brookxu@tencent.com>

    commit cca415537244f6102cbb09b5b90db6ae2c953bdd upstream.

    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
    Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

    ---
    fs/ext4/mballoc.c | 1 +
    1 file changed, 1 insertion(+)

    --- a/fs/ext4/mballoc.c
    +++ b/fs/ext4/mballoc.c
    @@ -4650,6 +4650,7 @@ ext4_mb_free_metadata(handle_t *handle,
    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;
    }
    }

    \
     
     \ /
      Last update: 2020-12-28 17:29    [W:4.050 / U:0.112 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site