avoid-drop-reference-to-iloc.bh-twice

   1 ext4: avoid drop reference to iloc.bh twice
   2
   3 From: Pan Bian <bianpan2016@163.com>
   4
   5 The reference to iloc.bh has been dropped in ext4_mark_iloc_dirty.
   6 However, the reference is dropped again if error occurs during
   7 ext4_handle_dirty_metadata, which may result in use-after-free bugs.
   8
   9 Fixes: fb265c9cb49e("ext4: add ext4_sb_bread() to disambiguate ENOMEM cases")
  10 Signed-off-by: Pan Bian <bianpan2016@163.com>
  11 Signed-off-by: Theodore Ts'o <tytso@mit.edu>
  12 Reviewed-by: Jan Kara <jack@suse.cz>
  13 Cc: stable@kernel.org
  14 ---
  15  fs/ext4/resize.c | 1 +
  16  1 file changed, 1 insertion(+)
  17
  18 diff --git a/fs/ext4/resize.c b/fs/ext4/resize.c
  19 index e7ae26e..4d5c0fc 100644
  20 --- a/fs/ext4/resize.c
  21 +++ b/fs/ext4/resize.c
  22 @@ -874,6 +874,7 @@ static int add_new_gdb(handle_t *handle, struct inode *inode,
  23         err = ext4_handle_dirty_metadata(handle, NULL, gdb_bh);
  24         if (unlikely(err)) {
  25                 ext4_std_error(sb, err);
  26 +               iloc.bh = NULL;
  27                 goto errout;
  28         }
  29         brelse(dind);
  30 --
  31 2.7.4
  32
  33
  34