bail-out-from-make_indexed_dir-on-first-error

   1 ext4: bail out from make_indexed_dir() on first error
   2
   3 From: Jan Kara <jack@suse.cz>
   4
   5 When ext4_handle_dirty_dx_node() or ext4_handle_dirty_dirent_node()
   6 fail, there's really something wrong with the fs and there's no point in
   7 continuing further. Just return error from make_indexed_dir() in that
   8 case. Also initialize frames array so that if we return early due to
   9 error, dx_release() doesn't try to dereference uninitialized memory
  10 (which could happen also due to error in do_split()).
  11
  12 Coverity-id: 741300
  13 Signed-off-by: Jan Kara <jack@suse.cz>
  14 Signed-off-by: Theodore Ts'o <tytso@mit.edu>
  15 Cc: stable@vger.kernel.org
  16 ---
  17  fs/ext4/namei.c | 28 ++++++++++++++++++----------
  18  1 file changed, 18 insertions(+), 10 deletions(-)
  19
  20 diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
  21 index adb559de23c1..cec7257aa74a 100644
  22 --- a/fs/ext4/namei.c
  23 +++ b/fs/ext4/namei.c
  24 @@ -1816,31 +1816,39 @@ static int make_indexed_dir(handle_t *handle, struct dentry *dentry,
  25                 hinfo.hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
  26         hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
  27         ext4fs_dirhash(name, namelen, &hinfo);
  28 +       memset(frames, 0, sizeof(frames));
  29         frame = frames;
  30         frame->entries = entries;
  31         frame->at = entries;
  32         frame->bh = bh;
  33         bh = bh2;
  34
  35 -       ext4_handle_dirty_dx_node(handle, dir, frame->bh);
  36 -       ext4_handle_dirty_dirent_node(handle, dir, bh);
  37 +       retval = ext4_handle_dirty_dx_node(handle, dir, frame->bh);
  38 +       if (retval)
  39 +               goto out_frames;
  40 +       retval = ext4_handle_dirty_dirent_node(handle, dir, bh);
  41 +       if (retval)
  42 +               goto out_frames;
  43
  44         de = do_split(handle,dir, &bh, frame, &hinfo);
  45         if (IS_ERR(de)) {
  46 -               /*
  47 -                * Even if the block split failed, we have to properly write
  48 -                * out all the changes we did so far. Otherwise we can end up
  49 -                * with corrupted filesystem.
  50 -                */
  51 -               ext4_mark_inode_dirty(handle, dir);
  52 -               dx_release(frames);
  53 -               return PTR_ERR(de);
  54 +               retval = PTR_ERR(de);
  55 +               goto out_frames;
  56         }
  57         dx_release(frames);
  58
  59         retval = add_dirent_to_buf(handle, dentry, inode, de, bh);
  60         brelse(bh);
  61         return retval;
  62 +out_frames:
  63 +       /*
  64 +        * Even if the block split failed, we have to properly write
  65 +        * out all the changes we did so far. Otherwise we can end up
  66 +        * with corrupted filesystem.
  67 +        */
  68 +       ext4_mark_inode_dirty(handle, dir);
  69 +       dx_release(frames);
  70 +       return retval;
  71  }
  72
  73  /*
  74 --
  75 1.8.1.4
  76
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