Re: [PATCH -next 6/6] ext4: fix inode leak in 'ext4_xattr_inode_create()'

From: Jan Kara
Date: Tue Dec 06 2022 - 07:11:03 EST


On Tue 06-12-22 09:58:06, Ye Bin wrote:
> From: Ye Bin <yebin10@xxxxxxxxxx>
>
> There is issue as follows when do setxattr with inject fault:
> [localhost]#fsck.ext4 -fn /dev/sda
> e2fsck 1.46.6-rc1 (12-Sep-2022)
> Pass 1: Checking inodes, blocks, and sizes
> Pass 2: Checking directory structure
> Pass 3: Checking directory connectivity
> Pass 4: Checking reference counts
> Unattached zero-length inode 15. Clear? no
>
> Unattached inode 15
> Connect to /lost+found? no
>
> Pass 5: Checking group summary information
>
> /dev/sda: ********** WARNING: Filesystem still has errors **********
>
> /dev/sda: 15/655360 files (0.0% non-contiguous), 66755/2621440 blocks
>
> Above issue occur in 'ext4_xattr_inode_create()', if 'ext4_mark_inode_dirty()'
> failed need to drop inode's i_nlink. Or will lead to inode leak.
>
> Signed-off-by: Ye Bin <yebin10@xxxxxxxxxx>

The change looks good. Feel free to add:

Reviewed-by: Jan Kara <jack@xxxxxxx>

I'm just slightly wondering if there is ever a situation when
ext4_mark_inode_dirty() fails but the following cleanup would succeed...

Honza

> ---
> fs/ext4/xattr.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/fs/ext4/xattr.c b/fs/ext4/xattr.c
> index 003fe1f2d6a8..734f787ae7ed 100644
> --- a/fs/ext4/xattr.c
> +++ b/fs/ext4/xattr.c
> @@ -1464,6 +1464,9 @@ static struct inode *ext4_xattr_inode_create(handle_t *handle,
> if (!err)
> err = ext4_inode_attach_jinode(ea_inode);
> if (err) {
> + if (ext4_xattr_inode_dec_ref(handle, ea_inode))
> + ext4_warning_inode(ea_inode,
> + "cleanup dec ref error %d", err);
> iput(ea_inode);
> return ERR_PTR(err);
> }
> --
> 2.31.1
>
--
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR