Re: [PATCH v2] nilfs2: Add pointer check for nilfs_direct_propagate()

[Ryusuke Konishi <konishi.ryusuke@gmail.com>]

On Sat, Apr 5, 2025 at 6:57 PM Wentao Liang wrote:
>
> In nilfs_direct_propagate(), the printer get from nilfs_direct_get_ptr()
> need to be checked to ensure it is not an invalid pointer.
>
> If the pointer value obtained by nilfs_direct_get_ptr() is
> NILFS_BMAP_INVALID_PTR, means that the metadata (in this case,
> i_bmap in the nilfs_inode_info struct) thatshould  point to the data
> block at the buffer head of the argument is corrupted and the data
> block is orphaned, meaning that the file system has lost consistency.
>
> Add a value check and return -EINVAL when it is an invalid pointer.
>
> Fixes: 36a580eb489f ("nilfs2: direct block mapping")
> Signed-off-by: Wentao Liang <vulab@iscas.ac.cn>
> ---
>  fs/nilfs2/direct.c | 3 +++
>  1 file changed, 3 insertions(+)
>
> diff --git a/fs/nilfs2/direct.c b/fs/nilfs2/direct.c
> index 893ab36824cc..2d8dc6b35b54 100644
> --- a/fs/nilfs2/direct.c
> +++ b/fs/nilfs2/direct.c
> @@ -273,6 +273,9 @@ static int nilfs_direct_propagate(struct nilfs_bmap *bmap,
>         dat = nilfs_bmap_get_dat(bmap);
>         key = nilfs_bmap_data_get_key(bmap, bh);
>         ptr = nilfs_direct_get_ptr(bmap, key);
> +       if (ptr == NILFS_BMAP_INVALID_PTR)
> +               return -EINVAL;
> +
>         if (!buffer_nilfs_volatile(bh)) {
>                 oldreq.pr_entry_nr = ptr;
>                 newreq.pr_entry_nr = ptr;
> --
> 2.42.0.windows.2
>

Thanks for your help!

I'll handle this patch.

Ryusuke Konishi