Re: [PATCH 0/3] Ioctl buffer name/path validation

[Boris Burkov <boris@bur.io>]

On Wed, Feb 14, 2024 at 07:31:54PM +0100, David Sterba wrote:
> This is inspired by a report and fix [1] where device replace buffers
> were not properly validated (third patch). The other two are doing
> proper validation of vol args path or name so that an unterminated
> string is reported as an error rather than relying on later actions like
> open that would catch an invalid path.
> 
> (I'm OK to replace the third patch in favor of Edward as he spent time
> analyzing it but we did not agree on a fix and I did not get a reply
> with the suggestion I implemented in the end.)
> 
> [1] https://lore.kernel.org/linux-btrfs/tencent_44CA0665C9836EF9EEC80CB9E7E206DF5206@qq.com/

LGTM. One note/question: would it be helpful to pull out:

```
if (memchr(str, 0, str) == NULL)
        return -ENAMETOOLONG;
return 0;
```

into a helper and use it in all these places?

Either way,
Reviewed-by: Boris Burkov <boris@bur.io>

> 
> David Sterba (3):
>   btrfs: factor out validation of btrfs_ioctl_vol_args::name
>   btrfs: factor out validation of btrfs_ioctl_vol_args_v2::name
>   btrfs: dev-replace: properly validate device names
> 
>  fs/btrfs/dev-replace.c | 24 +++++++++++++++----
>  fs/btrfs/fs.h          |  2 ++
>  fs/btrfs/ioctl.c       | 54 +++++++++++++++++++++++++++++++++++-------
>  fs/btrfs/super.c       |  5 +++-
>  4 files changed, 72 insertions(+), 13 deletions(-)
> 
> -- 
> 2.42.1
>