Re: [PATCH v6 2/4] fs: Add missing umask strip in vfs_tmpfile

["Darrick J. Wong" <djwong@kernel.org>]

On Mon, Apr 25, 2022 at 11:09:39AM +0800, Yang Xu wrote:
> All creation paths except for O_TMPFILE handle umask in the vfs directly
> if the filesystem doesn't support or enable POSIX ACLs. If the filesystem
> does then umask handling is deferred until posix_acl_create().
> Because, O_TMPFILE misses umask handling in the vfs it will not honor
> umask settings. Fix this by adding the missing umask handling.
> 
> Fixes: 60545d0d4610 ("[O_TMPFILE] it's still short a few helpers, but infrastructure should be OK now...")

If I had a nickel for every time I felt like I was short a few
helpers... ;)

Reviewed-by: Darrick J. Wong <djwong@kernel.org>

--D

> Cc: <stable@vger.kernel.org> # 4.19+
> Reported-by: Christian Brauner (Microsoft) <brauner@kernel.org>
> Acked-by: Christian Brauner (Microsoft) <brauner@kernel.org>
> Signed-off-by: Yang Xu <xuyang2018.jy@fujitsu.com>
> ---
>  fs/namei.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/fs/namei.c b/fs/namei.c
> index 509657fdf4f5..73646e28fae0 100644
> --- a/fs/namei.c
> +++ b/fs/namei.c
> @@ -3521,6 +3521,8 @@ struct dentry *vfs_tmpfile(struct user_namespace *mnt_userns,
>  	child = d_alloc(dentry, &slash_name);
>  	if (unlikely(!child))
>  		goto out_err;
> +	if (!IS_POSIXACL(dir))
> +		mode &= ~current_umask();
>  	error = dir->i_op->tmpfile(mnt_userns, dir, child, mode);
>  	if (error)
>  		goto out_err;
> -- 
> 2.27.0
>