Re: Re: [PATCH] statmount: Fix the null-ptr-deref in do_statmount()

[Qing Wang]

On Fri, 13 Feb 2026 at 17:38, "Bhavik Sachdev" <b.sachdev1904@xxxxxxxxx> wrote:
> Hey!
> I think the fix should be the following instead, AFAIU we don't want a
> call to an internal mount to succeed.
> 
> diff --git a/fs/namespace.c b/fs/namespace.c
> index a67cbe42746d..55152bf64785 100644
> --- a/fs/namespace.c
> +++ b/fs/namespace.c
> @@ -5678,6 +5678,8 @@ static int do_statmount(struct kstatmount *s, u64 mnt=
> _id, u64 mnt_ns_id,
> 
>                 s->mnt =3D mnt_file->f_path.mnt;
>                 ns =3D real_mount(s->mnt)->mnt_ns;
> +               if (IS_ERR(ns))
> +                       return -EINVAL;
>                 if (!ns)
>                         /*
>                          * We can't set mount point and mnt_ns_id since we =
> don't have a
> 
> Thanks,
> Bhavik

I had considered returning an error code before but finally decided to
not. Thank you for your suggestion, I agree with it and resend the patch
v3 [0].

[0] https://lore.kernel.org/all/20260213103006.2472569-1-wangqing7171@xxxxxxxxx/T/

Look forward to your review.

---
Thanks,
Qing