Subject: Re: [PATCH v1 1/4] [RFC] fs/trampfd: Implement the trampoline file descriptor API

From: Oleg Nesterov <[email-masked]>
Date: Tue, 28 Jul 2020 16:50:14 +0200

On 07/28, [email-masked] wrote:
>
> +bool is_trampfd_vma(struct vm_area_struct *vma)
> +{
> +	struct file	*file = vma->vm_file;
> +
> +	if (!file)
> +		return false;
> +	return !strcmp(file->f_path.dentry->d_name.name, trampfd_name);

Hmm, this looks obviously wrong or I am totally confused. A user can
create a file named "[trampfd]", mmap it, and fool trampfd_fault() ?

Why not

	return file->f_op == trampfd_fops;

?

> +EXPORT_SYMBOL_GPL(is_trampfd_vma);

why is it exported?

Oleg.

_______________________________________________
linux-arm-kernel mailing list
[email-masked]
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel