linux-kernel - Re: [PATCH v12 2/3] ptrace,syscall_user_dispatch: checkpoint/restore support for SUD

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <CAJwJo6YnELNhU8RmR-z37vDZ=xb0CmUUBgrPGgHP2dqjVm=O2g@mail.gmail.com>
Date:   Mon, 27 Feb 2023 16:02:54 +0000
From:   Dmitry Safonov <0x7f454c46@...il.com>
To:     Gregory Price <gourry.memverge@...il.com>
Cc:     linux-kernel@...r.kernel.org, linux-doc@...r.kernel.org,
        oleg@...hat.com, avagin@...il.com, peterz@...radead.org,
        luto@...nel.org, krisman@...labora.com, tglx@...utronix.de,
        corbet@....net, shuah@...nel.org,
        Gregory Price <gregory.price@...verge.com>
Subject: Re: [PATCH v12 2/3] ptrace,syscall_user_dispatch: checkpoint/restore
 support for SUD

Hi Gragory,

On Fri, 24 Feb 2023 at 23:40, Gregory Price <gourry.memverge@...il.com> wrote:
>
> Implement ptrace getter/setter interface for syscall user dispatch.
>
> These prctl settings are presently write-only, making it impossible to
> implement transparent checkpoint/restore via software like CRIU.
>
> 'on_dispatch' field is not exposed because it is a kernel-internal
> only field that cannot be 'true' when returning to userland.
>
> Signed-off-by: Gregory Price <gregory.price@...verge.com>
> ---
[..]
> +int syscall_user_dispatch_set_config(struct task_struct *task, unsigned long size,
> +                                    void __user *data)
> +{
> +       int rc;
> +       struct ptrace_sud_config cfg;
> +
> +       if (size != sizeof(struct ptrace_sud_config))
> +               return -EINVAL;
> +
> +       if (copy_from_user(&cfg, data, sizeof(struct ptrace_sud_config)))
> +               return -EFAULT;

It seems that the tool you want here would be copy_struct_from_user(),
which is designed for extendable syscalls.

Thanks,
             Dmitry