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From: Serge Hallyn <serge.hallyn-Z7WLFzj8eWMS+FvcfC7Uqw@public.gmane.org>
To: Li Zefan <lizefan-hv44wF8Li93QT0dZR+AlfA@public.gmane.org>
Cc: Containers
	<containers-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org>,
	ebiederm-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org,
	LKML <linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>
Subject: Re: [PATCH] userns: Allow unprivileged reboot
Date: Wed, 2 Jan 2013 09:13:44 -0600	[thread overview]
Message-ID: <20130102151344.GA5822@sergelap> (raw)
In-Reply-To: <50DBC2E0.3040908-hv44wF8Li93QT0dZR+AlfA@public.gmane.org>

Quoting Li Zefan (lizefan-hv44wF8Li93QT0dZR+AlfA@public.gmane.org):
> In a container with its own pid namespace and user namespace, rebooting
> the system won't reboot the host, but terminate all the processes in
> it and thus have the container shutdown, so it's safe.
> 
> Signed-off-by: Li Zefan <lizefan-hv44wF8Li93QT0dZR+AlfA@public.gmane.org>

Thanks, Li.

fwiw,
Acked-by: Serge E. Hallyn <serge.hallyn-GeWIH/nMZzLQT0dZR+AlfA@public.gmane.org>

-serge

> ---
>  kernel/sys.c | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/kernel/sys.c b/kernel/sys.c
> index 265b376..24d1ef5 100644
> --- a/kernel/sys.c
> +++ b/kernel/sys.c
> @@ -433,11 +433,12 @@ static DEFINE_MUTEX(reboot_mutex);
>  SYSCALL_DEFINE4(reboot, int, magic1, int, magic2, unsigned int, cmd,
>  		void __user *, arg)
>  {
> +	struct pid_namespace *pid_ns = task_active_pid_ns(current);
>  	char buffer[256];
>  	int ret = 0;
>  
>  	/* We only trust the superuser with rebooting the system. */
> -	if (!capable(CAP_SYS_BOOT))
> +	if (!ns_capable(pid_ns->user_ns, CAP_SYS_BOOT))
>  		return -EPERM;
>  
>  	/* For safety, we require "magic" arguments. */
> @@ -453,7 +454,7 @@ SYSCALL_DEFINE4(reboot, int, magic1, int, magic2, unsigned int, cmd,
>  	 * pid_namespace, the command is handled by reboot_pid_ns() which will
>  	 * call do_exit().
>  	 */
> -	ret = reboot_pid_ns(task_active_pid_ns(current), cmd);
> +	ret = reboot_pid_ns(pid_ns, cmd);
>  	if (ret)
>  		return ret;
>  
> -- 
> 1.8.0.2
> _______________________________________________
> Containers mailing list
> Containers-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org
> https://lists.linuxfoundation.org/mailman/listinfo/containers

WARNING: multiple messages have this Message-ID (diff)
From: Serge Hallyn <serge.hallyn@canonical.com>
To: Li Zefan <lizefan@huawei.com>
Cc: ebiederm@xmission.com,
	Containers <containers@lists.linux-foundation.org>,
	LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] userns: Allow unprivileged reboot
Date: Wed, 2 Jan 2013 09:13:44 -0600	[thread overview]
Message-ID: <20130102151344.GA5822@sergelap> (raw)
In-Reply-To: <50DBC2E0.3040908@huawei.com>

Quoting Li Zefan (lizefan@huawei.com):
> In a container with its own pid namespace and user namespace, rebooting
> the system won't reboot the host, but terminate all the processes in
> it and thus have the container shutdown, so it's safe.
> 
> Signed-off-by: Li Zefan <lizefan@huawei.com>

Thanks, Li.

fwiw,
Acked-by: Serge E. Hallyn <serge.hallyn@ubuntu.com>

-serge

> ---
>  kernel/sys.c | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/kernel/sys.c b/kernel/sys.c
> index 265b376..24d1ef5 100644
> --- a/kernel/sys.c
> +++ b/kernel/sys.c
> @@ -433,11 +433,12 @@ static DEFINE_MUTEX(reboot_mutex);
>  SYSCALL_DEFINE4(reboot, int, magic1, int, magic2, unsigned int, cmd,
>  		void __user *, arg)
>  {
> +	struct pid_namespace *pid_ns = task_active_pid_ns(current);
>  	char buffer[256];
>  	int ret = 0;
>  
>  	/* We only trust the superuser with rebooting the system. */
> -	if (!capable(CAP_SYS_BOOT))
> +	if (!ns_capable(pid_ns->user_ns, CAP_SYS_BOOT))
>  		return -EPERM;
>  
>  	/* For safety, we require "magic" arguments. */
> @@ -453,7 +454,7 @@ SYSCALL_DEFINE4(reboot, int, magic1, int, magic2, unsigned int, cmd,
>  	 * pid_namespace, the command is handled by reboot_pid_ns() which will
>  	 * call do_exit().
>  	 */
> -	ret = reboot_pid_ns(task_active_pid_ns(current), cmd);
> +	ret = reboot_pid_ns(pid_ns, cmd);
>  	if (ret)
>  		return ret;
>  
> -- 
> 1.8.0.2
> _______________________________________________
> Containers mailing list
> Containers@lists.linux-foundation.org
> https://lists.linuxfoundation.org/mailman/listinfo/containers

  parent reply	other threads:[~2013-01-02 15:13 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-12-27  3:39 [PATCH] userns: Allow unprivileged reboot Li Zefan
     [not found] ` <50DBC2E0.3040908-hv44wF8Li93QT0dZR+AlfA@public.gmane.org>
2012-12-27  4:29   ` Eric W. Biederman
2012-12-27  4:29     ` Eric W. Biederman
2013-01-02 15:13   ` Serge Hallyn [this message]
2013-01-02 15:13     ` Serge Hallyn
  -- strict thread matches above, loose matches on Subject: below --
2012-12-27  3:39 Li Zefan

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