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Commit 923c7538 authored by Li Zefan's avatar Li Zefan Committed by Eric W. Biederman
Browse files

userns: Allow unprivileged reboot 



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: default avatarLi Zefan <lizefan@huawei.com>
Signed-off-by: default avatarEric W. Biederman <ebiederm@xmission.com>
parent 48c6d121

kernel/sys.c

+3 −2
Original line number Diff line number Diff line
@@ -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;