From: Li Zefan Date: Thu, 27 Dec 2012 03:39:12 +0000 (+0800) Subject: userns: Allow unprivileged reboot X-Git-Tag: firefly_0821_release~3680^2~1038^2~92 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=923c7538236564c46ee80c253a416705321f13e3;p=firefly-linux-kernel-4.4.55.git 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: Li Zefan Signed-off-by: Eric W. Biederman --- diff --git a/kernel/sys.c b/kernel/sys.c index 265b37690421..24d1ef56cd95 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;