Commit b9a985db authored May 11, 2017 by Eric W. Biederman

pid_ns: Sleep in TASK_INTERRUPTIBLE in zap_pid_ns_processes



The code can potentially sleep for an indefinite amount of time in
zap_pid_ns_processes triggering the hung task timeout, and increasing
the system average.  This is undesirable.  Sleep with a task state of
TASK_INTERRUPTIBLE instead of TASK_UNINTERRUPTIBLE to remove these
undesirable side effects.

Apparently under heavy load this has been allowing Chrome to trigger
the hung time task timeout error and cause ChromeOS to reboot.

Reported-by: Vovo Yang <vovoy@google.com>
Reported-by: Guenter Roeck <linux@roeck-us.net>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Fixes: 6347e900 ("pidns: guarantee that the pidns init will be the last pidns process reaped")
Cc: stable@vger.kernel.org
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>

parent 2ea659a9

kernel/pid_namespace.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -277,7 +277,7 @@ void zap_pid_ns_processes(struct pid_namespace *pid_ns)
		* if reparented.
		*/
		for (;;) {
		set_current_state(TASK_UNINTERRUPTIBLE);
		set_current_state(TASK_INTERRUPTIBLE);
		if (pid_ns->nr_hashed == init_pids)
		break;
		schedule();

Admin message