4.9-stable review patch. If anyone has any objections, please let me know.
------------------ From: Eric W. Biederman <ebied...@xmission.com> commit b9a985db98961ae1ba0be169f19df1c567e4ffe0 upstream. 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 <vo...@google.com> Reported-by: Guenter Roeck <li...@roeck-us.net> Tested-by: Guenter Roeck <li...@roeck-us.net> Fixes: 6347e9009104 ("pidns: guarantee that the pidns init will be the last pidns process reaped") Signed-off-by: "Eric W. Biederman" <ebied...@xmission.com> Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org> --- kernel/pid_namespace.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/kernel/pid_namespace.c +++ b/kernel/pid_namespace.c @@ -274,7 +274,7 @@ void zap_pid_ns_processes(struct pid_nam * if reparented. */ for (;;) { - set_current_state(TASK_UNINTERRUPTIBLE); + set_current_state(TASK_INTERRUPTIBLE); if (pid_ns->nr_hashed == init_pids) break; schedule();