On Tue, 2017-05-23 at 22:09 +0200, Greg Kroah-Hartman wrote: > 4.4-stable review patch. If anyone has any objections, please let me know. > > ------------------ > > From: Eric W. Biederman <ebiederm@xxxxxxxxxxxx> > > 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. [...] This seems to rely on the task not actually being signallable due to the PF_EXITING flag. Using TASK_IDLE would be clearer (though less backport-able). Ben. -- Ben Hutchings Software Developer, Codethink Ltd.