Re: [PATCH v2] kthread: fix use-after-free if kthread fork fails

2017-05-10 Thread Oleg Nesterov
On 05/09, Vegard Nossum wrote: > > If a kthread forks (e.g. usermodehelper since commit 1da5c46fa965) but > fails in copy_process() between calling dup_task_struct() and setting > p->set_child_tid, then the value of p->set_child_tid will be inherited > from the parent and get prematurely freed by f

[PATCH v2] kthread: fix use-after-free if kthread fork fails

2017-05-09 Thread Vegard Nossum
If a kthread forks (e.g. usermodehelper since commit 1da5c46fa965) but fails in copy_process() between calling dup_task_struct() and setting p->set_child_tid, then the value of p->set_child_tid will be inherited from the parent and get prematurely freed by free_kthread_struct(). kthread()