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From: ebiederm@xmission.com (Eric W. Biederman)
To: Oleg Nesterov <oleg@redhat.com>
Cc: Kirill Tkhai <ktkhai@virtuozzo.com>,
	mhocko@suse.com, avagin@openvz.org, peterz@infradead.org,
	linux-kernel@vger.kernel.org, rppt@linux.vnet.ibm.com,
	luto@kernel.org, gorcunov@openvz.org, akpm@linux-foundation.org,
	mingo@kernel.org, serge@hallyn.com
Subject: Re: [PATCH v2] pid_ns: Fix race between setns'ed fork() and zap_pid_ns_processes()
Date: Fri, 12 May 2017 11:34:24 -0500	[thread overview]
Message-ID: <87tw4q11bj.fsf@xmission.com> (raw)
In-Reply-To: <20170512161705.GA18742@redhat.com> (Oleg Nesterov's message of "Fri, 12 May 2017 18:17:06 +0200")

Oleg Nesterov <oleg@redhat.com> writes:

> On 05/12, Kirill Tkhai wrote:
>>
>  --- a/kernel/fork.c
>> +++ b/kernel/fork.c
>> @@ -1845,11 +1845,13 @@ static __latent_entropy struct task_struct *copy_process(
>>  	*/
>>  	recalc_sigpending();
>>  	if (signal_pending(current)) {
>> -		spin_unlock(&current->sighand->siglock);
>> -		write_unlock_irq(&tasklist_lock);
>>  		retval = -ERESTARTNOINTR;
>>  		goto bad_fork_cancel_cgroup;
>>  	}
>> +	if (unlikely(!(ns_of_pid(pid)->nr_hashed & PIDNS_HASH_ADDING))) {
>> +		retval = -ENOMEM;
>> +		goto bad_fork_cancel_cgroup;
>> +	}
>>  
>>  	if (likely(p->pid)) {
>>  		ptrace_init_task(p, (clone_flags & CLONE_PTRACE) || trace);
>> @@ -1907,6 +1909,8 @@ static __latent_entropy struct task_struct *copy_process(
>>  	return p;
>>  
>>  bad_fork_cancel_cgroup:
>> +	spin_unlock(&current->sighand->siglock);
>> +	write_unlock_irq(&tasklist_lock);
>>  	cgroup_cancel_fork(p);
>
> Looks good to me.

Oleg can I have a review or acked by?

Then I will queue this up.
Eric

  reply	other threads:[~2017-05-12 16:40 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-05-12 16:11 [PATCH v2] pid_ns: Fix race between setns'ed fork() and zap_pid_ns_processes() Kirill Tkhai
2017-05-12 16:17 ` Oleg Nesterov
2017-05-12 16:34   ` Eric W. Biederman [this message]
2017-05-12 17:05     ` Oleg Nesterov

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