From: Oleg Nesterov <oleg@redhat.com>
To: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: linux-kernel@vger.kernel.org,
Christof Meerwald <cmeerw@cmeerw.org>,
Linux Containers <containers@lists.linux-foundation.org>
Subject: Re: [PATCH] signal: Avoid corrupting si_pid and si_uid in do_notify_parent
Date: Tue, 21 Apr 2020 11:04:27 +0200 [thread overview]
Message-ID: <20200421090426.GA6787@redhat.com> (raw)
In-Reply-To: <87sggyytnh.fsf@x220.int.ebiederm.org>
On 04/20, Eric W. Biederman wrote:
>
> The immediate problem is as Christof noticed that "pid_alive(current) == false".
this is slightly offtopic, but we can probably remove this "pid_alive" check,
pid_nr_ns() checks pid != NULL anyway.
> Inspecting the code it appears this problem has existed since the pid
> namespace support started handling this case
Agreed...
> @@ -1993,8 +1993,12 @@ bool do_notify_parent(struct task_struct *tsk, int sig)
> if (psig->action[SIGCHLD-1].sa.sa_handler == SIG_IGN)
> sig = 0;
> }
> + /*
> + * Bypass send_signal as the si_pid and si_uid values have
> + * been generated in the parent's namespaces.
> + */
> if (valid_signal(sig) && sig)
> - __group_send_sig_info(sig, &info, tsk->parent);
> + __send_signal(sig, &info, tsk->parent, PIDTYPE_TGID, false);
Acked-by: Oleg Nesterov <oleg@redhat.com>
next prev parent reply other threads:[~2020-04-21 9:04 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-19 20:13 SIGCHLD signal sometimes sent with si_pid==0 (Linux 5.6.5) Christof Meerwald
2020-04-20 17:05 ` [PATCH] signal: Avoid corrupting si_pid and si_uid in do_notify_parent Eric W. Biederman
2020-04-21 8:30 ` Christian Brauner
2020-04-21 9:28 ` Oleg Nesterov
2020-04-21 10:21 ` Christian Brauner
2020-04-21 11:11 ` Oleg Nesterov
2020-04-21 11:26 ` Christian Brauner
2020-04-21 12:17 ` Oleg Nesterov
2020-04-21 12:59 ` Christian Brauner
2020-04-21 13:42 ` Eric W. Biederman
2020-04-21 11:28 ` Oleg Nesterov
2020-04-21 11:38 ` Christian Brauner
2020-04-21 10:28 ` Christian Brauner
2020-04-21 14:57 ` Eric W. Biederman
2020-04-21 15:08 ` Christian Brauner
2020-04-21 9:04 ` Oleg Nesterov [this message]
2020-04-21 10:19 ` [PATCH] remove the no longer needed pid_alive() check in __task_pid_nr_ns() Oleg Nesterov
2020-04-21 10:50 ` Christian Brauner
2020-04-21 15:05 ` Eric W. Biederman
2020-04-24 18:05 ` Oleg Nesterov
2020-04-24 19:54 ` Eric W. Biederman
2020-04-21 14:59 ` SIGCHLD signal sometimes sent with si_pid==0 (Linux 5.6.5) Eric W. Biederman
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