Commit b4f63322 authored Apr 23, 2020 by Linus Torvalds

user-namespace

Pull SIGCHLD fix from Eric Biederman:
 "Christof Meerwald reported that do_notify_parent has not been
  successfully populating si_pid and si_uid for multi-threaded
  processes.

  This is the one-liner fix. Strictly speaking a one-liner plus
  comment"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
  signal: Avoid corrupting si_pid and si_uid in do_notify_parent

parents 25b1fa8d 61e713bd

kernel/signal.c

+5 −1

Original line number	Diff line number	Diff line
		@@ -1989,8 +1989,12 @@ bool do_notify_parent(struct task_struct *tsk, int sig)
		if (psig->action[SIGCHLD-1].sa.sa_handler == SIG_IGN)
		sig = 0;
		}
		/*
		* Send with __send_signal as si_pid and si_uid are 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);
		__wake_up_parent(tsk, tsk->parent);
		spin_unlock_irqrestore(&psig->siglock, flags);

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