From 44843695bc4e36abd15835d627da7d38c06f2219 Mon Sep 17 00:00:00 2001
From: Konstantin Belousov <kib@FreeBSD.org>
Date: Mon, 16 Feb 2026 12:04:26 +0200
Subject: [PATCH] pdrfork(2) tests: catch runaway child for EFAULT test

Reported and tested by:	pho
Reviewed by:	markj
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
Differential revision:	https://reviews.freebsd.org/D55306
---
 tests/sys/kern/pdrfork.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/tests/sys/kern/pdrfork.c b/tests/sys/kern/pdrfork.c
index 1003ad9dc74..943e7fde835 100644
--- a/tests/sys/kern/pdrfork.c
+++ b/tests/sys/kern/pdrfork.c
@@ -95,11 +95,21 @@ ATF_TC_WITHOUT_HEAD(efault);
 ATF_TC_BODY(efault, tc)
 {
 	void *unmapped;
+	pid_t my_pid;
 
 	unmapped = mmap(NULL, PAGE_SIZE, PROT_NONE, MAP_GUARD, -1, 0);
 	ATF_REQUIRE(unmapped != MAP_FAILED);
+	my_pid = getpid();
 	ATF_REQUIRE_ERRNO(EFAULT, pdrfork(unmapped, 0, RFPROC |
 	    RFPROCDESC) < 0);
+
+	/*
+	 * EFAULT only means that the copyout of the procdesc failed.
+	 * The runaway child was created anyway.  Prevent
+	 * double-destruction of the atf stuff.
+	 */
+	if (my_pid != getpid())
+		_exit(0);
 }
 
 /* Invalid combinations of flags should return EINVAL */