[LTP] [PATCH v2 8/8] Add ioctl_pidfd06 test

[Andrea Cervesato]

From: Andrea Cervesato <andrea.cervesato@suse.com>

Verify that ioctl() doesn't allow to obtain the exit status of an
isolated process via PIDFD_INFO_EXIT in within an another isolated
process, which doesn't have any parent connection.

Signed-off-by: Andrea Cervesato <andrea.cervesato@suse.com>
---
 runtest/syscalls                                |  1 +
 testcases/kernel/syscalls/ioctl/.gitignore      |  1 +
 testcases/kernel/syscalls/ioctl/ioctl_pidfd06.c | 59 +++++++++++++++++++++++++
 3 files changed, 61 insertions(+)

diff --git a/runtest/syscalls b/runtest/syscalls
index 91908312df82f677e6fa711653b56de8e5ccf016..dd4e92da286c1683807abdd35f271e37fa796bef 100644
--- a/runtest/syscalls
+++ b/runtest/syscalls
@@ -617,6 +617,7 @@ ioctl_pidfd02 ioctl_pidfd02
 ioctl_pidfd03 ioctl_pidfd03
 ioctl_pidfd04 ioctl_pidfd04
 ioctl_pidfd05 ioctl_pidfd05
+ioctl_pidfd06 ioctl_pidfd06
 
 inotify_init1_01 inotify_init1_01
 inotify_init1_02 inotify_init1_02
diff --git a/testcases/kernel/syscalls/ioctl/.gitignore b/testcases/kernel/syscalls/ioctl/.gitignore
index 4658173eac337a8e9cae1844340f9ecc0e55218f..396fe62da37246e0d32f469a519dae98b4fab3d9 100644
--- a/testcases/kernel/syscalls/ioctl/.gitignore
+++ b/testcases/kernel/syscalls/ioctl/.gitignore
@@ -34,3 +34,4 @@
 /ioctl_pidfd03
 /ioctl_pidfd04
 /ioctl_pidfd05
+/ioctl_pidfd06
diff --git a/testcases/kernel/syscalls/ioctl/ioctl_pidfd06.c b/testcases/kernel/syscalls/ioctl/ioctl_pidfd06.c
new file mode 100644
index 0000000000000000000000000000000000000000..6d77982eced49929caecc8280d7091a18aa8ac02
--- /dev/null
+++ b/testcases/kernel/syscalls/ioctl/ioctl_pidfd06.c
@@ -0,0 +1,59 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) 2025 Andrea Cervesato <andrea.cervesato@suse.com>
+ */
+
+/*\
+ * Verify that ioctl() doesn't allow to obtain the exit status of an isolated
+ * process via PIDFD_INFO_EXIT in within an another isolated process, which
+ * doesn't have any parent connection.
+ */
+
+#include "tst_test.h"
+#include "lapi/pidfd.h"
+#include "lapi/sched.h"
+
+static struct tst_clone_args *args;
+static struct pidfd_info *info;
+
+static void run(void)
+{
+	int pidfd;
+	pid_t pid_child;
+
+	memset(args, 0, sizeof(struct tst_clone_args));
+	memset(info, 0, sizeof(struct pidfd_info));
+
+	info->mask = PIDFD_INFO_EXIT;
+
+	args->flags = CLONE_PIDFD | CLONE_NEWUSER | CLONE_NEWPID;
+	args->pidfd = (uint64_t)&pidfd;
+	args->exit_signal = SIGCHLD;
+
+	pid_child = SAFE_CLONE(args);
+	if (!pid_child)
+		exit(100);
+
+	SAFE_WAITPID(pid_child, NULL, 0);
+
+	memset(args, 0, sizeof(struct tst_clone_args));
+
+	args->flags = CLONE_NEWUSER | CLONE_NEWPID;
+	args->exit_signal = SIGCHLD;
+
+	if (!SAFE_CLONE(args)) {
+		TST_EXP_FAIL(ioctl(pidfd, PIDFD_GET_INFO, info), ESRCH);
+		exit(0);
+	}
+}
+
+static struct tst_test test = {
+	.test_all = run,
+	.forks_child = 1,
+	.min_kver = "6.15",
+	.bufs = (struct tst_buffers []) {
+		{&args, .size = sizeof(*args)},
+		{&info, .size = sizeof(*info)},
+		{}
+	}
+};

-- 
2.50.0