[PATCH v2 1/6] selftests/sched_ext: Fix reload_loop error-path use-after-free

[Tao Cui <cui.tao@linux.dev>]

From: Tao Cui <cuitao@kylinos.cn>

If the second pthread_create() fails, run() returns and the runner
calls cleanup, which destroys the skeleton while the first reload
thread is still running do_reload_loop() and dereferencing its maps -
a use-after-free on the error path.

Set force_exit and join the first thread before failing.

Signed-off-by: Tao Cui <cuitao@kylinos.cn>
---
 tools/testing/selftests/sched_ext/reload_loop.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/sched_ext/reload_loop.c b/tools/testing/selftests/sched_ext/reload_loop.c
index 49297b83d748..a00f3964dba0 100644
--- a/tools/testing/selftests/sched_ext/reload_loop.c
+++ b/tools/testing/selftests/sched_ext/reload_loop.c
@@ -53,7 +53,11 @@ static enum scx_test_status run(void *ctx)
 	SCX_FAIL_IF(err, "Failed to create thread 0");
 
 	err = pthread_create(&threads[1], NULL, do_reload_loop, NULL);
-	SCX_FAIL_IF(err, "Failed to create thread 1");
+	if (err) {
+		force_exit = true;
+		pthread_join(threads[0], NULL);
+		SCX_FAIL("Failed to create thread 1");
+	}
 
 	SCX_FAIL_IF(pthread_join(threads[0], &ret), "thread 0 failed");
 	SCX_FAIL_IF(pthread_join(threads[1], &ret), "thread 1 failed");
-- 
2.53.0