From: Lei Zhu <[email protected]>
The cmsg_check_dead() function receives an expected_pid parameter but never
actually verifies that the pidfd received via SCM_PIDFD corresponds to that
PID. It only checks the child's exit code via PIDFD_GET_INFO.
Add a PID verification step using get_pid_from_fdinfo_file() to confirm
that the pidfd indeed points to the expected process, matching the
behavior already present in cmsg_check().
Fixes: 861bdc6314a4 ("selftests: net: extend SCM_PIDFD test to cover stale
pidfds")
Signed-off-by: Lei Zhu <[email protected]>
---
tools/testing/selftests/net/af_unix/scm_pidfd.c | 9 ++++++++-
1 file changed, 8 insertions(+), 1 deletion(-)
diff --git a/tools/testing/selftests/net/af_unix/scm_pidfd.c
b/tools/testing/selftests/net/af_unix/scm_pidfd.c
index 2c18b92a2603..bfc99d0c5ac0 100644
--- a/tools/testing/selftests/net/af_unix/scm_pidfd.c
+++ b/tools/testing/selftests/net/af_unix/scm_pidfd.c
@@ -276,8 +276,15 @@ static int cmsg_check_dead(int fd, int expected_pid)
return 1;
}
+ /* pidfd from SCM_PIDFD should point to the client_pid */
+ pid_t pid = get_pid_from_fdinfo_file(*res.pidfd, "Pid:", sizeof("Pid:")
- 1);
+ if (pid != expected_pid) {
+ log_err("wrong SCM_PIDFD %d != %d", pid, expected_pid);
+ close(*res.pidfd);
+ return 1;
+ }
+
/*
- * pidfd from SCM_PIDFD should point to the client_pid.
* Let's read exit information and check if it's what
* we expect to see.
*/
--
2.25.1
