Fallback from pidfd_open on permission errors too

Skip using pidfds if we get a permission denied error.
This can happen with an old policy and a new kernel that uses the
new pidfs filesystem to back pidfds, instead of anonymous inodes,
as the existing policy denies access.

This is already the case for most uses of pidfd_open, like pidref,
but not on these two. Fix them.

diff --git a/src/login/pam_systemd.c b/src/login/pam_systemd.c
index 9aa298c6542ca01720bb5bb65c533827fe2203cb..2ea3f6c85089d4a242609e8823a0475b08987d5e 100644 (file)
--- a/src/login/pam_systemd.c
+++ b/src/login/pam_systemd.c
@@ -835,7 +835,7 @@ static int create_session_message(
 
         if (!avoid_pidfd) {
                 pidfd = pidfd_open(getpid_cached(), 0);
-                if (pidfd < 0 && !ERRNO_IS_NOT_SUPPORTED(errno))
+                if (pidfd < 0 && !ERRNO_IS_NOT_SUPPORTED(errno) && !ERRNO_IS_PRIVILEGE(errno))
                         return -errno;
         }
 

diff --git a/src/systemctl/systemctl-show.c b/src/systemctl/systemctl-show.c
index e81afee058f8982ebc40643f41952a3af0eb28bd..999e08b16e896c553d46e7d8bd4da86f7dcfb6b2 100644 (file)
--- a/src/systemctl/systemctl-show.c
+++ b/src/systemctl/systemctl-show.c
@@ -2261,7 +2261,7 @@ static int get_unit_dbus_path_by_pid(
          * sends the numeric PID. */
 
         pidfd = pidfd_open(pid, 0);
-        if (pidfd < 0 && ERRNO_IS_NOT_SUPPORTED(errno))
+        if (pidfd < 0 && ERRNO_IS_NOT_SUPPORTED(errno) && !ERRNO_IS_PRIVILEGE(errno))
                 return get_unit_dbus_path_by_pid_fallback(bus, pid, ret_path, ret_unit);
         if (pidfd < 0)
                 return log_error_errno(errno, "Failed to open PID %"PRIu32": %m", pid);