diff options
| author | Mike Yuan <me@yhndnzj.com> | 2025-06-04 15:03:42 +0000 |
|---|---|---|
| committer | Christian Brauner <brauner@kernel.org> | 2025-06-04 22:48:32 +0200 |
| commit | b55eb6eb2a7427428c59b293a0900131fc849595 (patch) | |
| tree | a71496708bd3d1b3ec9e4de6648f6c7e6b39dea7 | |
| parent | 5abc7438f1e9d62e91ad775cc83c9594c48d2282 (diff) | |
pidfs: never refuse ppid == 0 in PIDFD_GET_INFO
In systemd we spotted an issue after switching to ioctl(PIDFD_GET_INFO)
for obtaining pid number the pidfd refers to, that for processes
with a parent from outer pidns PIDFD_GET_INFO unexpectedly yields
-ESRCH [1]. It turned out that there's an arbitrary check blocking
this, which is not really sensible given getppid() happily returns
0 for such processes. Just drop the spurious check and userspace
ought to handle ppid == 0 properly everywhere.
[1] https://github.com/systemd/systemd/issues/37715
Fixes: cdda1f26e74b ("pidfd: add ioctl to retrieve pid info")
Signed-off-by: Mike Yuan <me@yhndnzj.com>
Link: https://lore.kernel.org/20250604150238.42664-1-me@yhndnzj.com
Cc: Christian Brauner <brauner@kernel.org>
Cc: Luca Boccassi <luca.boccassi@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
| -rw-r--r-- | fs/pidfs.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/pidfs.c b/fs/pidfs.c index c1f0a067be40..69919be1c9d8 100644 --- a/fs/pidfs.c +++ b/fs/pidfs.c @@ -366,7 +366,7 @@ static long pidfd_info(struct file *file, unsigned int cmd, unsigned long arg) kinfo.pid = task_pid_vnr(task); kinfo.mask |= PIDFD_INFO_PID; - if (kinfo.pid == 0 || kinfo.tgid == 0 || (kinfo.ppid == 0 && kinfo.pid != 1)) + if (kinfo.pid == 0 || kinfo.tgid == 0) return -ESRCH; copy_out: |