From: Sasha Levin <sashal@kernel.org>
To: stable@vger.kernel.org
Cc: Christian Brauner <brauner@kernel.org>, Sasha Levin <sashal@kernel.org>
Subject: [PATCH 6.18.y 1/2] pidfs: simplify PIDFD_GET_<type>_NAMESPACE ioctls
Date: Thu, 3 Sep 2026 08:22:35 -0400 [thread overview]
Message-ID: <20260903122236.709194-1-sashal@kernel.org> (raw)
In-Reply-To: <2026090328-fleshed-scrambler-e1f2@gregkh>
From: Christian Brauner <brauner@kernel.org>
[ Upstream commit a71e4f103aed69e7a11ea913312726bb194c76ee ]
We have reworked namespaces sufficiently that all this special-casing
shouldn't be needed anymore
Link: https://patch.msgid.link/20251117-eidesstattlich-apotheke-36d2e644079f@brauner
Signed-off-by: Christian Brauner <brauner@kernel.org>
Stable-dep-of: 9688a4680293 ("pidfd: hold exec_update_lock around namespace ioctl")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
fs/pidfs.c | 75 ++++++++++++++++++++++++++----------------------------
1 file changed, 36 insertions(+), 39 deletions(-)
diff --git a/fs/pidfs.c b/fs/pidfs.c
index 34987fcdd9a87..7282ac3db0795 100644
--- a/fs/pidfs.c
+++ b/fs/pidfs.c
@@ -456,7 +456,6 @@ static long pidfd_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
struct task_struct *task __free(put_task) = NULL;
struct nsproxy *nsp __free(put_nsproxy) = NULL;
struct ns_common *ns_common = NULL;
- struct pid_namespace *pid_ns;
if (!pidfs_ioctl_valid(cmd))
return -ENOIOCTLCMD;
@@ -498,66 +497,64 @@ static long pidfd_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
switch (cmd) {
/* Namespaces that hang of nsproxy. */
case PIDFD_GET_CGROUP_NAMESPACE:
- if (IS_ENABLED(CONFIG_CGROUPS)) {
- get_cgroup_ns(nsp->cgroup_ns);
- ns_common = to_ns_common(nsp->cgroup_ns);
- }
+ if (!ns_ref_get(nsp->cgroup_ns))
+ break;
+ ns_common = to_ns_common(nsp->cgroup_ns);
break;
case PIDFD_GET_IPC_NAMESPACE:
- if (IS_ENABLED(CONFIG_IPC_NS)) {
- get_ipc_ns(nsp->ipc_ns);
- ns_common = to_ns_common(nsp->ipc_ns);
- }
+ if (!ns_ref_get(nsp->ipc_ns))
+ break;
+ ns_common = to_ns_common(nsp->ipc_ns);
break;
case PIDFD_GET_MNT_NAMESPACE:
- get_mnt_ns(nsp->mnt_ns);
+ if (!ns_ref_get(nsp->mnt_ns))
+ break;
ns_common = to_ns_common(nsp->mnt_ns);
break;
case PIDFD_GET_NET_NAMESPACE:
- if (IS_ENABLED(CONFIG_NET_NS)) {
- ns_common = to_ns_common(nsp->net_ns);
- get_net_ns(ns_common);
- }
+ if (!ns_ref_get(nsp->net_ns))
+ break;
+ ns_common = to_ns_common(nsp->net_ns);
break;
case PIDFD_GET_PID_FOR_CHILDREN_NAMESPACE:
- if (IS_ENABLED(CONFIG_PID_NS)) {
- get_pid_ns(nsp->pid_ns_for_children);
- ns_common = to_ns_common(nsp->pid_ns_for_children);
- }
+ if (!ns_ref_get(nsp->pid_ns_for_children))
+ break;
+ ns_common = to_ns_common(nsp->pid_ns_for_children);
break;
case PIDFD_GET_TIME_NAMESPACE:
- if (IS_ENABLED(CONFIG_TIME_NS)) {
- get_time_ns(nsp->time_ns);
- ns_common = to_ns_common(nsp->time_ns);
- }
+ if (!ns_ref_get(nsp->time_ns))
+ break;
+ ns_common = to_ns_common(nsp->time_ns);
break;
case PIDFD_GET_TIME_FOR_CHILDREN_NAMESPACE:
- if (IS_ENABLED(CONFIG_TIME_NS)) {
- get_time_ns(nsp->time_ns_for_children);
- ns_common = to_ns_common(nsp->time_ns_for_children);
- }
+ if (!ns_ref_get(nsp->time_ns_for_children))
+ break;
+ ns_common = to_ns_common(nsp->time_ns_for_children);
break;
case PIDFD_GET_UTS_NAMESPACE:
- if (IS_ENABLED(CONFIG_UTS_NS)) {
- get_uts_ns(nsp->uts_ns);
- ns_common = to_ns_common(nsp->uts_ns);
- }
+ if (!ns_ref_get(nsp->uts_ns))
+ break;
+ ns_common = to_ns_common(nsp->uts_ns);
break;
/* Namespaces that don't hang of nsproxy. */
case PIDFD_GET_USER_NAMESPACE:
- if (IS_ENABLED(CONFIG_USER_NS)) {
- rcu_read_lock();
- ns_common = to_ns_common(get_user_ns(task_cred_xxx(task, user_ns)));
- rcu_read_unlock();
+ scoped_guard(rcu) {
+ struct user_namespace *user_ns;
+
+ user_ns = task_cred_xxx(task, user_ns);
+ if (!ns_ref_get(user_ns))
+ break;
+ ns_common = to_ns_common(user_ns);
}
break;
case PIDFD_GET_PID_NAMESPACE:
- if (IS_ENABLED(CONFIG_PID_NS)) {
- rcu_read_lock();
+ scoped_guard(rcu) {
+ struct pid_namespace *pid_ns;
+
pid_ns = task_active_pid_ns(task);
- if (pid_ns)
- ns_common = to_ns_common(get_pid_ns(pid_ns));
- rcu_read_unlock();
+ if (!ns_ref_get(pid_ns))
+ break;
+ ns_common = to_ns_common(pid_ns);
}
break;
default:
--
2.53.0
next prev parent reply other threads:[~2026-09-03 12:22 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-09-03 9:56 FAILED: patch "[PATCH] pidfd: hold exec_update_lock around namespace ioctl" failed to apply to 6.18-stable tree gregkh
2026-09-03 12:22 ` Sasha Levin [this message]
2026-09-03 12:22 ` [PATCH 6.18.y 2/2] pidfd: hold exec_update_lock around namespace ioctl Sasha Levin
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20260903122236.709194-1-sashal@kernel.org \
--to=sashal@kernel.org \
--cc=brauner@kernel.org \
--cc=stable@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.