linux-kernel - [PATCH v2 1/2] kernel/nsproxy: remove unnecessary guards

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20250508184930.183040-2-jsavitz@redhat.com>
Date: Thu,  8 May 2025 14:49:29 -0400
From: Joel Savitz <jsavitz@...hat.com>
To: linux-kernel@...r.kernel.org
Cc: Joel Savitz <jsavitz@...hat.com>,
	Tejun Heo <tj@...nel.org>,
	Johannes Weiner <hannes@...xchg.org>,
	Michal Koutný <mkoutny@...e.com>,
	Christian Brauner <brauner@...nel.org>,
	Al Viro <viro@...iv.linux.org.uk>,
	cgroups@...r.kernel.org
Subject: [PATCH v2 1/2] kernel/nsproxy: remove unnecessary guards

In free_nsproxy() and the error path of create_new_namesapces() the
put_*_ns() calls are guarded by unnecessary NULL checks.

put_pid_ns(), put_ipc_ns(), put_uts_ns(), and put_time_ns() will never
receive a NULL argument unless their namespace type is disabled, and in
this case all four become no-ops at compile time anyway. put_mnt_ns()
will never receive a null argument at any time.

This unguarded usage is in line with other call sites of put_*_ns().

Signed-off-by: Joel Savitz <jsavitz@...hat.com>
---
 kernel/nsproxy.c | 30 ++++++++++--------------------
 1 file changed, 10 insertions(+), 20 deletions(-)

diff --git a/kernel/nsproxy.c b/kernel/nsproxy.c
index c9d97ed20122..5f31fdff8a38 100644
--- a/kernel/nsproxy.c
+++ b/kernel/nsproxy.c
@@ -128,17 +128,13 @@ static struct nsproxy *create_new_namespaces(unsigned long flags,
 out_net:
 	put_cgroup_ns(new_nsp->cgroup_ns);
 out_cgroup:
-	if (new_nsp->pid_ns_for_children)
-		put_pid_ns(new_nsp->pid_ns_for_children);
+	put_pid_ns(new_nsp->pid_ns_for_children);
 out_pid:
-	if (new_nsp->ipc_ns)
-		put_ipc_ns(new_nsp->ipc_ns);
+	put_ipc_ns(new_nsp->ipc_ns);
 out_ipc:
-	if (new_nsp->uts_ns)
-		put_uts_ns(new_nsp->uts_ns);
+	put_uts_ns(new_nsp->uts_ns);
 out_uts:
-	if (new_nsp->mnt_ns)
-		put_mnt_ns(new_nsp->mnt_ns);
+	put_mnt_ns(new_nsp->mnt_ns);
 out_ns:
 	kmem_cache_free(nsproxy_cachep, new_nsp);
 	return ERR_PTR(err);
@@ -189,18 +185,12 @@ int copy_namespaces(unsigned long flags, struct task_struct *tsk)
 
 void free_nsproxy(struct nsproxy *ns)
 {
-	if (ns->mnt_ns)
-		put_mnt_ns(ns->mnt_ns);
-	if (ns->uts_ns)
-		put_uts_ns(ns->uts_ns);
-	if (ns->ipc_ns)
-		put_ipc_ns(ns->ipc_ns);
-	if (ns->pid_ns_for_children)
-		put_pid_ns(ns->pid_ns_for_children);
-	if (ns->time_ns)
-		put_time_ns(ns->time_ns);
-	if (ns->time_ns_for_children)
-		put_time_ns(ns->time_ns_for_children);
+	put_mnt_ns(ns->mnt_ns);
+	put_uts_ns(ns->uts_ns);
+	put_ipc_ns(ns->ipc_ns);
+	put_pid_ns(ns->pid_ns_for_children);
+	put_time_ns(ns->time_ns);
+	put_time_ns(ns->time_ns_for_children);
 	put_cgroup_ns(ns->cgroup_ns);
 	put_net(ns->net_ns);
 	kmem_cache_free(nsproxy_cachep, ns);
-- 
2.45.2