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From: Tao Cui <cui.tao@linux.dev>
To: brauner@kernel.org
Cc: jack@suse.cz, kees@kernel.org, cyphar@cyphar.com,
	containers@vger.kernel.org, linux-kernel@vger.kernel.org,
	cuitao@kylinos.cn, cui.tao@linux.dev
Subject: [PATCH 1/2] userns: remove dead key_put() on the create_user_ns() error path
Date: Fri, 28 Aug 2026 17:16:58 +0800	[thread overview]
Message-ID: <20260828091659.358700-2-cui.tao@linux.dev> (raw)
In-Reply-To: <20260828091659.358700-1-cui.tao@linux.dev>

From: Tao Cui <cuitao@kylinos.cn>

create_user_ns() jumps to fail_keyring when setup_userns_sysctls()
fails.  At that point ns was freshly allocated with
kmem_cache_zalloc() and ns->persistent_keyring_register is only ever
assigned later, lazily, from key_get_persistent()
(security/keys/persistent.c).  The key_put() therefore always
receives NULL.

Remove the dead call.

Signed-off-by: Tao Cui <cuitao@kylinos.cn>
---
 kernel/user_namespace.c | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/kernel/user_namespace.c b/kernel/user_namespace.c
index 0bed462e9b2a..e9e04ce167df 100644
--- a/kernel/user_namespace.c
+++ b/kernel/user_namespace.c
@@ -162,9 +162,6 @@ int create_user_ns(struct cred *new)
 	ns_tree_add(ns);
 	return 0;
 fail_keyring:
-#ifdef CONFIG_PERSISTENT_KEYRINGS
-	key_put(ns->persistent_keyring_register);
-#endif
 	ns_common_free(ns);
 fail_free:
 	kmem_cache_free(user_ns_cachep, ns);
-- 
2.43.0


  reply	other threads:[~2026-08-28  9:17 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-08-28  9:16 [PATCH 0/2] userns: clean up dead code on error paths Tao Cui
2026-08-28  9:16 ` Tao Cui [this message]
2026-08-28  9:41   ` [PATCH 1/2] userns: remove dead key_put() on the create_user_ns() error path Jan Kara
2026-08-28 11:45   ` Bradley Morgan
2026-08-28  9:16 ` [PATCH 2/2] userns: don't clear the install target map on map_write() failure Tao Cui
2026-08-28  9:51   ` Jan Kara
2026-08-28 13:34   ` Bradley Morgan

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