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From: Chunyan Zhang <chunyan.zhang@unisoc.com>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        "Rafael J . Wysocki"
	<rafael@kernel.org>
CC: LKML <linux-kernel@vger.kernel.org>, Jing Xia <jing.xia@unisoc.com>,
        Jing
 Xia <jing.xia.mail@gmail.com>,
        Xuewen Yan <xuewen.yan@unisoc.com>, Ke Wang
	<ke.wang@unisoc.com>,
        Chunyan Zhang <zhang.lyra@gmail.com>
Subject: [PATCH] class: fix use-after-free in class_register()
Date: Mon, 18 Dec 2023 10:44:03 +0800
Message-ID: <20231218024403.1076134-1-chunyan.zhang@unisoc.com>
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From: Jing Xia <jing.xia@unisoc.com>

The lock_class_key is still registered and can be found in
lock_keys_hash hlist after subsys_private is freed in error
handler path.A task who iterate over the lock_keys_hash
later may cause use-after-free.So fix that up and unregister
the lock_class_key before kfree(cp).

Signed-off-by: Jing Xia <jing.xia@unisoc.com>
Signed-off-by: Xuewen Yan <xuewen.yan@unisoc.com>
---
 drivers/base/class.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/base/class.c b/drivers/base/class.c
index 7e78aee0fd6c..7b38fdf8e1d7 100644
--- a/drivers/base/class.c
+++ b/drivers/base/class.c
@@ -213,6 +213,7 @@ int class_register(const struct class *cls)
 	return 0;
 
 err_out:
+	lockdep_unregister_key(key);
 	kfree(cp);
 	return error;
 }
-- 
2.25.1