Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
IronPort-SDR: SATrK+f+aqQczKjrXx43vHFHoMWael5mZpRbuh3T0nxTPNNbBwSI3rb3cVKvoXTl6XLy8jjYP6
 o4Ku3GtJ3Gvw==
IronPort-SDR: 8+bUHXn2S5GBUnIYcgAzabJaDshi2Df9aXOOBl4rS8SroGk+W9D13jd5jsB5VK0UtKasj9sQi5
 JDikYO7oaT8g==
From:   Andy Shevchenko <andriy.shevchenko@linux.intel.com>
To:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        linux-kernel@vger.kernel.org,
        "Rafael J. Wysocki" <rafael@kernel.org>
Cc:     Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
        Qu Wenruo <quwenruo.btrfs@gmx.com>,
        Heikki Krogerus <heikki.krogerus@linux.intel.com>
Subject: [PATCH v2] kobject: Restore old behaviour of kobject_del(NULL)
Date:   Mon,  3 Aug 2020 11:27:06 +0300
Message-Id: <20200803082706.65347-1-andriy.shevchenko@linux.intel.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

The commit 079ad2fb4bf9 ("kobject: Avoid premature parent object freeing in
kobject_cleanup()") inadvertently dropped a possibility to call kobject_del()
with NULL pointer. Restore the old behaviour.

Fixes: 079ad2fb4bf9 ("kobject: Avoid premature parent object freeing in kobject_cleanup()")
Reported-by: Qu Wenruo <quwenruo.btrfs@gmx.com>
Cc: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
v2: replaced ?: with plain conditional (Greg)
 lib/kobject.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/lib/kobject.c b/lib/kobject.c
index 3afb939f2a1c..9dce68c378e6 100644
--- a/lib/kobject.c
+++ b/lib/kobject.c
@@ -637,8 +637,12 @@ static void __kobject_del(struct kobject *kobj)
  */
 void kobject_del(struct kobject *kobj)
 {
-	struct kobject *parent = kobj->parent;
+	struct kobject *parent;
+
+	if (!kobj)
+		return;
 
+	parent = kobj->parent;
 	__kobject_del(kobj);
 	kobject_put(parent);
 }
-- 
2.27.0