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From:   Viresh Kumar <viresh.kumar@linaro.org>
To:     "Rafael J. Wysocki" <rafael@kernel.org>,
        Daniel Lezcano <daniel.lezcano@linaro.org>,
        Amit Kucheria <amitk@kernel.org>,
        Zhang Rui <rui.zhang@intel.com>,
        Yang Yingliang <yangyingliang@huawei.com>,
        Viresh Kumar <viresh.kumar@linaro.org>
Cc:     linux-pm@vger.kernel.org,
        Vincent Guittot <vincent.guittot@linaro.org>,
        Caleb Connolly <caleb.connolly@linaro.org>,
        "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>,
        linux-kernel@vger.kernel.org
Subject: [PATCH V4 1/3] thermal: core: call put_device() only after device_register() fails
Date:   Wed, 18 Jan 2023 14:08:24 +0530
Message-Id: <d6e5d4fcca5f66d290e907d10c45cb2e7bbb09e5.1674030722.git.viresh.kumar@linaro.org>
In-Reply-To: <cover.1674030722.git.viresh.kumar@linaro.org>
References: <cover.1674030722.git.viresh.kumar@linaro.org>
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Precedence: bulk

put_device() shouldn't be called before a prior call to
device_register(). __thermal_cooling_device_register() doesn't follow
that properly and needs fixing. Also
thermal_cooling_device_destroy_sysfs() is getting called unnecessarily
on few error paths.

Fix all this by placing the calls at the right place.

Based on initial work done by Caleb Connolly.

Fixes: 4748f9687caa ("thermal: core: fix some possible name leaks in error paths")
Fixes: c408b3d1d9bb ("thermal: Validate new state in cur_state_store()")
Reported-by: Caleb Connolly <caleb.connolly@linaro.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
---
For v6.2-rc.

V3->V4:
- The first three versions were sent by Caleb.
- The new version fixes the current bugs, without looking to optimize the
  code any further, which is done separately in the next two patches.

 drivers/thermal/thermal_core.c | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c
index f17ab2316dbd..77bd47d976a2 100644
--- a/drivers/thermal/thermal_core.c
+++ b/drivers/thermal/thermal_core.c
@@ -909,15 +909,20 @@ __thermal_cooling_device_register(struct device_node *np,
 	cdev->devdata = devdata;
 
 	ret = cdev->ops->get_max_state(cdev, &cdev->max_state);
-	if (ret)
-		goto out_kfree_type;
+	if (ret) {
+		kfree(cdev->type);
+		goto out_ida_remove;
+	}
 
 	thermal_cooling_device_setup_sysfs(cdev);
+
 	ret = dev_set_name(&cdev->device, "cooling_device%d", cdev->id);
 	if (ret) {
+		kfree(cdev->type);
 		thermal_cooling_device_destroy_sysfs(cdev);
-		goto out_kfree_type;
+		goto out_ida_remove;
 	}
+
 	ret = device_register(&cdev->device);
 	if (ret)
 		goto out_kfree_type;
@@ -943,6 +948,8 @@ __thermal_cooling_device_register(struct device_node *np,
 	thermal_cooling_device_destroy_sysfs(cdev);
 	kfree(cdev->type);
 	put_device(&cdev->device);
+
+	/* thermal_release() takes care of the rest */
 	cdev = NULL;
 out_ida_remove:
 	ida_free(&thermal_cdev_ida, id);
-- 
2.31.1.272.g89b43f80a514