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From:   Chuansheng Liu <chuansheng.liu@intel.com>
To:     linux-kernel@vger.kernel.org
Cc:     rafael@kernel.org, srinivas.pandruvada@linux.intel.com,
        rui.zhang@intel.com
Subject: [PATCH] thermal: int340x: fix memory leak in int3400_notify()
Date:   Tue, 22 Feb 2022 10:00:21 +0800
Message-Id: <20220222020021.19640-1-chuansheng.liu@intel.com>
MIME-Version: 1.0
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It is easy to hit the below memory leaks in my TigerLake platform:

--
unreferenced object 0xffff927c8b91dbc0 (size 32):
  comm "kworker/0:2", pid 112, jiffies 4294893323 (age 83.604s)
  hex dump (first 32 bytes):
    4e 41 4d 45 3d 49 4e 54 33 34 30 30 20 54 68 65  NAME=INT3400 The
    72 6d 61 6c 00 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b a5  rmal.kkkkkkkkkk.
  backtrace:
    [<ffffffff9c502c3e>] __kmalloc_track_caller+0x2fe/0x4a0
    [<ffffffff9c7b7c15>] kvasprintf+0x65/0xd0
    [<ffffffff9c7b7d6e>] kasprintf+0x4e/0x70
    [<ffffffffc04cb662>] int3400_notify+0x82/0x120 [int3400_thermal]
    [<ffffffff9c8b7358>] acpi_ev_notify_dispatch+0x54/0x71
    [<ffffffff9c88f1a7>] acpi_os_execute_deferred+0x17/0x30
    [<ffffffff9c2c2c0a>] process_one_work+0x21a/0x3f0
    [<ffffffff9c2c2e2a>] worker_thread+0x4a/0x3b0
    [<ffffffff9c2cb4dd>] kthread+0xfd/0x130
    [<ffffffff9c201c1f>] ret_from_fork+0x1f/0x30
---

Fix it by calling kfree() accordingly.

Signed-off-by: Chuansheng Liu <chuansheng.liu@intel.com>
---
 drivers/thermal/intel/int340x_thermal/int3400_thermal.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/thermal/intel/int340x_thermal/int3400_thermal.c b/drivers/thermal/intel/int340x_thermal/int3400_thermal.c
index 72acb1f61849..4f478812cb51 100644
--- a/drivers/thermal/intel/int340x_thermal/int3400_thermal.c
+++ b/drivers/thermal/intel/int340x_thermal/int3400_thermal.c
@@ -404,6 +404,10 @@ static void int3400_notify(acpi_handle handle,
 	thermal_prop[3] = kasprintf(GFP_KERNEL, "EVENT=%d", therm_event);
 	thermal_prop[4] = NULL;
 	kobject_uevent_env(&priv->thermal->device.kobj, KOBJ_CHANGE, thermal_prop);
+	kfree(thermal_prop[0]);
+	kfree(thermal_prop[1]);
+	kfree(thermal_prop[2]);
+	kfree(thermal_prop[3]);
 }
 
 static int int3400_thermal_get_temp(struct thermal_zone_device *thermal,
-- 
2.25.0.rc2