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From:   Wen Yang <wenyang@linux.alibaba.com>
To:     Benson Leung <bleung@chromium.org>,
        Enric Balletbo i Serra <enric.balletbo@collabora.com>
Cc:     xlpang@linux.alibaba.com, Wen Yang <wenyang@linux.alibaba.com>,
        Nick Crews <ncrews@chromium.org>, linux-kernel@vger.kernel.org
Subject: [PATCH] platform/chrome: wilco_ec: fix use after free issue
Date:   Sat, 30 Nov 2019 21:08:42 +0800
Message-Id: <20191130130842.33763-1-wenyang@linux.alibaba.com>
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Sender: linux-kernel-owner@vger.kernel.org
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This is caused by dereferencing 'dev_data' after put_device() in
the telem_device_remove() function.
This patch just moves the put_device() down a bit to avoid this
issue.

Fixes: 1210d1e6bad1 ("platform/chrome: wilco_ec: Add telemetry char device interface")
Signed-off-by: Wen Yang <wenyang@linux.alibaba.com>
Cc: Benson Leung <bleung@chromium.org>
Cc: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Cc: Nick Crews <ncrews@chromium.org>
Cc: linux-kernel@vger.kernel.org
---
 drivers/platform/chrome/wilco_ec/telemetry.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/platform/chrome/wilco_ec/telemetry.c b/drivers/platform/chrome/wilco_ec/telemetry.c
index b9d03c3..1176d54 100644
--- a/drivers/platform/chrome/wilco_ec/telemetry.c
+++ b/drivers/platform/chrome/wilco_ec/telemetry.c
@@ -406,8 +406,8 @@ static int telem_device_remove(struct platform_device *pdev)
 	struct telem_device_data *dev_data = platform_get_drvdata(pdev);
 
 	cdev_device_del(&dev_data->cdev, &dev_data->dev);
-	put_device(&dev_data->dev);
 	ida_simple_remove(&telem_ida, MINOR(dev_data->dev.devt));
+	put_device(&dev_data->dev);
 
 	return 0;
 }
-- 
1.8.3.1