[PATCH 5.4 096/102] platform/chrome: wilco_ec: fix use after free issue

Greg Kroah-Hartman
2020-01-24T09:43:06Z

From: Wen Yang <wenyang@linux.alibaba.com>

[ Upstream commit 856a0a6e2d09d31fd8f00cc1fc6645196a509d56 ]

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
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Signed-off-by: Sasha Levin <sashal@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 b9d03c33d8dc1..1176d543191af 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;
}
--
2.20.1