This driver's remove path calls cancel_delayed_work(). However, that function does not wait until the work function finishes. This could mean that the work function is still running after the driver's remove function has finished, which would result in a use-after-free.

Fix by calling cancel_delayed_work_sync(), which ensures that that the work is properly cancelled, no longer running, and unable to re-schedule itself.

This issue was detected with the help of Coccinelle.

Cc: stable stable@vger.kernel.org Signed-off-by: Sven Van Asbroeck TheSven73@gmail.com --- drivers/power/ltc2941-battery-gauge.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/power/ltc2941-battery-gauge.c b/drivers/power/ltc2941-battery-gauge.c index da49436176cd..30a9014b2f95 100644 --- a/drivers/power/ltc2941-battery-gauge.c +++ b/drivers/power/ltc2941-battery-gauge.c @@ -449,7 +449,7 @@ static int ltc294x_i2c_remove(struct i2c_client *client) { struct ltc294x_info *info = i2c_get_clientdata(client);

- cancel_delayed_work(&info->work); + cancel_delayed_work_sync(&info->work); power_supply_unregister(info->supply); return 0; }

Hi,

On Thu, Sep 19, 2019 at 11:11:37AM -0400, Sven Van Asbroeck wrote:

This driver's remove path calls cancel_delayed_work(). However, that function does not wait until the work function finishes. This could mean that the work function is still running after the driver's remove function has finished, which would result in a use-after-free.

Fix by calling cancel_delayed_work_sync(), which ensures that that the work is properly cancelled, no longer running, and unable to re-schedule itself.

This issue was detected with the help of Coccinelle.

Cc: stable stable@vger.kernel.org Signed-off-by: Sven Van Asbroeck TheSven73@gmail.com

---

Thanks, queued.

-- Sebastian

drivers/power/supply/ltc2941-battery-gauge.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/power/supply/ltc2941-battery-gauge.c b/drivers/power/supply/ltc2941-battery-gauge.c index da49436176cd..30a9014b2f95 100644 --- a/drivers/power/supply/ltc2941-battery-gauge.c +++ b/drivers/power/supply/ltc2941-battery-gauge.c @@ -449,7 +449,7 @@ static int ltc294x_i2c_remove(struct i2c_client *client) { struct ltc294x_info *info = i2c_get_clientdata(client);

• cancel_delayed_work(&info->work);

• cancel_delayed_work_sync(&info->work); power_supply_unregister(info->supply); return 0;

}

2.17.1