From: Sven Van Asbroeck thesven73@gmail.com
[ Upstream commit f22b1ba15ee5785aa028384ebf77dd39e8e47b70 ]
The device's remove() attempts to shut down the delayed_work scheduled on the kernel-global workqueue by calling flush_scheduled_work().
Unfortunately, flush_scheduled_work() does not prevent the delayed_work from re-scheduling itself. The delayed_work might run after the device has been removed, and touch the already de-allocated info structure. This is a potential use-after-free.
Fix by calling cancel_delayed_work_sync() during remove(): this ensures that the delayed work is properly cancelled, is no longer running, and is not able to re-schedule itself.
This issue was detected with the help of Coccinelle.
Signed-off-by: Sven Van Asbroeck TheSven73@gmail.com Signed-off-by: Alexandre Belloni alexandre.belloni@bootlin.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/rtc/rtc-88pm860x.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/rtc/rtc-88pm860x.c b/drivers/rtc/rtc-88pm860x.c index 01ffc0ef8033f..fbcf13bbbd8d1 100644 --- a/drivers/rtc/rtc-88pm860x.c +++ b/drivers/rtc/rtc-88pm860x.c @@ -414,7 +414,7 @@ static int pm860x_rtc_remove(struct platform_device *pdev) struct pm860x_rtc_info *info = platform_get_drvdata(pdev);
#ifdef VRTC_CALIBRATION - flush_scheduled_work(); + cancel_delayed_work_sync(&info->calib_work); /* disable measurement */ pm860x_set_bits(info->i2c, PM8607_MEAS_EN2, MEAS2_VRTC, 0); #endif /* VRTC_CALIBRATION */