[ 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 <thesve...@gmail.com>
Signed-off-by: Alexandre Belloni <alexandre.bell...@bootlin.com>
Signed-off-by: Sasha Levin <sas...@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 */
--
2.20.1
