[PATCH AUTOSEL 5.0 053/317] rtc: 88pm860x: prevent use-after-free on device remove

[PATCH AUTOSEL 5.0 053/317] rtc: 88pm860x: prevent use-after-free on device remove

[Sasha Levin]

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 */
-- 
2.20.1

[PATCH AUTOSEL 5.0 054/317] rtc: stm32: manage the get_irq probe defer case

[Sasha Levin]

From: Fabien Dessenne <fabien.dessenne@st.com>

[ Upstream commit cf612c5949aca2bd81a1e28688957c8149ea2693 ]

Manage the -EPROBE_DEFER error case for the wake IRQ.

Signed-off-by: Fabien Dessenne <fabien.dessenne@st.com>
Acked-by: Amelie Delaunay <amelie.delaunay@st.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/rtc/rtc-stm32.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/drivers/rtc/rtc-stm32.c b/drivers/rtc/rtc-stm32.c
index c5908cfea2340..8e6c9b3bcc29a 100644
--- a/drivers/rtc/rtc-stm32.c
+++ b/drivers/rtc/rtc-stm32.c
@@ -788,11 +788,14 @@ static int stm32_rtc_probe(struct platform_device *pdev)
 	ret = device_init_wakeup(&pdev->dev, true);
 	if (rtc->data->has_wakeirq) {
 		rtc->wakeirq_alarm = platform_get_irq(pdev, 1);
-		if (rtc->wakeirq_alarm <= 0)
-			ret = rtc->wakeirq_alarm;
-		else
+		if (rtc->wakeirq_alarm > 0) {
 			ret = dev_pm_set_dedicated_wake_irq(&pdev->dev,
 							    rtc->wakeirq_alarm);
+		} else {
+			ret = rtc->wakeirq_alarm;
+			if (rtc->wakeirq_alarm == -EPROBE_DEFER)
+				goto err;
+		}
 	}
 	if (ret)
 		dev_warn(&pdev->dev, "alarm can't wake up the system: %d", ret);
-- 
2.20.1