[PATCH AUTOSEL 4.19 02/81] iio: adc: xilinx: fix potential use-after-free on probe

From: Sasha Levin
Date: Tue May 07 2019 - 02:02:35 EST

From: Sven Van Asbroeck <thesven73@xxxxxxxxx>

[ Upstream commit 862e4644fd2d7df8998edc65e0963ea2f567bde9 ]

If probe errors out after request_irq(), its error path
does not explicitly cancel the delayed work, which may
have been scheduled by the interrupt handler.

This means the delayed work may still be running when
the core frees the private structure (struct xadc).
This is a potential use-after-free.

Fix by inserting cancel_delayed_work_sync() in the probe
error path.

Signed-off-by: Sven Van Asbroeck <TheSven73@xxxxxxxxx>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
drivers/iio/adc/xilinx-xadc-core.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/drivers/iio/adc/xilinx-xadc-core.c b/drivers/iio/adc/xilinx-xadc-core.c
index 1960694e8007..15e1a103f37d 100644
--- a/drivers/iio/adc/xilinx-xadc-core.c
+++ b/drivers/iio/adc/xilinx-xadc-core.c
@@ -1290,6 +1290,7 @@ static int xadc_probe(struct platform_device *pdev)

free_irq(xadc->irq, indio_dev);
+ cancel_delayed_work_sync(&xadc->zynq_unmask_work);