[PATCH] iio: chemical: atlas-sensor: use iio_trigger_poll_nested() to fix remove UAF

The atlas driver requests its hardware data-ready IRQ with
devm_request_threaded_irq(); its threaded handler queues an irq_work,
atlas_work_handler(), that calls iio_trigger_poll(data->trig).

The IRQ is devm-managed, so free_irq() runs from the devres unwind after
atlas_remove() returns without flushing that irq_work.  Once a buffer is
enabled, conversion-complete IRQs keep firing and queueing it; a pending
irq_work can therefore run after the unwind has freed atlas_data/indio_dev
and the trigger, when atlas_work_handler() derives the atlas_data pointer
via container_of() and dereferences data->trig, a use-after-free.

Call iio_trigger_poll_nested() directly from the threaded handler instead
of bouncing through irq_work.  free_irq() then drains the threaded handler,
closing the window; other iio drivers with a threaded data-ready IRQ do the
same (e.g. bmi270).

This issue was found by an in-house static analysis tool.

Fixes: 7103b99b031c ("iio: chemical: atlas-ph-sensor: reorg driver to allow multiple chips")
Cc: [email protected] # v6.4+
Assisted-by: Codex:gpt-5.6
Signed-off-by: Fan Wu <[email protected]>
---

 drivers/iio/chemical/atlas-sensor.c | 13 +------------
 1 file changed, 1 insertion(+), 12 deletions(-)

diff --git a/drivers/iio/chemical/atlas-sensor.c b/drivers/iio/chemical/atlas-sensor.c
--- a/drivers/iio/chemical/atlas-sensor.c
+++ b/drivers/iio/chemical/atlas-sensor.c
@@ -13,7 +13,6 @@
 #include <linux/mutex.h>
 #include <linux/err.h>
 #include <linux/irq.h>
-#include <linux/irq_work.h>
 #include <linux/i2c.h>
 #include <linux/mod_devicetable.h>
 #include <linux/regmap.h>
@@ -88,7 +87,6 @@ struct atlas_data {
 	struct iio_trigger *trig;
 	const struct atlas_device *chip;
 	struct regmap *regmap;
-	struct irq_work work;
 	unsigned int interrupt_enabled;
 	/* 96-bit data + 32-bit pad + 64-bit timestamp */
 	__be32 buffer[6] __aligned(8);
@@ -437,13 +435,6 @@ static const struct iio_buffer_setup_ops atlas_buffer_setup_ops = {
 	.predisable = atlas_buffer_predisable,
 };

-static void atlas_work_handler(struct irq_work *work)
-{
-	struct atlas_data *data = container_of(work, struct atlas_data, work);
-
-	iio_trigger_poll(data->trig);
-}
-
 static irqreturn_t atlas_trigger_handler(int irq, void *private)
 {
 	struct iio_poll_func *pf = private;
@@ -470,7 +461,7 @@ static irqreturn_t atlas_interrupt_handler(int irq, void *private)
 	struct iio_dev *indio_dev = private;
 	struct atlas_data *data = iio_priv(indio_dev);

-	irq_work_queue(&data->work);
+	iio_trigger_poll_nested(data->trig);

 	return IRQ_HANDLED;
 }
@@ -666,8 +657,6 @@ static int atlas_probe(struct i2c_client *client)
 		goto unregister_trigger;
 	}

-	init_irq_work(&data->work, atlas_work_handler);
-
 	if (client->irq > 0) {
 		/* interrupt pin toggles on new conversion */
 		ret = devm_request_threaded_irq(&client->dev, client->irq,
--
2.43.0