Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Unverified Commit 67f7b278 authored by Johan Hovold's avatar Johan Hovold Committed by Mark Brown
Browse files

spi: fix use-after-free at controller deregistration 



The controller is typically freed as part of device_unregister() so
store the bus id before deregistration to avoid use-after-free when the
id is later released.

Fixes: 9b61e302 ("spi: Pick spi bus number from Linux idr or spi alias")
Signed-off-by: default avatarJohan Hovold <johan@kernel.org>
Signed-off-by: default avatarMark Brown <broonie@kernel.org>
Cc: stable <stable@vger.kernel.org>
parent 2bd6bf03

drivers/spi/spi.c

+3 −2
Original line number Original line Diff line number Diff line
@@ -2240,11 +2240,12 @@ static int __unregister(struct device *dev, void *null) 
void spi_unregister_controller(struct spi_controller *ctlr)

void spi_unregister_controller(struct spi_controller *ctlr)

{

{

	struct spi_controller *found;

	struct spi_controller *found;

	int id = ctlr->bus_num;

	int dummy;

	int dummy;





	/* First make sure that this controller was ever added */

	/* First make sure that this controller was ever added */

	mutex_lock(&board_lock);

	mutex_lock(&board_lock);

	found = idr_find(&spi_master_idr, ctlr->bus_num);

	found = idr_find(&spi_master_idr, id);

	mutex_unlock(&board_lock);

	mutex_unlock(&board_lock);

	if (found != ctlr) {

	if (found != ctlr) {

		dev_dbg(&ctlr->dev,

		dev_dbg(&ctlr->dev,
@@ -2264,7 +2265,7 @@ void spi_unregister_controller(struct spi_controller *ctlr) 
	device_unregister(&ctlr->dev);

	device_unregister(&ctlr->dev);

	/* free bus id */

	/* free bus id */

	mutex_lock(&board_lock);

	mutex_lock(&board_lock);

	idr_remove(&spi_master_idr, ctlr->bus_num);

	idr_remove(&spi_master_idr, id);

	mutex_unlock(&board_lock);

	mutex_unlock(&board_lock);

}

}

EXPORT_SYMBOL_GPL(spi_unregister_controller);

EXPORT_SYMBOL_GPL(spi_unregister_controller);