In msi2500_probe, it invokes spi_alloc_master to allocate master
controller and spi_register_master to register master controller.
Then in msi2500_disconnect, it calls spi_unregister_master to unregister
the master controller. And in spi_unregister_master, it calls put_device
to decrease the refcount and the device object will be freed then. As a
result, the dereference of dev->lock will cause a use-after-free bug.
Fix it by changing spi_alloc_master to devm_spi_alloc_master, and
removing spi_master_put in the error handling code.
Note that this patch can prevent UAF occurring any more
Fixes: fd8b5f502929 ("msi2500: move msi3101 out of staging and rename")
Signed-off-by: Dongliang Mu <mudongliangabcd@xxxxxxxxx>
---
drivers/media/usb/msi2500/msi2500.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/drivers/media/usb/msi2500/msi2500.c b/drivers/media/usb/msi2500/msi2500.c
index 71de6b4c4e4c..64c3ec9f1d0c 100644
--- a/drivers/media/usb/msi2500/msi2500.c
+++ b/drivers/media/usb/msi2500/msi2500.c
@@ -1220,7 +1220,7 @@ static int msi2500_probe(struct usb_interface *intf,
}
/* SPI master adapter */
- master = spi_alloc_master(dev->dev, 0);
+ master = devm_spi_alloc_master(dev->dev, 0);
if (master == NULL) {
ret = -ENOMEM;
goto err_unregister_v4l2_dev;
@@ -1233,7 +1233,6 @@ static int msi2500_probe(struct usb_interface *intf,
spi_master_set_devdata(master, dev);
ret = spi_register_master(master);
if (ret) {
- spi_master_put(master);
goto err_unregister_v4l2_dev;
}
--
2.25.1
