leds: wm831x-status: fix use-after-free on unbind

commit 47a459ecc800a17109d0c496a4e21e478806ee40 upstream.

Several MFD child drivers register their class devices directly under
the parent device. This means you cannot blindly do devres conversions
so that deregistration ends up being tied to the parent device,
something which leads to use-after-free on driver unbind when the class
device is released while still being registered.

Fixes: 8d3b6a4001 ("leds: wm831x-status: Use devm_led_classdev_register")
Cc: stable <stable@vger.kernel.org>     # 4.6
Cc: Amitoj Kaur Chawla <amitoj1606@gmail.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Johan Hovold 2020-06-01 15:39:49 +02:00 committed by Greg Kroah-Hartman
parent ab1a602a9c
commit 8bac431d23

View File

@ -273,12 +273,23 @@ static int wm831x_status_probe(struct platform_device *pdev)
drvdata->cdev.blink_set = wm831x_status_blink_set; drvdata->cdev.blink_set = wm831x_status_blink_set;
drvdata->cdev.groups = wm831x_status_groups; drvdata->cdev.groups = wm831x_status_groups;
ret = devm_led_classdev_register(wm831x->dev, &drvdata->cdev); ret = led_classdev_register(wm831x->dev, &drvdata->cdev);
if (ret < 0) { if (ret < 0) {
dev_err(&pdev->dev, "Failed to register LED: %d\n", ret); dev_err(&pdev->dev, "Failed to register LED: %d\n", ret);
return ret; return ret;
} }
platform_set_drvdata(pdev, drvdata);
return 0;
}
static int wm831x_status_remove(struct platform_device *pdev)
{
struct wm831x_status *drvdata = platform_get_drvdata(pdev);
led_classdev_unregister(&drvdata->cdev);
return 0; return 0;
} }
@ -287,6 +298,7 @@ static struct platform_driver wm831x_status_driver = {
.name = "wm831x-status", .name = "wm831x-status",
}, },
.probe = wm831x_status_probe, .probe = wm831x_status_probe,
.remove = wm831x_status_remove,
}; };
module_platform_driver(wm831x_status_driver); module_platform_driver(wm831x_status_driver);