2021-05-17 10:08:55

by Johan Hovold

Subject: [PATCH] HID: magicmouse: fix NULL-deref on disconnect

Commit 9d7b18668956 ("HID: magicmouse: add support for Apple Magic
Trackpad 2") added a sanity check for an Apple trackpad but returned
success instead of -ENODEV when the check failed. This means that the
remove callback will dereference the never-initialised driver data
pointer when the driver is later unbound (e.g. on USB disconnect).

Reported-by: [email protected]
Fixes: 9d7b18668956 ("HID: magicmouse: add support for Apple Magic Trackpad 2")
Cc: [email protected] # 4.20
Cc: Claudio Mettler <[email protected]>
Cc: Marek Wyborski <[email protected]>
Cc: Sean O'Brien <[email protected]>
Signed-off-by: Johan Hovold <[email protected]>
---
drivers/hid/hid-magicmouse.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/hid/hid-magicmouse.c b/drivers/hid/hid-magicmouse.c
index 2bb473d8c424..56dda50aa3d8 100644
--- a/drivers/hid/hid-magicmouse.c
+++ b/drivers/hid/hid-magicmouse.c
@@ -693,7 +693,7 @@ static int magicmouse_probe(struct hid_device *hdev,
if (id->vendor == USB_VENDOR_ID_APPLE &&
id->product == USB_DEVICE_ID_APPLE_MAGICTRACKPAD2 &&
hdev->type != HID_TYPE_USBMOUSE)
- return 0;
+ return -ENODEV;

msc = devm_kzalloc(&hdev->dev, sizeof(*msc), GFP_KERNEL);
if (msc == NULL) {
--
2.26.3

2021-05-26 10:52:55

by Jiri Kosina

Subject: Re: [PATCH] HID: magicmouse: fix NULL-deref on disconnect

On Mon, 17 May 2021, Johan Hovold wrote:

> Commit 9d7b18668956 ("HID: magicmouse: add support for Apple Magic
> Trackpad 2") added a sanity check for an Apple trackpad but returned
> success instead of -ENODEV when the check failed. This means that the
> remove callback will dereference the never-initialised driver data
> pointer when the driver is later unbound (e.g. on USB disconnect).
>
> Reported-by: [email protected]
> Fixes: 9d7b18668956 ("HID: magicmouse: add support for Apple Magic Trackpad 2")
> Cc: [email protected] # 4.20
> Cc: Claudio Mettler <[email protected]>
> Cc: Marek Wyborski <[email protected]>
> Cc: Sean O'Brien <[email protected]>
> Signed-off-by: Johan Hovold <[email protected]>

Applied, thanks Johan.

--
Jiri Kosina
SUSE Labs