[PATCH v2 1/9] can: ems_usb: ems_usb_disconnect(): fix NULL pointer dereference

From: Vincent Mailhol
Date: Sat Dec 10 2022 - 04:03:43 EST


ems_usb sets the driver's priv data to NULL before waiting for the
completion of outsdanding urbs. This can results in NULL pointer
dereference, c.f. [1] and [2].

Remove the call to usb_set_intfdata(intf, NULL). The core will take
care of setting it to NULL after ems_usb_disconnect() at [3].

[1] c/27ef17849779 ("usb: add usb_set_intfdata() documentation")
Link: https://git.kernel.org/gregkh/usb/c/27ef17849779

[2] thread about usb_set_intfdata() on linux-usb mailing.
Link: https://lore.kernel.org/linux-usb/Y4OD70GD4KnoRk0k@xxxxxxxxxxxxxxxxxxx/

[3] function usb_unbind_interface() from drivers/usb/core/driver.c
Link: https://elixir.bootlin.com/linux/v6.0/source/drivers/usb/core/driver.c#L497

Fixes: 702171adeed3 ("ems_usb: Added support for EMS CPC-USB/ARM7 CAN/USB interface")
Signed-off-by: Vincent Mailhol <mailhol.vincent@xxxxxxxxxx>
---
drivers/net/can/usb/ems_usb.c | 2 --
1 file changed, 2 deletions(-)

diff --git a/drivers/net/can/usb/ems_usb.c b/drivers/net/can/usb/ems_usb.c
index 050c0b49938a..c64cb40ac8de 100644
--- a/drivers/net/can/usb/ems_usb.c
+++ b/drivers/net/can/usb/ems_usb.c
@@ -1062,8 +1062,6 @@ static void ems_usb_disconnect(struct usb_interface *intf)
{
struct ems_usb *dev = usb_get_intfdata(intf);

- usb_set_intfdata(intf, NULL);
-
if (dev) {
unregister_netdev(dev->netdev);

--
2.37.4