[6/8] can: ucan: ucan_disconnect(): fix NULL pointer dereference

Message ID 20221203133159.94414-7-mailhol.vincent@wanadoo.fr
State New
Headers
Series can: usb: remove all usb_set_intfdata(intf, NULL) in drivers' disconnect() |

Commit Message

Vincent Mailhol Dec. 3, 2022, 1:31 p.m. UTC
  ucan sets the usb_interface to NULL before waiting for the completion
of outstanding urbs. This can result 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 ucan_disconnect() at [3].

[1] commit 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@rowland.harvard.edu/

[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: 9f2d3eae88d2 ("can: ucan: add driver for Theobroma Systems UCAN devices")
Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
---
 drivers/net/can/usb/ucan.c | 2 --
 1 file changed, 2 deletions(-)
  

Patch

diff --git a/drivers/net/can/usb/ucan.c b/drivers/net/can/usb/ucan.c
index ffa38f533c35..429b3519ee7f 100644
--- a/drivers/net/can/usb/ucan.c
+++ b/drivers/net/can/usb/ucan.c
@@ -1579,8 +1579,6 @@  static void ucan_disconnect(struct usb_interface *intf)
 {
 	struct ucan_priv *up = usb_get_intfdata(intf);
 
-	usb_set_intfdata(intf, NULL);
-
 	if (up) {
 		unregister_candev(up->netdev);
 		free_candev(up->netdev);