Re: [PATCH] USB: serial: xr: fix NULL-deref on disconnect

From
Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Date
2021-02-26 10:55:38
Also in
lkml
Reply to
Johan Hovold, 2021-02-26
Em Fri, 26 Feb 2021 11:08:26 +0100
Johan Hovold [off-list ref] escreveu:
Claiming the sibling control interface is a bit more involved and
specifically requires adding support to USB-serial core for managing
either interface being unbound first, something which could otherwise
lead to a NULL-pointer dereference.

Similarly, additional infrastructure is also needed to handle suspend
properly.

Since the driver currently isn't actually using the control interface,
we can defer this for now by simply not claiming the control interface.

Fixes: c2d405aa86b4 ("USB: serial: add MaxLinear/Exar USB to Serial driver")
Reported-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Cc: Manivannan Sadhasivam <mani@kernel.org>
Signed-off-by: Johan Hovold <johan@kernel.org>
That solved the issue with XR21V1410:

	[ 8176.265862] usbcore: registered new interface driver xr_serial
	[ 8176.265885] usbserial: USB Serial support registered for xr_serial
	[ 8176.265921] xr_serial 2-1:1.1: xr_serial converter detected
	[ 8176.266041] usb 2-1: xr_serial converter now attached to ttyUSB0
	[ 8176.268023] printk: console [ttyUSB0] enabled
	[ 8186.512841] usb 2-1: USB disconnect, device number 5
	[ 8186.513131] printk: console [ttyUSB0] disabled
	[ 8186.513340] xr_serial ttyUSB0: xr_serial converter now disconnected from ttyUSB0
	[ 8186.513376] xr_serial 2-1:1.1: device disconnected

Tested-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

Regards,
Mauro
quoted hunk ↗ jump to hunk
---
 drivers/usb/serial/xr_serial.c | 25 -------------------------
 1 file changed, 25 deletions(-)
diff --git a/drivers/usb/serial/xr_serial.c b/drivers/usb/serial/xr_serial.c
index 483d07dee19d..0ca04906da4b 100644
--- a/drivers/usb/serial/xr_serial.c
+++ b/drivers/usb/serial/xr_serial.c
@@ -545,37 +545,13 @@ static void xr_close(struct usb_serial_port *port)
 
 static int xr_probe(struct usb_serial *serial, const struct usb_device_id *id)
 {
-	struct usb_driver *driver = serial->type->usb_driver;
-	struct usb_interface *control_interface;
-	int ret;
-
 	/* Don't bind to control interface */
 	if (serial->interface->cur_altsetting->desc.bInterfaceNumber == 0)
 		return -ENODEV;
 
-	/* But claim the control interface during data interface probe */
-	control_interface = usb_ifnum_to_if(serial->dev, 0);
-	if (!control_interface)
-		return -ENODEV;
-
-	ret = usb_driver_claim_interface(driver, control_interface, NULL);
-	if (ret) {
-		dev_err(&serial->interface->dev, "Failed to claim control interface\n");
-		return ret;
-	}
-
 	return 0;
 }
 
-static void xr_disconnect(struct usb_serial *serial)
-{
-	struct usb_driver *driver = serial->type->usb_driver;
-	struct usb_interface *control_interface;
-
-	control_interface = usb_ifnum_to_if(serial->dev, 0);
-	usb_driver_release_interface(driver, control_interface);
-}
-
 static const struct usb_device_id id_table[] = {
 	{ USB_DEVICE(0x04e2, 0x1410) }, /* XR21V141X */
 	{ }
@@ -590,7 +566,6 @@ static struct usb_serial_driver xr_device = {
 	.id_table		= id_table,
 	.num_ports		= 1,
 	.probe			= xr_probe,
-	.disconnect		= xr_disconnect,
 	.open			= xr_open,
 	.close			= xr_close,
 	.break_ctl		= xr_break_ctl,


Thanks,
Mauro
Thread (5 messages) 5 messages, 4 authors, last reply 2021-03-01
Keyboard shortcuts
hback out one level
jnext message in thread / next series-diff position
kprevious message in thread / previous series-diff position
ldrill in
Escclose help / fold thread tree
?toggle this help