Thread (10 messages) 10 messages, 3 authors, 2d ago
WARM2d

[PATCH v2 6/7] usb: xusbatm: don't rely on id table pointer arithmetic

From: Gary Guo <gary@garyguo.net>
Date: 2026-07-07 12:27:06
Also in: driver-core, linux-media, linux-usb, linux-wireless, lkml
Subsystem: atm, the rest, usb subsystem · Maintainers: Chas Williams, Linus Torvalds, Greg Kroah-Hartman

The current code is broken when dynamic ID is involved; in such cases
usb_device_id parameter of probe lives on the heap and the pointer
arithmetic will get an index that is wildly out of bound. xusbatm
initialize the USB device IDs dynamically so it can just use driver_info
too.

Even with conversion, xusbatm still cannot support dynamic IDs, so also set
no_dynamic_id.

Signed-off-by: Gary Guo <gary@garyguo.net>
---
 drivers/usb/atm/xusbatm.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/drivers/usb/atm/xusbatm.c b/drivers/usb/atm/xusbatm.c
index 0befbf63d1cc..5c1e1f521555 100644
--- a/drivers/usb/atm/xusbatm.c
+++ b/drivers/usb/atm/xusbatm.c
@@ -79,7 +79,7 @@ static int xusbatm_bind(struct usbatm_data *usbatm,
 			struct usb_interface *intf, const struct usb_device_id *id)
 {
 	struct usb_device *usb_dev = interface_to_usbdev(intf);
-	int drv_ix = id - xusbatm_usb_ids;
+	int drv_ix = id->driver_info;
 	int rx_alt = rx_altsetting[drv_ix];
 	int tx_alt = tx_altsetting[drv_ix];
 	struct usb_interface *rx_intf = xusbatm_find_intf(usb_dev, rx_alt, rx_endpoint[drv_ix]);
@@ -168,7 +168,8 @@ static struct usb_driver xusbatm_usb_driver = {
 	.name		= xusbatm_driver_name,
 	.probe		= xusbatm_usb_probe,
 	.disconnect	= usbatm_usb_disconnect,
-	.id_table	= xusbatm_usb_ids
+	.id_table	= xusbatm_usb_ids,
+	.no_dynamic_id	= 1,
 };
 
 static int __init xusbatm_init(void)
@@ -190,6 +191,7 @@ static int __init xusbatm_init(void)
 		xusbatm_usb_ids[i].match_flags	= USB_DEVICE_ID_MATCH_DEVICE;
 		xusbatm_usb_ids[i].idVendor	= vendor[i];
 		xusbatm_usb_ids[i].idProduct	= product[i];
+		xusbatm_usb_ids[i].driver_info	= i;
 
 		xusbatm_drivers[i].driver_name	= xusbatm_driver_name;
 		xusbatm_drivers[i].bind		= xusbatm_bind;
-- 
2.54.0
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