Re: [PATCH v2] usb: devio: Add ioctl to disallow detaching kernel USB drivers.
flat view
From: Bjørn Mork <hidden>
Date: 2016-01-22 09:41:58
Also in:
lkml
Emilio López [off-list ref] writes:
quoted hunk
diff --git a/drivers/usb/core/devio.c b/drivers/usb/core/devio.c index 38ae877c..bf40aa6 100644 --- a/drivers/usb/core/devio.c +++ b/drivers/usb/core/devio.c@@ -77,6 +77,8 @@ struct usb_dev_state { unsigned long ifclaimed; u32 secid; u32 disabled_bulk_eps; + bool privileges_dropped; + unsigned long interface_allowed_mask; }; struct async {@@ -641,6 +643,14 @@ static int claimintf(struct usb_dev_state *ps, unsigned int ifnum) if (test_bit(ifnum, &ps->ifclaimed)) return 0; + if (ps->privileges_dropped) { + if (ifnum >= 8*sizeof(ps->interface_allowed_mask)) + return -EINVAL;
I don't think you need this runtime test. You can just make sure that sizeof(ps->interface_allowed_mask) == sizeof(ps->ifclaimed) at build time. I do find this variable and arbitrary limit a bit confusing, but that's not your fault - I guess it is an indication that ifnums > 31 are rare :)
quoted hunk
diff --git a/include/uapi/linux/usbdevice_fs.h b/include/uapi/linux/usbdevice_fs.h index 019ba1e..9abcb34 100644 --- a/include/uapi/linux/usbdevice_fs.h +++ b/include/uapi/linux/usbdevice_fs.h@@ -154,6 +154,10 @@ struct usbdevfs_streams { unsigned char eps[0]; }; +struct usbdevfs_drop_privs { + unsigned long interface_allowed_mask; +}; +
"unsigned long" isn't a very good choice here, is it? Bjørn -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html