usbdevfs: get rid of field-by-field copyin

Al Viro · Al Viro · commit cc1a7c4bae28 · 2017-06-29T18:17:52.000-04:00
Signed-off-by: Al Viro &lt;viro@zeniv.linux.org.uk&gt;
diff --git a/drivers/usb/core/devio.c b/drivers/usb/core/devio.c
@@ -1966,27 +1966,21 @@ static int proc_disconnectsignal_compat(struct usb_dev_state *ps, void __user *a
 static int get_urb32(struct usbdevfs_urb *kurb,
 		     struct usbdevfs_urb32 __user *uurb)
 {
-	__u32  uptr;
-	if (!access_ok(VERIFY_READ, uurb, sizeof(*uurb)) ||
-	    __get_user(kurb->type, &uurb->type) ||
-	    __get_user(kurb->endpoint, &uurb->endpoint) ||
-	    __get_user(kurb->status, &uurb->status) ||
-	    __get_user(kurb->flags, &uurb->flags) ||
-	    __get_user(kurb->buffer_length, &uurb->buffer_length) ||
-	    __get_user(kurb->actual_length, &uurb->actual_length) ||
-	    __get_user(kurb->start_frame, &uurb->start_frame) ||
-	    __get_user(kurb->number_of_packets, &uurb->number_of_packets) ||
-	    __get_user(kurb->error_count, &uurb->error_count) ||
-	    __get_user(kurb->signr, &uurb->signr))
+	struct usbdevfs_urb32 urb32;
+	if (copy_from_user(&urb32, uurb, sizeof(*uurb)))
 		return -EFAULT;
-
-	if (__get_user(uptr, &uurb->buffer))
-		return -EFAULT;
-	kurb->buffer = compat_ptr(uptr);
-	if (__get_user(uptr, &uurb->usercontext))
-		return -EFAULT;
-	kurb->usercontext = compat_ptr(uptr);
-
+	kurb->type = urb32.type;
+	kurb->endpoint = urb32.endpoint;
+	kurb->status = urb32.status;
+	kurb->flags = urb32.flags;
+	kurb->buffer = compat_ptr(urb32.buffer);
+	kurb->buffer_length = urb32.buffer_length;
+	kurb->actual_length = urb32.actual_length;
+	kurb->start_frame = urb32.start_frame;
+	kurb->number_of_packets = urb32.number_of_packets;
+	kurb->error_count = urb32.error_count;
+	kurb->signr = urb32.signr;
+	kurb->usercontext = compat_ptr(urb32.usercontext);
 	return 0;
 }
 
@@ -2198,18 +2192,14 @@ static int proc_ioctl_default(struct usb_dev_state *ps, void __user *arg)
 #ifdef CONFIG_COMPAT
 static int proc_ioctl_compat(struct usb_dev_state *ps, compat_uptr_t arg)
 {
-	struct usbdevfs_ioctl32 __user *uioc;
+	struct usbdevfs_ioctl32 ioc32;
 	struct usbdevfs_ioctl ctrl;
-	u32 udata;
 
-	uioc = compat_ptr((long)arg);
-	if (!access_ok(VERIFY_READ, uioc, sizeof(*uioc)) ||
-	    __get_user(ctrl.ifno, &uioc->ifno) ||
-	    __get_user(ctrl.ioctl_code, &uioc->ioctl_code) ||
-	    __get_user(udata, &uioc->data))
+	if (copy_from_user(&ioc32, compat_ptr(arg), sizeof(ioc32)))
 		return -EFAULT;
-	ctrl.data = compat_ptr(udata);
-
+	ctrl.ifno = ioc32.ifno;
+	ctrl.ioctl_code = ioc32.ioctl_code;
+	ctrl.data = compat_ptr(ioc32.data);
 	return proc_ioctl(ps, &ctrl);
 }
 #endif
