USB: usbfs: Filter flags passed in from user space

USBDEVFS_URB_ISO_ASAP must be accepted only for ISO endpoints.
Improve sanity checking.

Reported-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Oliver Neukum <oneukum@suse.com>
Cc: stable <stable@vger.kernel.org>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 9 insertions, 5 deletions

diff --git a/drivers/usb/core/devio.c b/drivers/usb/core/devio.c
index 705c573d0257..a3fad4ec9870 100644
--- a/drivers/usb/core/devio.c
+++ b/drivers/usb/core/devio.c
@@ -1442,14 +1442,18 @@ static int proc_do_submiturb(struct usb_dev_state *ps, struct usbdevfs_urb *uurb
         int number_of_packets = 0;
         unsigned int stream_id = 0;
         void *buf;
-
-        if (uurb->flags & ~(USBDEVFS_URB_ISO_ASAP |
-                                USBDEVFS_URB_SHORT_NOT_OK |
+        unsigned long mask =    USBDEVFS_URB_SHORT_NOT_OK |
                                 USBDEVFS_URB_BULK_CONTINUATION |
                                 USBDEVFS_URB_NO_FSBR |
                                 USBDEVFS_URB_ZERO_PACKET |
-                                USBDEVFS_URB_NO_INTERRUPT))
-                return -EINVAL;
+                                USBDEVFS_URB_NO_INTERRUPT;
+        /* USBDEVFS_URB_ISO_ASAP is a special case */
+        if (uurb->type == USBDEVFS_URB_TYPE_ISO)
+                mask |= USBDEVFS_URB_ISO_ASAP;
+
+        if (uurb->flags & ~mask)
+                        return -EINVAL;
+
         if ((unsigned int)uurb->buffer_length >= USBFS_XFER_MAX)
                 return -EINVAL;
         if (uurb->buffer_length > 0 && !uurb->buffer)