From: Oliver Neukum <oneukum@suse.com>
Date: Thu, 23 Nov 2017 15:39:52 +0000 (+0100)
Subject: USB: usbfs: Filter flags passed in from user space
X-Git-Tag: v3.2.100~127
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=3e7e28e317d9b9d7b04179b7b285234ffa527b22;p=thirdparty%2Fkernel%2Fstable.git

USB: usbfs: Filter flags passed in from user space

commit 446f666da9f019ce2ffd03800995487e79a91462 upstream.

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>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---

diff --git a/drivers/usb/core/devio.c b/drivers/usb/core/devio.c
index caf710028b30f..a33e3cbe67de4 100644
--- a/drivers/usb/core/devio.c
+++ b/drivers/usb/core/devio.c
@@ -1093,14 +1093,18 @@ static int proc_do_submiturb(struct dev_state *ps, struct usbdevfs_urb *uurb,
 	unsigned int u, totlen, isofrmlen;
 	int ret, ifnum = -1;
 	int is_in;
-
-	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 (uurb->buffer_length > 0 && !uurb->buffer)
 		return -EINVAL;
 	if (!(uurb->type == USBDEVFS_URB_TYPE_CONTROL &&