Files
linux/drivers/usb
Alan Stern bdbb426f6e USB: fix the usbfs flag sanitization for control transfers
commit 665c365a77 upstream.

Commit 7a68d9fb85 ("USB: usbdevfs: sanitize flags more") checks the
transfer flags for URBs submitted from userspace via usbfs.  However,
the check for whether the USBDEVFS_URB_SHORT_NOT_OK flag should be
allowed for a control transfer was added in the wrong place, before
the code has properly determined the direction of the control
transfer.  (Control transfers are special because for them, the
direction is set by the bRequestType byte of the Setup packet rather
than direction bit of the endpoint address.)

This patch moves code which sets up the allow_short flag for control
transfers down after is_in has been set to the correct value.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Reported-and-tested-by: syzbot+24a30223a4b609bb802e@syzkaller.appspotmail.com
Fixes: 7a68d9fb85 ("USB: usbdevfs: sanitize flags more")
CC: Oliver Neukum <oneukum@suse.com>
CC: <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-11-10 07:43:00 -08:00
..
2015-04-03 19:03:16 +02:00

To understand all the Linux-USB framework, you'll use these resources:

    * This source code.  This is necessarily an evolving work, and
      includes kerneldoc that should help you get a current overview.
      ("make pdfdocs", and then look at "usb.pdf" for host side and
      "gadget.pdf" for peripheral side.)  Also, Documentation/usb has
      more information.

    * The USB 2.0 specification (from www.usb.org), with supplements
      such as those for USB OTG and the various device classes.
      The USB specification has a good overview chapter, and USB
      peripherals conform to the widely known "Chapter 9".

    * Chip specifications for USB controllers.  Examples include
      host controllers (on PCs, servers, and more); peripheral
      controllers (in devices with Linux firmware, like printers or
      cell phones); and hard-wired peripherals like Ethernet adapters.

    * Specifications for other protocols implemented by USB peripheral
      functions.  Some are vendor-specific; others are vendor-neutral
      but just standardized outside of the www.usb.org team.

Here is a list of what each subdirectory here is, and what is contained in
them.

core/		- This is for the core USB host code, including the
		  usbfs files and the hub class driver ("hub_wq").

host/		- This is for USB host controller drivers.  This
		  includes UHCI, OHCI, EHCI, and others that might
		  be used with more specialized "embedded" systems.

gadget/		- This is for USB peripheral controller drivers and
		  the various gadget drivers which talk to them.


Individual USB driver directories.  A new driver should be added to the
first subdirectory in the list below that it fits into.

image/		- This is for still image drivers, like scanners or
		  digital cameras.
../input/	- This is for any driver that uses the input subsystem,
		  like keyboard, mice, touchscreens, tablets, etc.
../media/	- This is for multimedia drivers, like video cameras,
		  radios, and any other drivers that talk to the v4l
		  subsystem.
../net/		- This is for network drivers.
serial/		- This is for USB to serial drivers.
storage/	- This is for USB mass-storage drivers.
class/		- This is for all USB device drivers that do not fit
		  into any of the above categories, and work for a range
		  of USB Class specified devices. 
misc/		- This is for all USB device drivers that do not fit
		  into any of the above categories.