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Fix NULL-pointer dereferences at open() and disconnect() should the
device lack the expected bulk-out endpoints:
Unable to handle kernel NULL pointer dereference at virtual address 000000b4
...
[c0170ff0>] (__lock_acquire) from [<c0172f00>] (lock_acquire+0x108/0x264)
[<c0172f00>] (lock_acquire) from [<c06a5090>] (_raw_spin_lock_irqsave+0x58/0x6c)
[<c06a5090>] (_raw_spin_lock_irqsave) from [<c0470684>] (tty_port_tty_set+0x28/0xa4)
[<c0470684>] (tty_port_tty_set) from [<bf08d384>] (omninet_open+0x30/0x40 [omninet])
[<bf08d384>] (omninet_open [omninet]) from [<bf07c118>] (serial_port_activate+0x68/0x98 [usbserial])
Unable to handle kernel NULL pointer dereference at virtual address 00000234
...
[<bf01f418>] (omninet_disconnect [omninet]) from [<bf0016c0>] (usb_serial_disconnect+0xe4/0x100 [usbserial])
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Johan Hovold <johan@kernel.org>
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.