b2fa7baee7
The driver was using its struct usb_device pointer as an inverted
disconnected flag, but was setting it to NULL before making sure all
completion handlers had run. This could lead to a NULL-pointer
dereference in a number of dev_dbg statements in the completion handlers
which relies on said pointer.
The pointer was also dereferenced unconditionally in a dev_dbg statement
release() something which would lead to a NULL-deref whenever a device
was disconnected before the final character-device close if debugging
was enabled.
Fix this by unconditionally stopping all I/O and preventing
resubmissions by poisoning the interrupt URBs at disconnect and using a
dedicated disconnected flag.
This also makes sure that all I/O has completed by the time the
disconnect callback returns.
Fixes: 1ef37c6047fe ("USB: adutux: remove custom debug macro and module parameter")
Fixes: 66d4bc30d128 ("USB: adutux: remove custom debug macro")
Cc: stable <stable@vger.kernel.org> # 3.12
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20190925092913.8608-2-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.