786f5b0345
commit 536de747bc48262225889a533db6650731ab25d3 upstream.
USB transfer buffers are typically mapped for DMA and must not be
allocated on the stack or transfers will fail.
Allocate proper transfer buffers in the various command helpers and
return an error on short transfers instead of acting on random stack
data.
Note that this also fixes a stack info leak on systems where DMA is not
used as 32 bytes are always sent to the device regardless of how short
the command is.
Fixes: 63274cd7d38a ("Staging: comedi: add usb dt9812 driver")
Cc: stable@vger.kernel.org # 2.6.29
Reviewed-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20211027093529.30896-3-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.