178a09b0fb
commit fc846e9db67c7e808d77bf9e2ef3d49e3820ce5d upstream.
The `INSN_CONFIG` comedi instruction with sub-instruction code
`INSN_CONFIG_DIGITAL_TRIG` includes a base channel in `data[3]`. This is
used as a right shift amount for other bitmask values without being
checked. Shift amounts greater than or equal to 32 will result in
undefined behavior. Add code to deal with this, adjusting the checks
for invalid channels so that enabled channel bits that would have been
lost by shifting are also checked for validity. Only channels 0 to 15
are valid.
Fixes: a8c66b684efaf ("staging: comedi: addi_apci_1500: rewrite the subdevice support functions")
Cc: <stable@vger.kernel.org> #4.0+: ef75e14a6c93: staging: comedi: verify array index is correct before using it
Cc: <stable@vger.kernel.org> #4.0+
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Link: https://lore.kernel.org/r/20200717145257.112660-5-abbotti@mev.co.uk
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.