2bda24ef95
The gs_usb driver appears to suffer from a malady common to many USB
CAN adapter drivers in that it performs usb_alloc_coherent() to
allocate a number of USB request blocks (URBs) for RX, and then later
relies on usb_kill_anchored_urbs() to free them, but this doesn't
actually free them. As a result, this may be leaking DMA memory that's
been used by the driver.
This commit is an adaptation of the techniques found in the esd_usb2
driver where a similar design pattern led to a memory leak. It
explicitly frees the RX URBs and their DMA memory via a call to
usb_free_coherent(). Since the RX URBs were allocated in the
gs_can_open(), we remove them in gs_can_close() rather than in the
disconnect function as was done in esd_usb2.
For more information, see the 928150fad41b ("can: esd_usb2: fix memory
leak").
Link: https://lore.kernel.org/all/alpine.DEB.2.22.394.2206031547001.1630869@thelappy
Fixes: d08e973a77d1 ("can: gs_usb: Added support for the GS_USB CAN devices")
Cc: stable@vger.kernel.org
Signed-off-by: Rhett Aultman <rhett.aultman@samsara.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
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.