cd9c790de2
It turns out access to j1939_can_rx_register() needs to be serialized,
otherwise j1939_priv can be corrupted when parallel threads call
j1939_netdev_start() and j1939_can_rx_register() fails. This issue is
thoroughly covered in other commit which serializes access to
j1939_can_rx_register().
Change j1939_netdev_lock type to mutex so that we do not need to remove
GFP_KERNEL from can_rx_register().
j1939_netdev_lock seems to be used in normal contexts where mutex usage
is not prohibited.
Found by Linux Verification Center (linuxtesting.org) with Syzkaller.
Fixes: 9d71dd0c7009 ("can: add support of SAE J1939 protocol")
Suggested-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
Signed-off-by: Fedor Pchelkin <pchelkin@ispras.ru>
Tested-by: Oleksij Rempel <o.rempel@pengutronix.de>
Acked-by: Oleksij Rempel <o.rempel@pengutronix.de>
Link: https://lore.kernel.org/r/20230526171910.227615-2-pchelkin@ispras.ru
Cc: stable@vger.kernel.org
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.