b93eb56486
The probe function sets priv->chip_data to (void *)priv + sizeof(*priv)
with the expectation that priv has enough trailing space.
However, only realtek-smi actually allocated this chip_data space.
Do likewise in realtek-mdio to fix out-of-bounds accesses.
These accesses likely went unnoticed so far, because of an (unused)
buf[4096] member in struct realtek_priv, which caused kmalloc to
round up the allocated buffer to a big enough size, so nothing of
value was overwritten. With a different allocator (like in the barebox
bootloader port of the driver) or with KASAN, the memory corruption
becomes quickly apparent.
Fixes: aac94001067d ("net: dsa: realtek: add new mdio interface for drivers")
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Luiz Angelo Daros de Luca <luizluca@gmail.com>
Reviewed-by: Alvin Šipraga <alsi@bang-olufsen.dk>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
Link: https://lore.kernel.org/r/20230323103735.2331786-1-a.fatoum@pengutronix.de
Signed-off-by: Jakub Kicinski <kuba@kernel.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.