CVE-2022-48817

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> net: dsa: ar9331: register the mdiobus under devres<br /> <br /> As explained in commits:<br /> 74b6d7d13307 ("net: dsa: realtek: register the MDIO bus under devres")<br /> 5135e96a3dd2 ("net: dsa: don&amp;#39;t allocate the slave_mii_bus using devres")<br /> <br /> mdiobus_free() will panic when called from devm_mdiobus_free() shutdown) do not apply. But there is one more which applies here.<br /> <br /> If the DSA master itself is on a bus that calls -&gt;remove from -&gt;shutdown<br /> (like dpaa2-eth, which is on the fsl-mc bus), there is a device link<br /> between the switch and the DSA master, and device_links_unbind_consumers()<br /> will unbind the ar9331 switch driver on shutdown.<br /> <br /> So the same treatment must be applied to all DSA switch drivers, which<br /> is: either use devres for both the mdiobus allocation and registration,<br /> or don&amp;#39;t use devres at all.<br /> <br /> The ar9331 driver doesn&amp;#39;t have a complex code structure for mdiobus<br /> removal, so just replace of_mdiobus_register with the devres variant in<br /> order to be all-devres and ensure that we don&amp;#39;t free a still-registered<br /> bus.