In the Linux kernel, the following vulnerability has been resolved:
net: dsa: ar9331: register the mdiobus under devres
As explained in commits:
74b6d7d13307 (“net: dsa: realtek: register the MDIO bus under devres”)
5135e96a3dd2 (“net: dsa: don’t allocate the slave_mii_bus using devres”)
mdiobus_free() will panic when called from devm_mdiobus_free() <-
devres_release_all() <- __device_release_driver(), and that mdiobus was
not previously unregistered.
The ar9331 is an MDIO device, so the initial set of constraints that I
thought would cause this (I2C or SPI buses which call ->remove on
->shutdown) do not apply. But there is one more which applies here.
If the DSA master itself is on a bus that calls ->remove from ->shutdown
(like dpaa2-eth, which is on the fsl-mc bus), there is a device link
between the switch and the DSA master, and device_links_unbind_consumers()
will unbind the ar9331 switch driver on shutdown.
So the same treatment must be applied to all DSA switch drivers, which
is: either use devres for both the mdiobus allocation and registration,
or don’t use devres at all.
The ar9331 driver doesn’t have a complex code structure for mdiobus
removal, so just replace of_mdiobus_register with the devres variant in
order to be all-devres and ensure that we don’t free a still-registered
bus.
OS | Version | Architecture | Package | Version | Filename |
---|---|---|---|---|---|
ubuntu | 20.04 | noarch | linux-intel-iotg-5.15 | < any | UNKNOWN |
git.kernel.org/linus/50facd86e9fbc4b93fe02e5fe05776047f45dbfb (5.17-rc4)
git.kernel.org/stable/c/475ce5dcf2d88fd4f3c213a0ac944e3e40702970
git.kernel.org/stable/c/50facd86e9fbc4b93fe02e5fe05776047f45dbfb
git.kernel.org/stable/c/aae1c6a1d3d696fc33b609fb12fe744a556d1dc5
git.kernel.org/stable/c/f1842a8cb71de4d7eb75a86f76e88c7ee739218c
launchpad.net/bugs/cve/CVE-2022-48817
nvd.nist.gov/vuln/detail/CVE-2022-48817
security-tracker.debian.org/tracker/CVE-2022-48817
www.cve.org/CVERecord?id=CVE-2022-48817