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.
Vendor | Product | Version | CPE |
---|---|---|---|
linux | linux_kernel | * | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
[
{
"product": "Linux",
"vendor": "Linux",
"defaultStatus": "unaffected",
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"programFiles": [
"drivers/net/dsa/qca/ar9331.c"
],
"versions": [
{
"version": "ac3a68d56651",
"lessThan": "475ce5dcf2d8",
"status": "affected",
"versionType": "git"
},
{
"version": "ac3a68d56651",
"lessThan": "aae1c6a1d3d6",
"status": "affected",
"versionType": "git"
},
{
"version": "ac3a68d56651",
"lessThan": "f1842a8cb71d",
"status": "affected",
"versionType": "git"
},
{
"version": "ac3a68d56651",
"lessThan": "50facd86e9fb",
"status": "affected",
"versionType": "git"
}
]
},
{
"product": "Linux",
"vendor": "Linux",
"defaultStatus": "affected",
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"programFiles": [
"drivers/net/dsa/qca/ar9331.c"
],
"versions": [
{
"version": "5.9",
"status": "affected"
},
{
"version": "0",
"lessThan": "5.9",
"status": "unaffected",
"versionType": "custom"
},
{
"version": "5.10.101",
"lessThanOrEqual": "5.10.*",
"status": "unaffected",
"versionType": "custom"
},
{
"version": "5.15.24",
"lessThanOrEqual": "5.15.*",
"status": "unaffected",
"versionType": "custom"
},
{
"version": "5.16.10",
"lessThanOrEqual": "5.16.*",
"status": "unaffected",
"versionType": "custom"
},
{
"version": "5.17",
"lessThanOrEqual": "*",
"status": "unaffected",
"versionType": "original_commit_for_fix"
}
]
}
]