CVE-2022-48815

2024-07-1612:15:05

Linux

web.nvd.nist.gov

linux kernel

vulnerability

net: dsa: bcm_sf2

devres

mdiobus allocation

registration

bcm_sf2 driver

manual free

AI Score

6.7

Confidence

High

EPSS

Percentile

16.0%

JSON

In the Linux kernel, the following vulnerability has been resolved:

net: dsa: bcm_sf2: don’t use devres for mdiobus

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 Starfighter 2 is a platform 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 bcm_sf2 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 bcm_sf2 driver has the code structure in place for orderly mdiobus
removal, so just replace devm_mdiobus_alloc() with the non-devres
variant, and add manual free where necessary, to ensure that we don’t
let devres free a still-registered bus.

Affected configurations

Vulners

Node

linuxlinux_kernelRange5.9–5.10.101

linuxlinux_kernelRange5.11.0–5.15.24

linuxlinux_kernelRange5.16.0–5.16.10

linuxlinux_kernelRange5.17.0≥

VendorProductVersionCPE
linuxlinux_kernel*cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*

Vendor	Product	Version	CPE
linux	linux_kernel	*	cpe:2.3:o:linux:linux_kernel::::::::

CNA Affected

[
  {
    "product": "Linux",
    "vendor": "Linux",
    "defaultStatus": "unaffected",
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "programFiles": [
      "drivers/net/dsa/bcm_sf2.c"
    ],
    "versions": [
      {
        "version": "ac3a68d56651",
        "lessThan": "2770b795294e",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "ac3a68d56651",
        "lessThan": "caabb5f64f5c",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "ac3a68d56651",
        "lessThan": "08e1a3554e99",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "ac3a68d56651",
        "lessThan": "08f1a2082234",
        "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/bcm_sf2.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"
      }
    ]
  }
]