ghsa-h976-8v6c-8j56
Vulnerability from github
Published
2024-07-16 12:30
Modified
2024-07-16 12:30
Details

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.

Show details on source website

To clipboard 

{
   affected: [],
   aliases: [
      "CVE-2022-48815",
   ],
   database_specific: {
      cwe_ids: [],
      github_reviewed: false,
      github_reviewed_at: null,
      nvd_published_at: "2024-07-16T12:15:05Z",
      severity: null,
   },
   details: "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: dsa: bcm_sf2: don't use devres for mdiobus\n\nAs explained in commits:\n74b6d7d13307 (\"net: dsa: realtek: register the MDIO bus under devres\")\n5135e96a3dd2 (\"net: dsa: don't allocate the slave_mii_bus using devres\")\n\nmdiobus_free() will panic when called from devm_mdiobus_free() <-\ndevres_release_all() <- __device_release_driver(), and that mdiobus was\nnot previously unregistered.\n\nThe Starfighter 2 is a platform device, so the initial set of\nconstraints that I thought would cause this (I2C or SPI buses which call\n->remove on ->shutdown) do not apply. But there is one more which\napplies here.\n\nIf the DSA master itself is on a bus that calls ->remove from ->shutdown\n(like dpaa2-eth, which is on the fsl-mc bus), there is a device link\nbetween the switch and the DSA master, and device_links_unbind_consumers()\nwill unbind the bcm_sf2 switch driver on shutdown.\n\nSo the same treatment must be applied to all DSA switch drivers, which\nis: either use devres for both the mdiobus allocation and registration,\nor don't use devres at all.\n\nThe bcm_sf2 driver has the code structure in place for orderly mdiobus\nremoval, so just replace devm_mdiobus_alloc() with the non-devres\nvariant, and add manual free where necessary, to ensure that we don't\nlet devres free a still-registered bus.",
   id: "GHSA-h976-8v6c-8j56",
   modified: "2024-07-16T12:30:40Z",
   published: "2024-07-16T12:30:40Z",
   references: [
      {
         type: "ADVISORY",
         url: "https://nvd.nist.gov/vuln/detail/CVE-2022-48815",
      },
      {
         type: "WEB",
         url: "https://git.kernel.org/stable/c/08e1a3554e99a1a5bd2835907381e2383ee85cae",
      },
      {
         type: "WEB",
         url: "https://git.kernel.org/stable/c/08f1a20822349004bb9cc1b153ecb516e9f2889d",
      },
      {
         type: "WEB",
         url: "https://git.kernel.org/stable/c/2770b795294ed312375c11ef1d0b810499c66b83",
      },
      {
         type: "WEB",
         url: "https://git.kernel.org/stable/c/caabb5f64f5c32fceed93356bb688ef1ec6c5783",
      },
   ],
   schema_version: "1.4.0",
   severity: [],
}


Log in or create an account to share your comment.

Security Advisory comment format.

This schema specifies the format of a comment related to a security advisory.

UUIDv4 of the comment
UUIDv4 of the Vulnerability-Lookup instance
When the comment was created originally
When the comment was last updated
Title of the comment
Description of the comment
The identifier of the vulnerability (CVE ID, GHSA-ID, PYSEC ID, etc.).



Tags
Taxonomy of the tags.




Sightings

Author Source Type Date

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
  • Confirmed: The vulnerability is confirmed from an analyst perspective.
  • Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
  • Patched: This vulnerability was successfully patched by the user reporting the sighting.
  • Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
  • Not confirmed: The user expresses doubt about the veracity of the vulnerability.
  • Not patched: This vulnerability was not successfully patched by the user reporting the sighting.