ghsa-cx6c-r38j-fxp8
Vulnerability from github
Published
2025-02-27 21:32
Modified
2025-02-27 21:32
Severity ?
7.8 (High) - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Details

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

usbnet: Run unregister_netdev() before unbind() again

Commit 2c9d6c2b871d ("usbnet: run unbind() before unregister_netdev()") sought to fix a use-after-free on disconnect of USB Ethernet adapters.

It turns out that a different fix is necessary to address the issue: https://lore.kernel.org/netdev/18b3541e5372bc9b9fc733d422f4e698c089077c.1650177997.git.lukas@wunner.de/

So the commit was not necessary.

The commit made binding and unbinding of USB Ethernet asymmetrical: Before, usbnet_probe() first invoked the ->bind() callback and then register_netdev(). usbnet_disconnect() mirrored that by first invoking unregister_netdev() and then ->unbind().

Since the commit, the order in usbnet_disconnect() is reversed and no longer mirrors usbnet_probe().

One consequence is that a PHY disconnected (and stopped) in ->unbind() is afterwards stopped once more by unregister_netdev() as it closes the netdev before unregistering. That necessitates a contortion in ->stop() because the PHY may only be stopped if it hasn't already been disconnected.

Reverting the commit allows making the call to phy_stop() unconditional in ->stop().

Show details on source website

To clipboard 

{
  "affected": [],
  "aliases": [
    "CVE-2022-49501"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-416"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2025-02-26T07:01:26Z",
    "severity": "HIGH"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nusbnet: Run unregister_netdev() before unbind() again\n\nCommit 2c9d6c2b871d (\"usbnet: run unbind() before unregister_netdev()\")\nsought to fix a use-after-free on disconnect of USB Ethernet adapters.\n\nIt turns out that a different fix is necessary to address the issue:\nhttps://lore.kernel.org/netdev/18b3541e5372bc9b9fc733d422f4e698c089077c.1650177997.git.lukas@wunner.de/\n\nSo the commit was not necessary.\n\nThe commit made binding and unbinding of USB Ethernet asymmetrical:\nBefore, usbnet_probe() first invoked the -\u003ebind() callback and then\nregister_netdev().  usbnet_disconnect() mirrored that by first invoking\nunregister_netdev() and then -\u003eunbind().\n\nSince the commit, the order in usbnet_disconnect() is reversed and no\nlonger mirrors usbnet_probe().\n\nOne consequence is that a PHY disconnected (and stopped) in -\u003eunbind()\nis afterwards stopped once more by unregister_netdev() as it closes the\nnetdev before unregistering.  That necessitates a contortion in -\u003estop()\nbecause the PHY may only be stopped if it hasn\u0027t already been\ndisconnected.\n\nReverting the commit allows making the call to phy_stop() unconditional\nin -\u003estop().",
  "id": "GHSA-cx6c-r38j-fxp8",
  "modified": "2025-02-27T21:32:14Z",
  "published": "2025-02-27T21:32:14Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2022-49501"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/6d5deb242874d924beccf7eb3cef04c1c3b0da79"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/969a1b3ea3cb7d58a16fe12fd1b04bfc0ea40509"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/d1408f6b4dd78fb1b9e26bcf64477984e5f85409"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/fbda837107f9bd4ec658d2aa88c6856dba606f06"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ]
}


Log in or create an account to share your comment.




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.