ghsa-35q9-qwff-qmh4
Vulnerability from github
Published
2024-05-22 09:31
Modified
2024-10-31 21:31
Severity ?
5.5 (Medium) - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Details

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

net: dsa: microchip: Added the condition for scheduling ksz_mib_read_work

When the ksz module is installed and removed using rmmod, kernel crashes with null pointer dereferrence error. During rmmod, ksz_switch_remove function tries to cancel the mib_read_workqueue using cancel_delayed_work_sync routine and unregister switch from dsa.

During dsa_unregister_switch it calls ksz_mac_link_down, which in turn reschedules the workqueue since mib_interval is non-zero. Due to which queue executed after mib_interval and it tries to access dp->slave. But the slave is unregistered in the ksz_switch_remove function. Hence kernel crashes.

To avoid this crash, before canceling the workqueue, resetted the mib_interval to 0.

v1 -> v2: -Removed the if condition in ksz_mib_read_work

Show details on source website

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{
   affected: [],
   aliases: [
      "CVE-2021-47439",
   ],
   database_specific: {
      cwe_ids: [
         "CWE-476",
      ],
      github_reviewed: false,
      github_reviewed_at: null,
      nvd_published_at: "2024-05-22T07:15:09Z",
      severity: "MODERATE",
   },
   details: "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: dsa: microchip: Added the condition for scheduling ksz_mib_read_work\n\nWhen the ksz module is installed and removed using rmmod, kernel crashes\nwith null pointer dereferrence error. During rmmod, ksz_switch_remove\nfunction tries to cancel the mib_read_workqueue using\ncancel_delayed_work_sync routine and unregister switch from dsa.\n\nDuring dsa_unregister_switch it calls ksz_mac_link_down, which in turn\nreschedules the workqueue since mib_interval is non-zero.\nDue to which queue executed after mib_interval and it tries to access\ndp->slave. But the slave is unregistered in the ksz_switch_remove\nfunction. Hence kernel crashes.\n\nTo avoid this crash, before canceling the workqueue, resetted the\nmib_interval to 0.\n\nv1 -> v2:\n-Removed the if condition in ksz_mib_read_work",
   id: "GHSA-35q9-qwff-qmh4",
   modified: "2024-10-31T21:31:44Z",
   published: "2024-05-22T09:31:44Z",
   references: [
      {
         type: "ADVISORY",
         url: "https://nvd.nist.gov/vuln/detail/CVE-2021-47439",
      },
      {
         type: "WEB",
         url: "https://git.kernel.org/stable/c/383239a33cf29ebee9ce0d4e0e5c900b77a16148",
      },
      {
         type: "WEB",
         url: "https://git.kernel.org/stable/c/ef1100ef20f29aec4e62abeccdb5bdbebba1e378",
      },
      {
         type: "WEB",
         url: "https://git.kernel.org/stable/c/f2e1de075018cf71bcd7d628e9f759cb8540b0c3",
      },
   ],
   schema_version: "1.4.0",
   severity: [
      {
         score: "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
         type: "CVSS_V3",
      },
   ],
}


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