CVE-2026-98305 (GCVE-0-2026-98305)

Vulnerability from cvelistv5 – Published: 2026-10-06 08:46 – Updated: 2026-10-07 06:49
VLAI
Title
net: dsa: mxl862xx: disable the stats poll on teardown
Summary
In the Linux kernel, the following vulnerability has been resolved: net: dsa: mxl862xx: disable the stats poll on teardown mxl862xx_setup() arms the stats poll before mxl862xx_setup_mdio(), and nothing stops it until dsa_register_switch() has returned an error to mxl862xx_probe(). DSA frees the dsa_port list before it returns, so a poll that fires once .setup or a later step of dsa_tree_setup() has failed walks freed ports. On shutdown the user ports stay registered, and the WORK_STOPPED flag test in mxl862xx_get_stats64() is not atomic with the cancel in mxl862xx_shutdown(), so a re-arm that read the flag before it was set queues the poll after cancel_delayed_work_sync() has returned. Arm the poll once .setup has succeeded and stop it from a .teardown op, which DSA calls on unregister and after a failed registration, in both cases before it frees the ports. Use disable_delayed_work_sync() there and in shutdown(): it drains a running poll as the cancel did and turns every later attempt to queue the work into a no-op, so the re-arm cannot bring the poll back. remove() and the probe error path only set WORK_STOPPED, which crc_err_work tests before it walks the ports.
Severity
7.8 (High)
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Assigner
Linux CNA under the mitre root
CNA scorecard D 54/100 over 6633 records in the last 180 days details
References
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: a21d33a5265f0b31d935a8b9b2b6faefb5185911 , < 97df811a11d4f76bc2ffe67b6bf730263f56c668 (git)
Affected: a21d33a5265f0b31d935a8b9b2b6faefb5185911 , < 9e92ad4630f5dd1838ce6bbe6b1bd2c73d34de36 (git)
guessed Create a notification for this product.
Linux Linux Affected: 7.1
Unaffected: 0 , < 7.1 (semver)
Unaffected: 7.2.8 , ≤ 7.2.* (semver)
Unaffected: 7.3-rc4 , ≤ * (original_commit_for_fix)
guessed Create a notification for this product.
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{
  "containers": {
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      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/net/dsa/mxl862xx/mxl862xx.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
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      "cpeApplicability": [
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                  "versionStartIncluding": "7.1",
                  "vulnerable": true
                },
                {
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              "negate": false,
              "operator": "OR"
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      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: dsa: mxl862xx: disable the stats poll on teardown\n\nmxl862xx_setup() arms the stats poll before mxl862xx_setup_mdio(), and\nnothing stops it until dsa_register_switch() has returned an error to\nmxl862xx_probe(). DSA frees the dsa_port list before it returns, so a\npoll that fires once .setup or a later step of dsa_tree_setup() has\nfailed walks freed ports. On shutdown the user ports stay registered,\nand the WORK_STOPPED flag test in mxl862xx_get_stats64() is not atomic\nwith the cancel in mxl862xx_shutdown(), so a re-arm that read the flag\nbefore it was set queues the poll after cancel_delayed_work_sync() has\nreturned.\n\nArm the poll once .setup has succeeded and stop it from a .teardown op,\nwhich DSA calls on unregister and after a failed registration, in both\ncases before it frees the ports. Use disable_delayed_work_sync() there\nand in shutdown(): it drains a running poll as the cancel did and turns\nevery later attempt to queue the work into a no-op, so the re-arm\ncannot bring the poll back. remove() and the probe error path only set\nWORK_STOPPED, which crc_err_work tests before it walks the ports."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 7.8,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:L - The racing input is local: reading /proc/net/dev or RTM_GETLINK calls dsa_user_get_stats64() -\u003e mxl862xx_get_stats64(), which re-queues priv-\u003estats_work. No packet from a remote peer feeds the bug; it is a teardown-ordering error in mxl862xx_setup()/remove()/shutdown().\nAC:L - placeholder\nPR:L - Any unprivileged local user can read interface statistics on the switch\u0027s user ports, and that read is the attacker\u0027s side of the race (the schedule_delayed_work() call in mxl862xx_get_stats64()). No capability check stands in the way.\nUI:N - No victim action such as opening a file or mounting media is needed. The attacker\u0027s part is only repeated stats reads; the teardown event is covered under AC.\nS:U - The freed dsa_port objects and the devm-freed mxl862xx_priv are kernel memory, and the impact stays within the kernel\u0027s own security authority.\nC:H - mxl862xx_stats_work_fn() walks the ds-\u003eports list after dsa_switch_release_ports() has run kfree(dp). It reads dp-\u003eindex from freed memory and writes counters into priv-\u003eports[].stats. A use-after-free like this can be turned into a memory read primitive.\nI:H - On remove, a re-armed stats_work sits inside the devm-freed mxl862xx_priv. When its timer fires, the workqueue uses the work_struct and its func pointer from memory that may have been reallocated, which allows control-flow hijack. The stats poll also writes into freed memory.\nA:H - Walking freed dsa_port entries or running a work item from freed priv memory causes a kernel oops or panic. In the shutdown case, the poll keeps reaching the switch after mxl862xx_host_shutdown(), which can also crash the system during reboot."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-10-07T06:49:57.114Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
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          "url": "https://git.kernel.org/stable/c/97df811a11d4f76bc2ffe67b6bf730263f56c668"
        },
        {
          "url": "https://git.kernel.org/stable/c/9e92ad4630f5dd1838ce6bbe6b1bd2c73d34de36"
        }
      ],
      "title": "net: dsa: mxl862xx: disable the stats poll on teardown",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
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  },
  "cveMetadata": {
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    "assignerShortName": "Linux",
    "cveId": "CVE-2026-98305",
    "datePublished": "2026-10-06T08:46:02.190Z",
    "dateReserved": "2026-09-25T10:25:14.338Z",
    "dateUpdated": "2026-10-07T06:49:57.114Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
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      "date": "2026-10-09",
      "epss": "0.00129",
      "percentile": "0.02214"
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                "programFiles": [
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        "descriptions": [
          {
            "lang": "en",
            "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: dsa: mxl862xx: disable the stats poll on teardown\n\nmxl862xx_setup() arms the stats poll before mxl862xx_setup_mdio(), and\nnothing stops it until dsa_register_switch() has returned an error to\nmxl862xx_probe(). DSA frees the dsa_port list before it returns, so a\npoll that fires once .setup or a later step of dsa_tree_setup() has\nfailed walks freed ports. On shutdown the user ports stay registered,\nand the WORK_STOPPED flag test in mxl862xx_get_stats64() is not atomic\nwith the cancel in mxl862xx_shutdown(), so a re-arm that read the flag\nbefore it was set queues the poll after cancel_delayed_work_sync() has\nreturned.\n\nArm the poll once .setup has succeeded and stop it from a .teardown op,\nwhich DSA calls on unregister and after a failed registration, in both\ncases before it frees the ports. Use disable_delayed_work_sync() there\nand in shutdown(): it drains a running poll as the cancel did and turns\nevery later attempt to queue the work into a no-op, so the re-arm\ncannot bring the poll back. remove() and the probe error path only set\nWORK_STOPPED, which crc_err_work tests before it walks the ports."
          }
        ],
        "id": "CVE-2026-98305",
        "lastModified": "2026-10-07T07:17:08.357",
        "metrics": {
          "cvssMetricV31": [
            {
              "cvssData": {
                "attackComplexity": "LOW",
                "attackVector": "LOCAL",
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                "baseScore": 7.8,
                "baseSeverity": "HIGH",
                "confidentialityImpact": "HIGH",
                "integrityImpact": "HIGH",
                "privilegesRequired": "LOW",
                "scope": "UNCHANGED",
                "userInteraction": "NONE",
                "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
                "version": "3.1"
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              "impactScore": 5.9,
              "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
              "type": "Secondary"
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        "published": "2026-10-06T09:18:21.660",
        "references": [
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            "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
            "url": "https://git.kernel.org/stable/c/97df811a11d4f76bc2ffe67b6bf730263f56c668"
          },
          {
            "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
            "url": "https://git.kernel.org/stable/c/9e92ad4630f5dd1838ce6bbe6b1bd2c73d34de36"
          }
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        "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "vulnStatus": "Received"
      }
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    "suse_vex": {
      "aggregate_severity": "moderate",
      "current_release_date": "2026-10-08T16:48:06Z",
      "cve": "CVE-2026-98305",
      "id": "CVE-2026-98305",
      "initial_release_date": "2026-10-08T16:48:06Z",
      "product_status:known_not_affected": "347",
      "source": "SUSE CSAF VEX",
      "status": "interim",
      "title": "SUSE CVE CVE-2026-98305",
      "url": "https://ftp.suse.com/pub/projects/security/csaf-vex/cve-2026-98305.json",
      "version": "2"
    }
  }
}



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  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
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