CVE-2026-98305 (GCVE-0-2026-98305)
Vulnerability from cvelistv5
Published
2026-10-06 08:46
Modified
2026-10-19 09:17
Severity ?
VLAI Severity ?
EPSS score ?
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.
References
Impacted products
{
"containers": {
"cna": {
"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",
"versions": [
{
"lessThan": "97df811a11d4f76bc2ffe67b6bf730263f56c668",
"status": "affected",
"version": "a21d33a5265f0b31d935a8b9b2b6faefb5185911",
"versionType": "git"
},
{
"lessThan": "9e92ad4630f5dd1838ce6bbe6b1bd2c73d34de36",
"status": "affected",
"version": "a21d33a5265f0b31d935a8b9b2b6faefb5185911",
"versionType": "git"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"drivers/net/dsa/mxl862xx/mxl862xx.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "7.1"
},
{
"lessThan": "7.1",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "7.2.*",
"status": "unaffected",
"version": "7.2.8",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.3",
"versionType": "original_commit_for_fix"
}
]
}
],
"cpeApplicability": [
{
"nodes": [
{
"cpeMatch": [
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "7.2.8",
"versionStartIncluding": "7.1",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "7.3",
"versionStartIncluding": "7.1",
"vulnerable": true
}
],
"negate": false,
"operator": "OR"
}
]
}
],
"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": "2026-10-19T09:17:16.045Z",
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"shortName": "Linux"
},
"references": [
{
"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"
}
}
},
"cveMetadata": {
"assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"assignerShortName": "Linux",
"cveId": "CVE-2026-98305",
"datePublished": "2026-10-06T08:46:02.190Z",
"dateReserved": "2026-09-25T10:25:14.338Z",
"dateUpdated": "2026-10-19T09:17:16.045Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
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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.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- 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.
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