GHSA-599J-5783-GX62
Vulnerability from github – Published: 2026-10-06 09:31 – Updated: 2026-10-06 09:31In the Linux kernel, the following vulnerability has been resolved:
ata: libahci: clear PxCLBU and PxFBU for AHCI_HFLAG_32BIT_ONLY
A user reported that commit 105c42566a55 ("ata: ahci: force 32-bit DMA for JMicron JMB582/JMB585") made the JMicron JMB585 unusable on his board.
The failure is seen as soon as the ahci driver is probed, and booting with iommu=off does not solve the problem.
Looking at the AHCI specification, PxCLBU and PxFBU are both read only '0' for HBAs that do not support 64-bit addressing.
For HBAs that do support 64-bit addressing, the registers are read write, with a reset value that is Implementation Specific.
When using the AHCI_HFLAG_32BIT_ONLY flag, the HBA does support 64-bit addressing, and a 32-bit DMA mask is set by simply clearing HOST_CAP_64. Thus, in this case, we need to explicitly clear the registers to 0.
{
"affected": [],
"aliases": [
"CVE-2026-98262"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-10-06T09:18:15Z",
"severity": null
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nata: libahci: clear PxCLBU and PxFBU for AHCI_HFLAG_32BIT_ONLY\n\nA user reported that commit 105c42566a55 (\"ata: ahci: force 32-bit DMA for\nJMicron JMB582/JMB585\") made the JMicron JMB585 unusable on his board.\n\nThe failure is seen as soon as the ahci driver is probed, and booting with\niommu=off does not solve the problem.\n\nLooking at the AHCI specification, PxCLBU and PxFBU are both read only \u00270\u0027\nfor HBAs that do not support 64-bit addressing.\n\nFor HBAs that do support 64-bit addressing, the registers are read write,\nwith a reset value that is Implementation Specific.\n\nWhen using the AHCI_HFLAG_32BIT_ONLY flag, the HBA does support 64-bit\naddressing, and a 32-bit DMA mask is set by simply clearing HOST_CAP_64.\nThus, in this case, we need to explicitly clear the registers to 0.",
"id": "GHSA-599j-5783-gx62",
"modified": "2026-10-06T09:31:32Z",
"published": "2026-10-06T09:31:32Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-98262"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/0191c9ff23ef1678dbfb5ad253a2dee92feb5d71"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/4719424bb7cb9f20b73986bcb72dd528f0e5c6eb"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/7912ad8fb5233bb8cfe21d50df639c7f4854ff9d"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/82e47533221d4746947b74d2e79a478c36c6433a"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/8f510f68208a1f673d7c7234a687be4671490e9c"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/a5a8b4737f68bbac8aa0685af0c8921e6003c22b"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/b28a17d4a9bb0aa38b48681c3927b012ba40eabe"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/b691a3e244278362e552439d6d3ee5a5d3703488"
}
],
"schema_version": "1.4.0",
"severity": []
}
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
Related by attack behaviour
Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.