ata: libahci: clear PxCLBU and PxFBU for AHCI_HFLAG_32BIT_ONLY (Linux Linux)
At a glance
- Source
- NVD
- EPSS
- EPSS 0.18 % · percentile 7 ()
- State
- PUBLISHED
- Published
- Updated
- Assigner
- Linux
- NVD status
- Received
Description
In 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.
References
- https://git.kernel.org/stable/c/0191c9ff23ef1678dbfb5ad253a2dee92feb5d71
- https://git.kernel.org/stable/c/8f510f68208a1f673d7c7234a687be4671490e9c
- https://git.kernel.org/stable/c/4719424bb7cb9f20b73986bcb72dd528f0e5c6eb
- https://git.kernel.org/stable/c/a5a8b4737f68bbac8aa0685af0c8921e6003c22b
- https://git.kernel.org/stable/c/b28a17d4a9bb0aa38b48681c3927b012ba40eabe
- https://git.kernel.org/stable/c/b691a3e244278362e552439d6d3ee5a5d3703488
- https://git.kernel.org/stable/c/7912ad8fb5233bb8cfe21d50df639c7f4854ff9d
- https://git.kernel.org/stable/c/82e47533221d4746947b74d2e79a478c36c6433a
European references
- ENISA EUVD · EUVD-2026-93190
- GCVE · GCVE-0-2026-98262
CERT-FR advisories
- CERTFR-2026-AVI-1385 — Multiples vulnérabilités dans les produits VMware · cert.ssi.gouv.fr
- CERTFR-2026-AVI-1375 — Multiples vulnérabilités dans le noyau Linux de Debian LTS · cert.ssi.gouv.fr
- CERTFR-2026-AVI-1374 — Multiples vulnérabilités dans le noyau Linux de Debian · cert.ssi.gouv.fr
Affected products
| Product | Versions |
|---|---|
| Linux · Linux | affected c7a42156d99bcea7f8173ba7a6034bbaa2ecb77c < 0191c9ff23ef1678dbfb5ad253a2dee92feb5d71 ; affected c7a42156d99bcea7f8173ba7a6034bbaa2ecb77c < 8f510f68208a1f673d7c7234a687be4671490e9c ; affected c7a42156d99bcea7f8173ba7a6034bbaa2ecb77c < 4719424bb7cb9f20b73986bcb72dd528f0e5c6eb ; affected c7a42156d99bcea7f8173ba7a6034bbaa2ecb77c < a5a8b4737f68bbac8aa0685af0c8921e6003c22b ; affected c7a42156d99bcea7f8173ba7a6034bbaa2ecb77c < b28a17d4a9bb0aa38b48681c3927b012ba40eabe ; affected c7a42156d99bcea7f8173ba7a6034bbaa2ecb77c < b691a3e244278362e552439d6d3ee5a5d3703488 |
| Linux · Linux | affected 2.6.22 ; unaffected 0 < 2.6.22 ; unaffected 5.10.271 ≤ 5.10.* ; unaffected 5.15.222 ≤ 5.15.* ; unaffected 6.1.189 ≤ 6.1.* ; unaffected 6.6.158 ≤ 6.6.* |
Sources
| Source | Licence |
|---|---|
| CVE List (CVEProject cvelistV5) | CVE Program Terms of Use |
| EPSS (FIRST.org) | FIRST — attribution requested |
| ENISA EUVD | ENISA — reproduction authorised, source acknowledged |
| CERT-FR (ANSSI) | Licence Ouverte / Etalab 2.0 |
| NVD (NIST) via fkie-cad/nvd-json-data-feeds | Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD |