ata: libahci: clear PxCLBU and PxFBU for AHCI_HFLAG_32BIT_ONLY
Summary
| CVE | CVE-2026-98262 |
|---|---|
| State | PUBLISHED |
| Assigner | Linux |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-10-06 09:18:15 UTC |
| Updated | 2026-10-06 09:18:15 UTC |
| 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. |
Risk And Classification
EPSS: 0.001840000 probability, percentile 0.073050000 (date 2026-10-06)
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Linux | Linux | affected c7a42156d99bcea7f8173ba7a6034bbaa2ecb77c 0191c9ff23ef1678dbfb5ad253a2dee92feb5d71 git | Not specified |
| CNA | Linux | Linux | affected c7a42156d99bcea7f8173ba7a6034bbaa2ecb77c 8f510f68208a1f673d7c7234a687be4671490e9c git | Not specified |
| CNA | Linux | Linux | affected c7a42156d99bcea7f8173ba7a6034bbaa2ecb77c 4719424bb7cb9f20b73986bcb72dd528f0e5c6eb git | Not specified |
| CNA | Linux | Linux | affected c7a42156d99bcea7f8173ba7a6034bbaa2ecb77c a5a8b4737f68bbac8aa0685af0c8921e6003c22b git | Not specified |
| CNA | Linux | Linux | affected c7a42156d99bcea7f8173ba7a6034bbaa2ecb77c b28a17d4a9bb0aa38b48681c3927b012ba40eabe git | Not specified |
| CNA | Linux | Linux | affected c7a42156d99bcea7f8173ba7a6034bbaa2ecb77c b691a3e244278362e552439d6d3ee5a5d3703488 git | Not specified |
| CNA | Linux | Linux | affected c7a42156d99bcea7f8173ba7a6034bbaa2ecb77c 7912ad8fb5233bb8cfe21d50df639c7f4854ff9d git | Not specified |
| CNA | Linux | Linux | affected c7a42156d99bcea7f8173ba7a6034bbaa2ecb77c 82e47533221d4746947b74d2e79a478c36c6433a git | Not specified |
| CNA | Linux | Linux | affected 2.6.22 | Not specified |
| CNA | Linux | Linux | unaffected 2.6.22 semver | Not specified |
| CNA | Linux | Linux | unaffected 5.10.271 5.10.* semver | Not specified |
| CNA | Linux | Linux | unaffected 5.15.222 5.15.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.1.189 6.1.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.6.158 6.6.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.12.112 6.12.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.18.54 6.18.* semver | Not specified |
| CNA | Linux | Linux | unaffected 7.2.8 7.2.* semver | Not specified |
| CNA | Linux | Linux | unaffected 7.3-rc4 * original_commit_for_fix | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| git.kernel.org/stable/c/4719424bb7cb9f20b73986bcb72dd528f0e5c6eb | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/0191c9ff23ef1678dbfb5ad253a2dee92feb5d71 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/82e47533221d4746947b74d2e79a478c36c6433a | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/b28a17d4a9bb0aa38b48681c3927b012ba40eabe | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/a5a8b4737f68bbac8aa0685af0c8921e6003c22b | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/b691a3e244278362e552439d6d3ee5a5d3703488 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/8f510f68208a1f673d7c7234a687be4671490e9c | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/7912ad8fb5233bb8cfe21d50df639c7f4854ff9d | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
No vendor comments have been submitted for this CVE.
There are currently no legacy QID mappings associated with this CVE.