CVE-2026-98262
Full vulnerability record from the local CVENow database.
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.
Severity
Not scored
CVSS score
Not available
Vulnerability status
Received
Source identifier
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Published
2026-10-06 09:18:15.347000
Last modified
2026-10-19 10:18:27.390000
View original CVE JSON
{
"id": "CVE-2026-98262",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"published": "2026-10-06T09:18:15.347",
"lastModified": "2026-10-19T10:18:27.390",
"vulnStatus": "Received",
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "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 '0'\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."
}
],
"affected": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"affectedData": [
{
"vendor": "Linux",
"product": "Linux",
"defaultStatus": "unaffected",
"programFiles": [
"drivers/ata/libahci.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"versions": [
{
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"status": "affected"
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"versions": [
{
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},
{
"version": "0",
"lessThan": "2.6.22",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "5.10.271",
"lessThanOrEqual": "5.10.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "5.15.222",
"lessThanOrEqual": "5.15.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.1.189",
"lessThanOrEqual": "6.1.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.6.158",
"lessThanOrEqual": "6.6.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.12.112",
"lessThanOrEqual": "6.12.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.18.54",
"lessThanOrEqual": "6.18.*",
"versionType": "semver",
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},
{
"version": "7.2.8",
"lessThanOrEqual": "7.2.*",
"versionType": "semver",
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},
{
"version": "7.3",
"lessThanOrEqual": "*",
"versionType": "original_commit_for_fix",
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}
]
}
]
}
],
"metrics": {},
"references": [
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}