CVE-2026-43253
Full vulnerability record from the local CVENow database.
Description
In the Linux kernel, the following vulnerability has been resolved: iommu/amd: move wait_on_sem() out of spinlock With iommu.strict=1, the existing completion wait path can cause soft lockups under stressed environment, as wait_on_sem() busy-waits under the spinlock with interrupts disabled. Move the completion wait in iommu_completion_wait() out of the spinlock. wait_on_sem() only polls the hardware-updated cmd_sem and does not require iommu->lock, so holding the lock during the busy wait unnecessarily increases contention and extends the time with interrupts disabled.
Severity
HIGH
CVSS score
7.5
(v3.1)
Vulnerability status
Modified
Source identifier
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Published
2026-05-06 12:16:46.033000
Last modified
2026-10-30 13:18:49.557000
View original CVE JSON
{
"id": "CVE-2026-43253",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"published": "2026-05-06T12:16:46.033",
"lastModified": "2026-10-30T13:18:49.557",
"vulnStatus": "Modified",
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\niommu/amd: move wait_on_sem() out of spinlock\n\nWith iommu.strict=1, the existing completion wait path can cause soft\nlockups under stressed environment, as wait_on_sem() busy-waits under the\nspinlock with interrupts disabled.\n\nMove the completion wait in iommu_completion_wait() out of the spinlock.\nwait_on_sem() only polls the hardware-updated cmd_sem and does not require\niommu->lock, so holding the lock during the busy wait unnecessarily\nincreases contention and extends the time with interrupts disabled."
}
],
"affected": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"affectedData": [
{
"vendor": "Linux",
"product": "Linux",
"defaultStatus": "unaffected",
"programFiles": [
"drivers/iommu/amd/iommu.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"versions": [
{
"version": "4bf5beef578e46393f11eb69dda7d17a065e05ff",
"lessThan": "69d9339c02eddfc2a345be7220651068a3684383",
"versionType": "git",
"status": "affected"
},
{
"version": "4bf5beef578e46393f11eb69dda7d17a065e05ff",
"lessThan": "f2f65b28d802a667119147444ec2ae33eebf9a58",
"versionType": "git",
"status": "affected"
},
{
"version": "4bf5beef578e46393f11eb69dda7d17a065e05ff",
"lessThan": "715c263119fd1b918a9fcbd8a36ea5b604a46324",
"versionType": "git",
"status": "affected"
},
{
"version": "4bf5beef578e46393f11eb69dda7d17a065e05ff",
"lessThan": "e15768e68820142077bbca402d8e902f64ade1b0",
"versionType": "git",
"status": "affected"
},
{
"version": "4bf5beef578e46393f11eb69dda7d17a065e05ff",
"lessThan": "496269d12072ecb219826485bdbec70c92a8eef5",
"versionType": "git",
"status": "affected"
},
{
"version": "4bf5beef578e46393f11eb69dda7d17a065e05ff",
"lessThan": "d2a0cac10597068567d336e85fa3cbdbe8ca62bf",
"versionType": "git",
"status": "affected"
}
]
},
{
"vendor": "Linux",
"product": "Linux",
"defaultStatus": "affected",
"programFiles": [
"drivers/iommu/amd/iommu.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"versions": [
{
"version": "4.9",
"status": "affected"
},
{
"version": "0",
"lessThan": "4.9",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.1.191",
"lessThanOrEqual": "6.1.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.6.128",
"lessThanOrEqual": "6.6.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.12.75",
"lessThanOrEqual": "6.12.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.18.16",
"lessThanOrEqual": "6.18.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.19.6",
"lessThanOrEqual": "6.19.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "7.0",
"lessThanOrEqual": "*",
"versionType": "original_commit_for_fix",
"status": "unaffected"
}
]
}
]
}
],
"metrics": {
"cvssMetricV31": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"type": "Secondary",
"cvssData": {
"version": "3.1",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"baseScore": 7.5,
"baseSeverity": "HIGH",
"attackVector": "NETWORK",
"attackComplexity": "LOW",
"privilegesRequired": "NONE",
"userInteraction": "NONE",
"scope": "UNCHANGED",
"confidentialityImpact": "NONE",
"integrityImpact": "NONE",
"availabilityImpact": "HIGH"
},
"exploitabilityScore": 3.9,
"impactScore": 3.6
}
],
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"timestamp": "2026-10-16T15:16:08.841212Z",
"id": "CVE-2026-43253",
"options": [
{
"exploitation": "none"
},
{
"automatable": "yes"
},
{
"technicalImpact": "partial"
}
],
"role": "CISA Coordinator",
"version": "2.0.3"
}
}
]
},
"weaknesses": [
{
"source": "[email protected]",
"type": "Primary",
"description": [
{
"lang": "en",
"value": "CWE-667"
}
]
},
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"type": "Secondary",
"description": [
{
"lang": "en",
"value": "CWE-833"
}
]
}
],
"configurations": [
{
"nodes": [
{
"operator": "OR",
"negate": false,
"cpeMatch": [
{
"vulnerable": true,
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionStartIncluding": "4.9",
"versionEndExcluding": "6.6.128",
"matchCriteriaId": "FC8C6130-AEEE-4496-B72F-C7A386E011DC"
},
{
"vulnerable": true,
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionStartIncluding": "6.7",
"versionEndExcluding": "6.12.75",
"matchCriteriaId": "BCE16369-98ED-41CF-8995-DFDC10B288D2"
},
{
"vulnerable": true,
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionStartIncluding": "6.13",
"versionEndExcluding": "6.18.16",
"matchCriteriaId": "B4B8CDA9-BADF-4CF5-8B3B-702DE8EEA40B"
},
{
"vulnerable": true,
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionStartIncluding": "6.19",
"versionEndExcluding": "6.19.6",
"matchCriteriaId": "373EEEDA-FAA1-4FB4-B6ED-DB4DD99DBE67"
}
]
}
]
}
],
"references": [
{
"url": "https://git.kernel.org/stable/c/496269d12072ecb219826485bdbec70c92a8eef5",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"tags": [
"Patch"
]
},
{
"url": "https://git.kernel.org/stable/c/69d9339c02eddfc2a345be7220651068a3684383",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/715c263119fd1b918a9fcbd8a36ea5b604a46324",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"tags": [
"Patch"
]
},
{
"url": "https://git.kernel.org/stable/c/d2a0cac10597068567d336e85fa3cbdbe8ca62bf",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"tags": [
"Patch"
]
},
{
"url": "https://git.kernel.org/stable/c/e15768e68820142077bbca402d8e902f64ade1b0",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"tags": [
"Patch"
]
},
{
"url": "https://git.kernel.org/stable/c/f2f65b28d802a667119147444ec2ae33eebf9a58",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"tags": [
"Patch"
]
}
]
}