CVE-2026-80551: s390/vfio_ccw: Ensure first IDAW remains constant
In the Linux kernel, the following vulnerability has been resolved:
s390/vfioccw: Ensure first IDAW remains constant
The first IDAW in a list does not need to be on a 2K/4K boundary like all others, and so is read separately to accurately calculate the size of the buffer needed to read the full IDAL.
Verify that the address found in the first IDAW is unchanged between reads, to ensure a consistent set of IDAWs being worked with.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 6.6.157.1-1 - Upgrade
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debian/linuxto a version that resolves this vulnerability.Fixed in 6.12.105-1 - Upgrade
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debian/linuxto a version that resolves this vulnerability.Fixed in 7.1.10-1 - Upgrade
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debian/linux-6.12to a version that resolves this vulnerability.Fixed in 6.12.107-1~deb12u1 - Upgrade
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linux/Kernelto a version that resolves this vulnerability.Fixed in 6.1.191 - Upgrade
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linux/Kernelto a version that resolves this vulnerability.Fixed in 6.6.154 - Upgrade
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linux/Kernelto a version that resolves this vulnerability.Fixed in 6.12.105 - Upgrade
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linux/Kernelto a version that resolves this vulnerability.Fixed in 6.18.46 - Upgrade
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linux/Kernelto a version that resolves this vulnerability.Fixed in 7.1.10 - Upgrade
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debian/linuxto a version that resolves this vulnerability.Fixed in 6.12.107-1Fixed in 6.12.115-2Fixed in 7.2.12-1Fixed in 7.2.15-1 - Upgrade
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debian/linux-6.12to a version that resolves this vulnerability.Fixed in 6.12.113-1~deb12u1 - Upgrade
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ubuntu/linux-hwe-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-42.42~24.04.1 - Upgrade
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ubuntu/linux-nvidia-tegrato a version that resolves this vulnerability.Fixed in 6.8.0-1036.39 - Upgrade
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ubuntu/linux-riscv-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-42.42.1~24.04.1 - Upgrade
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ubuntu/linuxto a version that resolves this vulnerability.Fixed in 7.0.0-42.42 - Upgrade
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ubuntu/linux-awsto a version that resolves this vulnerability.Fixed in 7.0.0-1016.17 - Upgrade
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ubuntu/linux-gcpto a version that resolves this vulnerability.Fixed in 7.0.0-1016.18 - Upgrade
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ubuntu/linux-ibmto a version that resolves this vulnerability.Fixed in 7.0.0-1017.17 - Upgrade
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ubuntu/linux-oem-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1017.17 - Upgrade
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ubuntu/linux-oracleto a version that resolves this vulnerability.Fixed in 7.0.0-1015.16 - Upgrade
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ubuntu/linux-riscvto a version that resolves this vulnerability.Fixed in 7.0.0-42.42.1 - Compensating control
Verify that the address found in the first IDAW remains unchanged between reads, ensuring a consistent set of IDAWs is used when calculating and reading the full IDAL.
Event History
Frequently Asked Questions
Which systems are exposed to this issue?
The affected component is the Linux kernel s390 vfio_ccw code path. Systems not using that architecture and component are not indicated by the provided information as exposed.
What condition triggers the vulnerable behavior?
The issue arises when the address in the first IDAW changes between the separate reads used to calculate the IDAL buffer size and read the full IDAL. The provided information does not state what attacker access or workload conditions could cause that change.
What does the fix do?
The fix verifies that the address found in the first IDAW remains unchanged between reads. This ensures the kernel works with a consistent set of IDAWs when calculating and reading the IDAL.