UBUNTU-CVE-2026-72169: Low severity ubuntu/linux-hwe-edge vulnerability
In the Linux kernel, the following vulnerability has been resolved: kho: make sure scratch size is always aligned by CMAMINALIGNMENTBYTES When using scratchscale, the scratch sizes are rounded up to CMAMINALIGNMENTBYTES since they will be released as MIGRATECMA. This is not done when using fixed scratch sizes via command line. This can result in user specifying a size which is not aligned, and thus kernel releasing a pageblock that is only partially scratch. Do the rounding up for both cases in scratchsizeupdate().
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
ubuntu/linux-aws-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1014.14~24.04.1 - Upgrade
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ubuntu/linux-azure-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1017.17~24.04.1 - Upgrade
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ubuntu/linux-azure-fde-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1016.16~24.04.1 - Upgrade
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ubuntu/linux-gcp-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1014.14~24.04.1 - Upgrade
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ubuntu/linux-hwe-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-38.38~24.04.4 - Upgrade
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ubuntu/linux-nvidia-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1024.25~24.04.1 - Upgrade
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ubuntu/linux-oracle-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1013.13~24.04.1 - Upgrade
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ubuntu/linux-riscv-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-38.38.1~24.04.1 - Upgrade
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ubuntu/linuxto a version that resolves this vulnerability.Fixed in 7.0.0-38.38 - Upgrade
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ubuntu/linux-awsto a version that resolves this vulnerability.Fixed in 7.0.0-1014.14 - Upgrade
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ubuntu/linux-azureto a version that resolves this vulnerability.Fixed in 7.0.0-1017.17 - Upgrade
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ubuntu/linux-azure-fdeto a version that resolves this vulnerability.Fixed in 7.0.0-1016.16 - Upgrade
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ubuntu/linux-gcpto a version that resolves this vulnerability.Fixed in 7.0.0-1014.14 - Upgrade
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ubuntu/linux-gketo a version that resolves this vulnerability.Fixed in 7.0.0-1008.9 - Upgrade
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ubuntu/linux-ibmto a version that resolves this vulnerability.Fixed in 7.0.0-1015.15 - Upgrade
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ubuntu/linux-nvidia-bosto a version that resolves this vulnerability.Fixed in 7.0.0-2022.23 - Upgrade
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ubuntu/linux-oem-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1015.15 - Upgrade
Upgrade
ubuntu/linux-oracleto a version that resolves this vulnerability.Fixed in 7.0.0-1013.13 - Upgrade
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ubuntu/linux-realtimeto a version that resolves this vulnerability.Fixed in 7.0.0-38.38.1 - Upgrade
Upgrade
ubuntu/linux-riscvto a version that resolves this vulnerability.Fixed in 7.0.0-38.38.1 - Compensating control
Update scratch_size_update() to round up scratch sizes to CMA_MIN_ALIGNMENT_BYTES in both the scratch_scale and fixed scratch-size cases.
Event History
Frequently Asked Questions
Which systems are exposed to this issue?
Exposure requires use of the kernel's KHO scratch-memory configuration with a fixed scratch size supplied through the command line. The affected Ubuntu kernel packages listed are linux-riscv, linux-realtime, linux-hwe-edge, linux-azure, linux-gcp, linux-azure-fde, linux-gke, and linux-aws-5.0.
What configuration causes the unsafe behavior?
A fixed command-line scratch size that is not aligned to CMA_MIN_ALIGNMENT_BYTES can cause a pageblock that is only partially scratch to be released as MIGRATE_CMA. Scratch sizes configured through scratch_scale are already rounded up to this alignment.
What is the relevant mitigation if an update cannot be applied immediately?
Avoid specifying an unaligned fixed KHO scratch size on the kernel command line. Use a size aligned to CMA_MIN_ALIGNMENT_BYTES, or use scratch_scale, which rounds the size up to that alignment.