CVE-2026-72213: mm/hugetlb: fix hugetlb cgroup rsvd charge/uncharge mismatch
In the Linux kernel, the following vulnerability has been resolved:
mm/hugetlb: fix hugetlb cgroup rsvd charge/uncharge mismatch
In allochugetlbfolio(), a single hcg pointer is used for both the rsvd and non-rsvd hugetlb cgroup charges. When mapchg is set, hugetlbcgroupchargecgrouprsvd() stores the charged cgroup in hcg, but the immediately following hugetlbcgroupchargecgroup() overwrites hcg with the non-rsvd cgroup pointer.
As a result, hugetlbcgroupcommitchargersvd() stores the wrong (non-rsvd) cgroup pointer into the folio's rsvd slot.
When the folio is later freed, freehugefolio() unconditionally calls both hugetlbcgroupunchargefolio() and hugetlbcgroupunchargefoliorsvd(). The rsvd uncharge reads back the wrong cgroup from the folio and decrements a counter that was never charged for that cgroup, causing a pagecounter underflow:
pagecounter underflow: -512 nrpages=512 WARNING: mm/pagecounter.c:61 at pagecountercancel
Fix this by introducing a separate hcgrsvd pointer exclusively for the rsvd charge path, keeping the rsvd and non-rsvd charges fully independent through their charge, commit, and error uncharge paths.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
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ubuntu/linuxto a version that resolves this vulnerability.Fixed in 6.8.0-147.147 - Upgrade
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ubuntu/linux-awsto a version that resolves this vulnerability.Fixed in 6.8.0-1067.70 - Upgrade
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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-azureto a version that resolves this vulnerability.Fixed in 6.8.0-1071.79 - 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-fdeto a version that resolves this vulnerability.Fixed in 6.8.0-1069.76 - 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-gcpto a version that resolves this vulnerability.Fixed in 6.8.0-1071.79 - 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-gketo a version that resolves this vulnerability.Fixed in 6.8.0-1066.74 - Upgrade
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ubuntu/linux-gkeopto a version that resolves this vulnerability.Fixed in 6.8.0-1052.56 - 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-ibmto a version that resolves this vulnerability.Fixed in 6.8.0-1067.68 - Upgrade
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ubuntu/linux-lowlatencyto a version that resolves this vulnerability.Fixed in 6.8.0-147.147.1 - 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-oracleto a version that resolves this vulnerability.Fixed in 6.8.0-1064.67 - 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/linux-bluefieldto a version that resolves this vulnerability.Fixed in 6.8.0-1033.38 - Upgrade
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ubuntu/linux-realtimeto a version that resolves this vulnerability.Fixed in 6.8.1-1062.63 - Upgrade
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ubuntu/linux-aws-fipsto a version that resolves this vulnerability.Fixed in 6.8.0-1067.70+fips1 - Upgrade
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ubuntu/linux-azure-fipsto a version that resolves this vulnerability.Fixed in 6.8.0-1071.79+fips1 - Upgrade
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ubuntu/linux-fipsto a version that resolves this vulnerability.Fixed in 6.8.0-147.147+fips1 - Upgrade
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ubuntu/linux-gcp-fipsto a version that resolves this vulnerability.Fixed in 6.8.0-1071.79+fips1 - 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-oem-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1015.15 - Upgrade
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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
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ubuntu/linux-riscvto a version that resolves this vulnerability.Fixed in 7.0.0-38.38.1 - Upgrade
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debian/linuxto a version that resolves this vulnerability.Fixed in 6.12.101-1 - Upgrade
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debian/linuxto a version that resolves this vulnerability.Fixed in 7.1.5-1 - Upgrade
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debian/linux-6.12to a version that resolves this vulnerability.Fixed in 6.12.101-1~deb12u1 - Upgrade
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debian/linuxto a version that resolves this vulnerability.Fixed in 6.12.107-1Fixed in 6.12.113-1Fixed in 7.2.12-1Fixed in 7.2.14-1 - 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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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 6.6.160 - Upgrade
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linux/Kernelto a version that resolves this vulnerability.Fixed in 6.12.101 - Upgrade
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linux/Kernelto a version that resolves this vulnerability.Fixed in 6.18.40 - Upgrade
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linux/Kernelto a version that resolves this vulnerability.Fixed in 7.1.5
Event History
Frequently Asked Questions
What is the severity of CVE-2026-72213?
The severity of CVE-2026-72213 is rated as 34.
How do I fix CVE-2026-72213?
To fix CVE-2026-72213, update your Linux kernel to the patched version that resolves the hugetlb cgroup charge mismatch.
What systems are affected by CVE-2026-72213?
CVE-2026-72213 affects systems running certain versions of the Linux kernel that utilize hugetlb memory management.
Is CVE-2026-72213 a local or remote vulnerability?
CVE-2026-72213 is considered a local vulnerability, as it requires access to the affected system to exploit.
What impact could CVE-2026-72213 have on my system?
CVE-2026-72213 could lead to inconsistencies in memory charges for hugetlb cgroups, potentially affecting resource management.