CVE-2025-37996: KVM: arm64: Fix uninitialized memcache pointer in user_mem_abort()

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-05-29 · updated 2026-07-30
Weakness: CWE-908

Description

In the Linux kernel, the following vulnerability has been resolved: KVM: arm64: Fix uninitialized memcache pointer in user_mem_abort() Commit fce886a60207 ("KVM: arm64: Plumb the pKVM MMU in KVM") made the initialization of the local memcache variable in user_mem_abort() conditional, leaving a codepath where it is used uninitialized via kvm_pgtable_stage2_map(). This can fail on any path that requires a stage-2 allocation without transition via a permission fault or dirty logging. Fix this by making sure that memcache is always valid.

Affected products

Linux kernel: from 6.14 before 6.14.7; 6.15-rc1, 6.15-rc2, 6.15-rc3, 6.15-rc4, 6.15-rc5 — fixed in 6.14.7

How to fix

Upgrade to a fixed version: Linux kernel 6.14.7. Check the vendor advisory for mitigations.

References

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