CVE-2026-46317 Details
Description
In the Linux kernel, the following vulnerability has been resolved: KVM: arm64: Reassign nested_mmus array behind mmu_lock kvm->arch.nested_mmus[] is walked under kvm->mmu_lock, including from the MMU notifier path (kvm_unmap_gfn_range() -> kvm_nested_s2_unmap()), which can run at any time. kvm_vcpu_init_nested() reallocates the array and frees the old buffer while holding only kvm->arch.config_lock, so such a walker can reference the freed array. Allocate the new array outside of mmu_lock, as the allocation can sleep. Under the lock, copy the existing entries, fix up the back pointers and reassign the array. Free the old buffer after dropping the lock, as kvfree() can sleep as well.
A vulnerability exists in the Linux kernel's KVM (Kernel-based Virtual Machine) module for arm64 architecture, specifically in the management of nested memory management unit (MMU) structures. The issue arises because the nested MMU array is accessed under the MMU lock, including during MMU notifier operations, which can occur unpredictably. When the KVM virtual CPU initialization function reallocates the nested MMU array, it frees the old buffer while only holding a different lock, potentially allowing other processes to reference the now-freed memory. This vulnerability could lead to use-after-free errors. The problem has been addressed by changing the allocation process to occur outside of the MMU lock, allowing the reallocation to be safely managed without risking memory corruption.
Users can upgrade to the latest version of the Linux kernel where this vulnerability has been fixed. Instructions for downloading the patched version are available on the official Linux kernel website.
Metrics
CVSS 4.0 Severity and Vector Strings:
No CVSS 4.0 data is available for this CVE.
CVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
No SSVC data is available for this CVE.
References to Advisories, Solutions, and Tools
By selecting these links, you will be leaving this site. These are references gathered from the official CVE record and are not endorsed by Volerion.
| URL | Source(s) | Tag(s) |
|---|---|---|
| https://git.kernel.org/stable/c/4424dbcb06d68e34e51c019a5781a7dc00731971 | kernel.org | Patch |
| https://git.kernel.org/stable/c/70543358fa08e0f7cebc3447c3b70fe97ad7aaa8 | kernel.org | Patch |
| https://git.kernel.org/stable/c/918450ad6010df6ecd2efde12a1409e011da22d6 | kernel.org | Patch |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| NVD-CWE-noinfo | Insufficient Information to Classify Weakness | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| linux linux kernel | >= 6.11, < 6.18.35 >= 6.19, < 7.0.12 7.1 rc1 7.1 rc2 7.1 rc3 7.1 rc4 7.1 rc5 7.1 rc6 |
CPE
Remediation
| |
Change History
5 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Jul 23, 2026 | CVE Translated | [email protected] |
| Jul 8, 2026 | Initial Analysis | [email protected] |
| Jun 17, 2026 | CVE Modified | kernel.org |
| Jun 14, 2026 | CVE Modified | kernel.org |
| Jun 9, 2026 | New CVE Received | kernel.org |