KVM: arm64: Fix ID register initialization for non-protected pKVM guests
Summary
| CVE | CVE-2026-23425 |
|---|---|
| State | PUBLISHED |
| Assigner | Linux |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-04-03 14:16:28 UTC |
| Updated | 2026-04-23 21:04:11 UTC |
| Description | In the Linux kernel, the following vulnerability has been resolved: KVM: arm64: Fix ID register initialization for non-protected pKVM guests In protected mode, the hypervisor maintains a separate instance of the `kvm` structure for each VM. For non-protected VMs, this structure is initialized from the host's `kvm` state. Currently, `pkvm_init_features_from_host()` copies the `KVM_ARCH_FLAG_ID_REGS_INITIALIZED` flag from the host without the underlying `id_regs` data being initialized. This results in the hypervisor seeing the flag as set while the ID registers remain zeroed. Consequently, `kvm_has_feat()` checks at EL2 fail (return 0) for non-protected VMs. This breaks logic that relies on feature detection, such as `ctxt_has_tcrx()` for TCR2_EL1 support. As a result, certain system registers (e.g., TCR2_EL1, PIR_EL1, POR_EL1) are not saved/restored during the world switch, which could lead to state corruption. Fix this by explicitly copying the ID registers from the host `kvm` to the hypervisor `kvm` for non-protected VMs during initialization, since we trust the host with its non-protected guests' features. Also ensure `KVM_ARCH_FLAG_ID_REGS_INITIALIZED` is cleared initially in `pkvm_init_features_from_host` so that `vm_copy_id_regs` can properly initialize them and set the flag once done. |
Risk And Classification
Primary CVSS: v3.1 5.5 MEDIUM from [email protected]
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
EPSS: 0.000170000 probability, percentile 0.039750000 (date 2026-04-07)
Problem Types: NVD-CWE-noinfo
CVSS v3.1 Breakdown
Attack Vector
LocalAttack Complexity
LowPrivileges Required
LowUser Interaction
NoneScope
UnchangedConfidentiality
NoneIntegrity
NoneAvailability
HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
NVD Known Affected Configurations (CPE 2.3)
| Type | Vendor | Product | Version | Update | Edition | Language |
|---|---|---|---|---|---|---|
| Operating System | Linux | Linux Kernel | All | All | All | All |
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Linux | Linux | affected 41d6028e28bd474298ff10409c292ec46cf43a90 bce3847f7c51b86332bf2e554c9e80ca3820f16c git | Not specified |
| CNA | Linux | Linux | affected 41d6028e28bd474298ff10409c292ec46cf43a90 858620655c1fbff05997e162fc7d83a3293d5142 git | Not specified |
| CNA | Linux | Linux | affected 41d6028e28bd474298ff10409c292ec46cf43a90 7e7c2cf0024d89443a7af52e09e47b1fe634ab17 git | Not specified |
| CNA | Linux | Linux | affected 6.14 | Not specified |
| CNA | Linux | Linux | unaffected 6.14 semver | Not specified |
| CNA | Linux | Linux | unaffected 6.18.17 6.18.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.19.7 6.19.* semver | Not specified |
| CNA | Linux | Linux | unaffected 7.0 * original_commit_for_fix | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| git.kernel.org/stable/c/bce3847f7c51b86332bf2e554c9e80ca3820f16c | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | Patch |
| git.kernel.org/stable/c/858620655c1fbff05997e162fc7d83a3293d5142 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | Patch |
| git.kernel.org/stable/c/7e7c2cf0024d89443a7af52e09e47b1fe634ab17 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | Patch |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
No vendor comments have been submitted for this CVE.
There are currently no legacy QID mappings associated with this CVE.