KVM: Explicitly verify target vCPU is online in kvm_get_vcpu() (Linux Linux)
At a glance
- Source
- NVD
- EPSS
- EPSS 0.22 % · percentile 13 ()
- State
- PUBLISHED
- Published
- Updated
- Assigner
- Linux
- NVD status
- Modified
Description
In the Linux kernel, the following vulnerability has been resolved: KVM: Explicitly verify target vCPU is online in kvm_get_vcpu() Explicitly verify the target vCPU is fully online _prior_ to clamping the index in kvm_get_vcpu(). If the index is "bad", the nospec clamping will generate '0', i.e. KVM will return vCPU0 instead of NULL. In practice, the bug is unlikely to cause problems, as it will only come into play if userspace or the guest is buggy or misbehaving, e.g. KVM may send interrupts to vCPU0 instead of dropping them on the floor. However, returning vCPU0 when it shouldn't exist per online_vcpus is problematic now that KVM uses an xarray for the vCPUs array, as KVM needs to insert into the xarray before publishing the vCPU to userspace (see commit c5b077549136 ("KVM: Convert the kvm->vcpus array to a xarray")), i.e. before vCPU creation is guaranteed to succeed. As a result, incorrectly providing access to vCPU0 will trigger a use-after-free if vCPU0 is dereferenced and kvm_vm_ioctl_create_vcpu() bails out of vCPU creation due to an error and frees vCPU0. Commit afb2acb2e3a3 ("KVM: Fix vcpu_array[0] races") papered over that issue, but in doing so introduced an unsolvable teardown conundrum. Preventing accesses to vCPU0 before it's fully online will allow reverting commit afb2acb2e3a3, without re-introducing the vcpu_array[0] UAF race.
Weaknesses (CWE)
- CWE-416 — Use After Free
References
- https://git.kernel.org/stable/c/5cce2ed69b00e022b5cdf0c49c82986abd2941a8
- https://git.kernel.org/stable/c/09d50ccf0b2d739db4a485b08afe7520a4402a63
- https://git.kernel.org/stable/c/7c4899239d0f70f88ac42665b3da51678d122480
- https://git.kernel.org/stable/c/d817e510662fd1c9797952408d94806f97a5fffd
- https://git.kernel.org/stable/c/125da53b3c0c9d7f58353aea0076e9efd6498ba7
- https://git.kernel.org/stable/c/f2f805ada63b536bc192458a7098388286568ad4
- https://git.kernel.org/stable/c/ca8da90ed1432ff3d000de4f1e2275d4e7d21b96
- https://git.kernel.org/stable/c/1e7381f3617d14b3c11da80ff5f8a93ab14cfc46
- https://lists.debian.org/debian-lts-announce/2025/05/msg00030.html
- https://lists.debian.org/debian-lts-announce/2025/03/msg00028.html
- https://cert-portal.siemens.com/productcert/html/ssa-784472.html
Scores
| Version | Score | Vector | Scored by |
|---|---|---|---|
| CVSS 3.1 | HIGH 7.8 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H | Linux |
| CVSS 3.1 | HIGH 7.8 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H | CISA-ADP |
| CVSS 3.1 | HIGH 7.8 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H | NVD · 416baaa9-dc9f-4396-8d5f-8c081fb06d67 (Secondary) |
| CVSS 3.1 | HIGH 7.8 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H | NVD · 134c704f-9b21-4f2e-91b3-4a467353bcc0 (Secondary) |
European references
- ENISA EUVD · EUVD-2024-54016
- GCVE · GCVE-0-2024-58083
CERT-FR advisories
- CERTFR-2026-AVI-1298 — Multiples vulnérabilités dans les produits Siemens · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0106 — Multiples vulnérabilités dans le noyau Linux d'Ubuntu · cert.ssi.gouv.fr
- CERTFR-2025-AVI-1135 — Multiples vulnérabilités dans le noyau Linux d'Ubuntu · cert.ssi.gouv.fr
- CERTFR-2025-AVI-1075 — Multiples vulnérabilités dans le noyau Linux d'Ubuntu · cert.ssi.gouv.fr
- CERTFR-2025-AVI-0969 — Multiples vulnérabilités dans les produits VMware · cert.ssi.gouv.fr
- CERTFR-2025-AVI-0758 — Multiples vulnérabilités dans le noyau Linux d'Ubuntu · cert.ssi.gouv.fr
- CERTFR-2025-AVI-0625 — Multiples vulnérabilités dans le noyau Linux d'Ubuntu · cert.ssi.gouv.fr
- CERTFR-2025-AVI-0605 — Multiples vulnérabilités dans le noyau Linux d'Ubuntu · cert.ssi.gouv.fr
- CERTFR-2025-AVI-0559 — Multiples vulnérabilités dans le noyau Linux d'Ubuntu · cert.ssi.gouv.fr
- CERTFR-2025-AVI-0529 — Multiples vulnérabilités dans le noyau Linux de SUSE · cert.ssi.gouv.fr
- CERTFR-2025-AVI-0509 — Multiples vulnérabilités dans le noyau Linux de SUSE · cert.ssi.gouv.fr
- CERTFR-2025-AVI-0463 — Multiples vulnérabilités dans le noyau Linux de Debian LTS · cert.ssi.gouv.fr
- CERTFR-2025-AVI-0336 — Multiples vulnérabilités dans le noyau Linux de SUSE · cert.ssi.gouv.fr
- CERTFR-2025-AVI-0307 — Multiples vulnérabilités dans le noyau Linux de SUSE · cert.ssi.gouv.fr
- CERTFR-2025-AVI-0277 — Multiples vulnérabilités dans le noyau Linux de Debian LTS · cert.ssi.gouv.fr
Affected configurations (NVD CPE)
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*≥ 4.14.120 < 4.15cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*≥ 4.19.44 < 4.20cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*≥ 5.0.17 < 5.4.291cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*≥ 5.5 < 5.10.235cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*≥ 5.11 < 5.15.179cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*≥ 5.16 < 6.1.129cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*≥ 6.2 < 6.6.78cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*≥ 6.7 < 6.12.14cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*≥ 6.13 < 6.13.3
Affected products
| Product | Versions |
|---|---|
| Linux · Linux | affected 1d487e9bf8ba66a7174c56a0029c54b1eca8f99c < 5cce2ed69b00e022b5cdf0c49c82986abd2941a8 ; affected 1d487e9bf8ba66a7174c56a0029c54b1eca8f99c < 09d50ccf0b2d739db4a485b08afe7520a4402a63 ; affected 1d487e9bf8ba66a7174c56a0029c54b1eca8f99c < 7c4899239d0f70f88ac42665b3da51678d122480 ; affected 1d487e9bf8ba66a7174c56a0029c54b1eca8f99c < d817e510662fd1c9797952408d94806f97a5fffd ; affected 1d487e9bf8ba66a7174c56a0029c54b1eca8f99c < 125da53b3c0c9d7f58353aea0076e9efd6498ba7 ; affected 1d487e9bf8ba66a7174c56a0029c54b1eca8f99c < f2f805ada63b536bc192458a7098388286568ad4 |
| Linux · Linux | affected 5.1 ; unaffected 0 < 5.1 ; unaffected 5.4.291 ≤ 5.4.* ; unaffected 5.10.235 ≤ 5.10.* ; unaffected 5.15.179 ≤ 5.15.* ; unaffected 6.1.129 ≤ 6.1.* |
Sources
| Source | Licence |
|---|---|
| CVE List (CVEProject cvelistV5) | CVE Program Terms of Use |
| EPSS (FIRST.org) | FIRST — attribution requested |
| ENISA EUVD | ENISA — reproduction authorised, source acknowledged |
| CERT-FR (ANSSI) | Licence Ouverte / Etalab 2.0 |
| NVD (NIST) via fkie-cad/nvd-json-data-feeds | Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD |