xen/privcmd: fix double free via VMA splitting (Linux Linux)
At a glance
- Source
- NVD
- EPSS
- EPSS 0.18 % · percentile 8 ()
- State
- PUBLISHED
- Published
- Updated
- Assigner
- Linux
- NVD status
- Analyzed
Description
In the Linux kernel, the following vulnerability has been resolved: xen/privcmd: fix double free via VMA splitting privcmd_vm_ops defines .close (privcmd_close), but neither .may_split nor .open. When userspace does a partial munmap() on a privcmd mapping, the kernel splits the VMA via __split_vma(). Since may_split is NULL, the split is allowed. vm_area_dup() copies vm_private_data (a pages array allocated in alloc_empty_pages()) into the new VMA without any fixup, because there is no .open callback. Both VMAs now point to the same pages array. When the unmapped portion is closed, privcmd_close() calls: - xen_unmap_domain_gfn_range() - xen_free_unpopulated_pages() - kvfree(pages) The surviving VMA still holds the dangling pointer. When it is later destroyed, the same sequence runs again, which leads to a double free. Fix this issue by adding a .may_split callback denying the VMA split. This is XSA-487 / CVE-2026-31787
Weaknesses (CWE)
- CWE-415 — Double Free
References
- https://git.kernel.org/stable/c/dbf862ce9f009128ab86b234d91413a3e450beb4
- https://git.kernel.org/stable/c/2b985d3a024b9e8c24e21671b34e855569763808
- https://git.kernel.org/stable/c/1576ff3869cbd3620717195f971c85b7d7fd62b5
- https://git.kernel.org/stable/c/402d84ad9e89bd4cbfd07ca8598532b7021daf95
- https://git.kernel.org/stable/c/2894a351fe2ea8684919d36df3188b9a35e3926f
- https://git.kernel.org/stable/c/446ee446d9ae66f36e95c3c90bbcc4e56b94cde0
- https://git.kernel.org/stable/c/71bf829800758a6e3889096e4754ef47ba7fc850
- https://git.kernel.org/stable/c/24daca4fc07f3ff8cd0e3f629cd982187f48436a
- http://www.openwall.com/lists/oss-security/2026/04/28/14
- http://xenbits.xen.org/xsa/advisory-487.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 | NVD · nvd@nist.gov (Primary) |
European references
- ENISA EUVD · EUVD-2026-26365
- GCVE · GCVE-0-2026-31787
CERT-FR advisories
- CERTFR-2026-AVI-1028 — Multiples vulnérabilités dans le noyau Linux de Red Hat · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0986 — Multiples vulnérabilités dans les produits IBM · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0983 — Multiples vulnérabilités dans le noyau Linux de Red Hat · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0955 — Multiples vulnérabilités dans le noyau Linux de Red Hat · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0808 — Multiples vulnérabilités dans le noyau Linux de Red Hat · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0781 — Multiples vulnérabilités dans le noyau Linux de Red Hat · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0697 — Multiples vulnérabilités dans le noyau Linux de SUSE · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0696 — Multiples vulnérabilités dans le noyau Linux de Debian LTS · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0664 — Multiples vulnérabilités dans le noyau Linux de SUSE · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0548 — Multiples vulnérabilités dans le noyau Linux de Debian · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0547 — Multiples vulnérabilités dans le noyau Linux de Debian LTS · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0509 — Multiples vulnérabilités dans Xen · cert.ssi.gouv.fr
Affected configurations (NVD CPE)
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*≥ 3.8 < 5.10.254cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*≥ 5.11 < 5.15.204cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*≥ 5.16 < 6.1.170cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*≥ 6.2 < 6.6.137cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*≥ 6.7 < 6.12.85cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*≥ 6.13 < 6.18.26cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*≥ 6.19 < 7.0.3cpe:2.3:o:linux:linux_kernel:7.1:rc1:*:*:*:*:*:*cpe:2.3:o:linux:linux_kernel:7.1:rc2:*:*:*:*:*:*
Affected products
| Product | Versions |
|---|---|
| Linux · Linux | affected d71f513985c22f1050295d1a7e4327cf9fb060da < dbf862ce9f009128ab86b234d91413a3e450beb4 ; affected d71f513985c22f1050295d1a7e4327cf9fb060da < 2b985d3a024b9e8c24e21671b34e855569763808 ; affected d71f513985c22f1050295d1a7e4327cf9fb060da < 1576ff3869cbd3620717195f971c85b7d7fd62b5 ; affected d71f513985c22f1050295d1a7e4327cf9fb060da < 402d84ad9e89bd4cbfd07ca8598532b7021daf95 ; affected d71f513985c22f1050295d1a7e4327cf9fb060da < 2894a351fe2ea8684919d36df3188b9a35e3926f ; affected d71f513985c22f1050295d1a7e4327cf9fb060da < 446ee446d9ae66f36e95c3c90bbcc4e56b94cde0 |
| Linux · Linux | affected 3.8 ; unaffected 0 < 3.8 ; unaffected 5.10.254 ≤ 5.10.* ; unaffected 5.15.204 ≤ 5.15.* ; unaffected 6.1.170 ≤ 6.1.* ; unaffected 6.6.137 ≤ 6.6.* |
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 |