Yüksek CVSS 7.8
CVE-2026-31787: Linux Kernel: güvenlik açığı
Açıklama (NVD)
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
Özet bilgiler
- Ürün
- Linux Linux Kernel
- CVSS v3.1
- 7.8
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H - CWE
- CWE-415
- Yama
- Mevcut
Etkilenen sürümler
| Ürün | Başlangıç | Bitiş | Düzeltildi |
|---|---|---|---|
| linux-linux-kernel | 3.8 | — | 5.10.254 |
| linux-linux-kernel | 5.11 | — | 5.15.204 |
| linux-linux-kernel | 5.16 | — | 6.1.170 |
| linux-linux-kernel | 6.2 | — | 6.6.137 |
| linux-linux-kernel | 6.7 | — | 6.12.85 |
| linux-linux-kernel | 6.13 | — | 6.18.26 |
| linux-linux-kernel | 6.19 | — | 7.0.3 |
| linux-linux-kernel | 7.1 | 7.1 | — |
| linux-linux-kernel | 7.1 | 7.1 | — |