https://vulnerability.circl.lu Contains only the most 10 recent entries. http://www.rssboard.org/rss-specification python-feedgen en Tue, 29 Sep 2026 17:17:33 +0000 https://vulnerability.circl.lu/vuln/cve-2026-31787 <p><strong>Affected:</strong> Linux</p> <p>In the Linux kernel, the following vulnerability has been resolved:</p> <p>xen/privcmd: fix double free via VMA splitting</p> <p>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.</p> <p>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)</p> <p>The surviving VMA still holds the dangling pointer. When it is later destroyed, the same sequence runs again, which leads to a double free.</p> <p>Fix this issue by adding a .may_split callback denying the VMA split.</p> <p>This is XSA-487 / CVE-2026-31787</p> <p><strong>Affected:</strong> Linux</p> <p>In the Linux kernel, the following vulnerability has been resolved:</p> <p>xen/privcmd: fix double free via VMA splitting</p> <p>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.</p> <p>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)</p> <p>The surviving VMA still holds the dangling pointer. When it is later destroyed, the same sequence runs again, which leads to a double free.</p> <p>Fix this issue by adding a .may_split callback denying the VMA split.</p> <p>This is XSA-487 / CVE-2026-31787</p> https://vulnerability.circl.lu/vuln/cve-2026-31787