CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:HIn the Linux kernel, the following vulnerability has been resolved: userfaultfd: prevent registration of special VMAs Vova Tokarev says: userfaultfd allows registration on shadow stack VMAs. With userfaultfd access, you can register on the shadow stack, discard a page ... and inject a page with chosen return addresses via UFFDIO_COPY. Update vma_can_userfault() to reject VM_SHADOW_STACK. While on it, also reject VM_SPECIAL so that if a driver would implement vm_uffd_ops, it wouldn't be possible to register special VMAs with userfaultfd. Since VM_SPECIAL includes VM_DONTEXPAND which is set but hugetlb, exclude hugetlb VMAs from the check for VM_SPECIAL. A flaw was found in the Linux kernel's userfaultfd mechanism. A local attacker with userfaultfd access could register on shadow stack Virtual Memory Areas (VMAs). By discarding a page and injecting a page with chosen return addresses, an attacker could achieve arbitrary code execution. This vulnerability arises from the improper handling of special VMAs, including shadow stacks, allowing for manipulation of memory regions.
Multiple vulnerabilities have been discovered in the Linux kernel of Debian. These vulnerabilities allow for privilege escalation, data compromise, and denial of service. The affected Debian versions are prior to 6.12.10…