Vulnerabilidad · Publicado 19/07/2026 · Actualizado 01/08/2026
In the Linux kernel, the following vulnerability has been resolved:
arm64: tlb: Flush walk cache when unsharing PMD tables
When huge_pmd_unshare() is called to unshare a PMD table, the
tlb_unshare_pmd_ptdesc() function sets tlb->unshared_tables=true
but the aarch64 tlb_flush() only checked tlb->freed_tables to
determine whether to use TLBF_NONE (vae1is, invalidates walk
cache) or TLBF_NOWALKCACH…
In the Linux kernel, the following vulnerability has been resolved: arm64: tlb: Flush walk cache when unsharing PMD tables When huge_pmd_unshare() is called to unshare a PMD table, the tlb_unshare_pmd_ptdesc() function sets tlb->unshared_tables=true but the aarch64 tlb_flush() only checked tlb->freed_tables to determine whether to use TLBF_NONE (vae1is, invalidates walk cache) or TLBF_NOWALKCACHE (vale1is, leaf-only). This caused the stale PMD page table entry to remain in the walk cache after unshare, potentially leading to incorrect page table walks. Fix by including unshared_tables in the check, so that when unsharing tables, TLBF_NONE is used and the walk cache is properly invalidated. Here is the detailed distinction between vae1is and vale1is: | Instruction Combination | Actual Invalidation Scope | | ------------------------ | --------------------------------------------------| | `VAE1IS` + TTL=`0` | All entries at all levels (full invalidation) | | `VAE1IS` + TTL=`2` (L2) | Non-leaf at Level 0/1 + leaf at Level 2 | | `VALE1IS` + TTL=`0` | Leaf entries at all levels (non-leaf not cleared) | | `VALE1IS` + TTL=`2` (L2) | Leaf entry at Level 2 only |
Score: 7.8/10 — Severidad: HIGH — Estado NIST: Awaiting Analysis
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Publicado en NIST NVD.