{
  "schema_version": "1.6.1",
  "id": "RPI-CVE-2026-23401",
  "modified": "2026-10-07T17:22:01Z",
  "upstream": [
    "CVE-2026-23401"
  ],
  "published": "2026-04-01T08:37:22Z",
  "summary": "KVM: x86/mmu: Drop/zap existing present SPTE even when creating an MMIO SPTE",
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: x86/mmu: Drop/zap existing present SPTE even when creating an MMIO SPTE\n\nWhen installing an emulated MMIO SPTE, do so *after* dropping/zapping the\nexisting SPTE (if it's shadow-present).  While commit a54aa15c6bda3 was\nright about it being impossible to convert a shadow-present SPTE to an\nMMIO SPTE due to a _guest_ write, it failed to account for writes to guest\nmemory that are outside the scope of KVM.\n\nE.g. if host userspace modifies a shadowed gPTE to switch from a memslot\nto emulted MMIO and then the guest hits a relevant page fault, KVM will\ninstall the MMIO SPTE without first zapping the shadow-present SPTE.\n\n  ------------[ cut here ]------------\n  is_shadow_present_pte(*sptep)\n  WARNING: arch/x86/kvm/mmu/mmu.c:484 at mark_mmio_spte+0xb2/0xc0 [kvm], CPU#0: vmx_ept_stale_r/4292\n  Modules linked in: kvm_intel kvm irqbypass\n  CPU: 0 UID: 1000 PID: 4292 Comm: vmx_ept_stale_r Not tainted 7.0.0-rc2-eafebd2d2ab0-sink-vm #319 PREEMPT\n  Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015\n  RIP: 0010:mark_mmio_spte+0xb2/0xc0 [kvm]\n  Call Trace:\n   <TASK>\n   mmu_set_spte+0x237/0x440 [kvm]\n   ept_page_fault+0x535/0x7f0 [kvm]\n   kvm_mmu_do_page_fault+0xee/0x1f0 [kvm]\n   kvm_mmu_page_fault+0x8d/0x620 [kvm]\n   vmx_handle_exit+0x18c/0x5a0 [kvm_intel]\n   kvm_arch_vcpu_ioctl_run+0xc55/0x1c20 [kvm]\n   kvm_vcpu_ioctl+0x2d5/0x980 [kvm]\n   __x64_sys_ioctl+0x8a/0xd0\n   do_syscall_64+0xb5/0x730\n   entry_SYSCALL_64_after_hwframe+0x4b/0x53\n  RIP: 0033:0x47fa3f\n   </TASK>\n  ---[ end trace 0000000000000000 ]---",
  "affected": [
    {
      "package": {
        "ecosystem": "Raspberry Pi OS:12",
        "name": "linux"
      },
      "versions": [
        "1:6.1.47-1+rpt4"
      ],
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-2712",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v6",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v7",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v7l",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v8",
            "binary_version": "1:6.1.47-1+rpt4"
          }
        ]
      },
      "database_specific": {
        "per_version": {
          "1:6.1.47-1+rpt4": {
            "linux_commit": "655fc658a15ae7a6f37103754adb39ba52a9a14e",
            "upstream_version": "6.1.47",
            "assessment": "commit ancestry (strak rule)",
            "upstream_fixed": "6.1.168",
            "compiled_filter": false
          }
        }
      }
    }
  ],
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-23401"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/20656cd1f243d3a154aac5dd1b823110b6906fe1"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/ed5909992f344a7d3f4024261e9f751d9618a27d"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/fd28c5618699180cd69619801e9ae6a5266c0a22"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/459158151a158a6703b49f3c9de0e536d8bd553f"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/695320de6eadb75aaed8be1787c4ce4c189e4c7b"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/bce7fe59d43531623f3e43779127bfb33804925d"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/aad885e774966e97b675dfe928da164214a71605"
    }
  ],
  "database_specific": {
    "source": "https://git.kernel.org/pub/scm/linux/security/vulns.git",
    "upstream_modified": "2026-05-12T04:54:46Z"
  }
}