{
  "affected": [
    {
      "ecosystem_specific": {
        "urgency": "not yet assigned"
      },
      "package": {
        "ecosystem": "Debian:12",
        "name": "linux"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "6.1.187-1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "ecosystem_specific": {
        "urgency": "not yet assigned"
      },
      "package": {
        "ecosystem": "Debian:13",
        "name": "linux"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "6.12.101-1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "ecosystem_specific": {
        "urgency": "not yet assigned"
      },
      "package": {
        "ecosystem": "Debian:14",
        "name": "linux"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "7.1.6-1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "ecosystem_specific": {
        "urgency": "not yet assigned"
      },
      "package": {
        "ecosystem": "Debian:12",
        "name": "linux-6.12"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "6.12.101-1~deb12u1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "details": "In the Linux kernel, the following vulnerability has been resolved:  KVM: SVM: Bump asid_generation on CPU online to avoid ASID collision after hotplug  If a vCPU stays scheduled out (or blocked) while the last pCPU it ran on goes through a hotplug cycle (online-\u003eoffline-\u003eonline), and the vCPU then resumes execution on the same pCPU, then it is possible for it to run with an ASID that has now been assigned to a different vCPU, resulting in stale TLB translations being used.  svm_enable_virtualization_cpu() resets asid_generation to 1 and sets next_asid to max_asid + 1 on every CPU online event, including hotplug cycles.  Because next_asid starts beyond the pool boundary, the first call to new_asid() after an online event always wraps the pool, incrementing asid_generation to 2 and assigning ASIDs starting from min_asid.  Consider two vCPUs from different VMs, vCPU-A pinned to CPU-X holding asid_generation=2 and ASID=N from before the hotplug event:    1. CPU-X goes offline and back online: asid_generation resets to 1,      next_asid = max_asid + 1.    2. One or more vCPUs migrate to CPU-X and call new_asid(), wrapping      the pool and consuming ASIDs starting from min_asid.  Eventually      vCPU-B from a different VM is assigned asid_generation=2, ASID=N      — the same ASID that vCPU-A held before the hotplug.    3. vCPU-A enters pre_svm_run() on CPU-X: current_vmcb-\u003ecpu is      unchanged so the migration branch is skipped.  Its saved      asid_generation=2 matches sd-\u003easid_generation=2, so the generation      check silently passes and vCPU-A continues running with ASID=N —      the same ASID just freshly assigned to vCPU-B.  Both vCPUs from different VMs now run on CPU-X with the same ASID, causing them to share NPT TLB entries and producing stale translations.  The collision manifests as a KVM internal error (Suberror: 1, emulation failure).  The NPT page fault reports a faulting GPA far outside the VM's physical memory range — a sign of stale TLB translations being used.  KVM falls back to instruction emulation, which fails on FPU/XSave instructions (XRSTOR, STMXCSR) that the emulator does not implement.  Fix this by incrementing asid_generation instead of resetting it to 1 in svm_enable_virtualization_cpu().  On module load, asid_generation starts at 0 (memset) and the increment produces 1, identical to the old behaviour.  On subsequent hotplug cycles the generation advances beyond any value a vCPU previously observed on this CPU, so the generation check in pre_svm_run() reliably forces new_asid() on every vCPU after every hotplug cycle.",
  "id": "DEBIAN-CVE-2026-68093",
  "modified": "2026-09-14T16:47:50.311968102Z",
  "published": "2026-08-10T13:19:53.303Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://security-tracker.debian.org/tracker/CVE-2026-68093"
    }
  ],
  "upstream": [
    "CVE-2026-68093"
  ]
}