{"schema":"threatline.record/2","record":{"id":"CVE-2026-98715","aliases":[],"summary":"KVM: SVM: Preserve TLB control (i.e. pending TLB flush) on failed VMRUN","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: SVM: Preserve TLB control (i.e. pending TLB flush) on failed VMRUN\n\nDon't reset the VMCB's TLB control back to \"do nothing\" on a failed VMRUN,\nas empirical testing shows that the CPU performs the requested TLB flush if\nand only if VMRUN is successful, i.e. clearing TLB control on a failed\nVMRUN effectively drops a TLB flush.\n\nExplicitly track the need to flush all ASIDs on a per-CPU basis, as the\nASID reuse condition is tied to the pCPU, not to the vCPU.  As a bonus,\nthis also obviates the need to avoid clobbering FLUSH_ALL_ASID with\nTLB_CONTROL_FLUSH_ASID, e.g. in svm_flush_tlb_asid().\n\nDeliberately don't bother saving/restoring the \"old\" tlb_ctl on failure,\nin quotes because it's not exactly the old tlb_ctl, it's the tlb_ctl from\nafter pre_svm_run(), but before updating tlb_ctl for flush_all_asids.  If\nVMRUN fails and TLB_CONTROL_FLUSH_ALL_ASID is forced, then the next\nsuccessful run of the VMCB *may* unnecessarily flush all ASIDs, which\nstrictly speaking could result in noisy neighbor issues.  However, the\nfact that new_asid() is already guest-triggerable, because of KVM's flawed\nbehavior of clearing the ASID on emulated INIT, means that a guest can\nalready trigger a flush of all ASIDs at roughly the same rate.  And once\nKVM stops clobbering the ASID on emulated INIT, *or* assigns a static ASID\nto each vCPU, this flaw goes away.","categories":["Operating systems"],"product":"Linux","vendor":"Linux","ecosystem":null,"affected_ranges":[{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-98715","source_modified_at":"2026-10-19T09:24:26.247Z","fetched_at":"2026-10-23T18:45:31.882637Z","product":"Linux","vendor":"Linux","versions":[{"version":"38e5e92fe8c02a8766459d505423b855caf9af1f","lessThan":"fd873c3d1b5240e80365f09e758e8c96b88a7cdb","status":"affected","versionType":"git"},{"version":"38e5e92fe8c02a8766459d505423b855caf9af1f","lessThan":"60d93c27859fb3ec5b5a689e24de303f166477d0","status":"affected","versionType":"git"}],"defaultStatus":"unaffected"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-98715","source_modified_at":"2026-10-19T09:24:26.247Z","fetched_at":"2026-10-23T18:45:31.882637Z","product":"Linux","vendor":"Linux","versions":[{"version":"2.6.38","status":"affected"},{"version":"0","lessThan":"2.6.38","status":"unaffected","versionType":"semver"},{"version":"7.2.10","lessThanOrEqual":"7.2.*","status":"unaffected","versionType":"semver"},{"version":"7.3","lessThanOrEqual":"*","status":"unaffected","versionType":"original_commit_for_fix"}],"defaultStatus":"affected"}],"fixed_versions":[{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-98715","source_modified_at":"2026-10-19T09:24:26.247Z","fetched_at":"2026-10-23T18:45:31.882637Z","package":{"name":"Linux","ecosystem":null},"version":"60d93c27859fb3ec5b5a689e24de303f166477d0","basis":"first unaffected version stated in the CVE record"}],"cvss":null,"severity":null,"kev":{"listed":false},"epss":{"probability":0.00189,"percentile":0.08117,"score_date":"2026-10-23"},"published_at":"2026-10-18T15:46:47.988Z","modified_at":"2026-10-19T09:24:26.247Z","provenance":[{"source":"CVE List","url":"https://www.cve.org/CVERecord?id=CVE-2026-98715","fetched_at":"2026-10-23T18:45:31.882637Z","source_modified_at":"2026-10-19T09:24:26.247Z"},{"source":"EPSS","url":"https://api.first.org/data/v1/epss?cve=CVE-2026-98715","fetched_at":"2026-10-23T18:42:43.628194Z","source_modified_at":"2026-10-23"}],"sources":["CVE List","EPSS"],"references":[{"source":"CVE List","url":"https://git.kernel.org/stable/c/fd873c3d1b5240e80365f09e758e8c96b88a7cdb"},{"source":"CVE List","url":"https://git.kernel.org/stable/c/60d93c27859fb3ec5b5a689e24de303f166477d0"}],"locations":[],"motoko_assessment":{"status":"requires_architecture_review","automatic_remediation":false},"cve_state":"PUBLISHED","classification":{"method":"product-first software-layer rules","rules_version":"2.1","matched_on":"product","confidence":"heuristic","reviewed":false},"change_timestamp":"2026-10-19T09:24:26.247Z","content_hash":"ba1bfbe9bb5adbeab79b7138892a193a3519e46c42988a6c51b26349b11ae0b6"}}