{"api_version":"1","generated_at":"2026-10-21T18:43:00+00:00","cve":"CVE-2026-98464","urls":{"html":"https://cve.report/CVE-2026-98464","api":"https://cve.report/api/cve/CVE-2026-98464.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-98464","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-98464"},"summary":{"title":"RISC-V: KVM: Synchronize hrtimer callback during teardown","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nRISC-V: KVM: Synchronize hrtimer callback during teardown\n\nThe non-Sstc hrtimer callback clears next_set before its final uses of\nthe enclosing vCPU.  If teardown observes next_set as false while the\ncallback is still running, kvm_riscv_vcpu_timer_cancel() skips\nhrtimer_cancel() and kvm_destroy_vcpus() can free the vCPU before the\ncallback enters kvm_riscv_vcpu_set_interrupt().\n\nA guest can arm the timer with SBI TIME and request shutdown with SBI\nlegacy shutdown or SRST.  A VMM that honors KVM_EXIT_SYSTEM_EVENT and\ndestroys the VM supplies the teardown side of the race; no post-launch\nhost ioctl is needed to arm or request teardown.\n\nOn upstream master 62cc90241548, generic KASAN reported:\n\n  BUG: KASAN: slab-use-after-free in do_raw_spin_lock\n  Write of size 4 at addr ff60000005e58898\n\n  kvm_riscv_vcpu_set_interrupt\n  kvm_riscv_vcpu_hrtimer_expired\n  __hrtimer_run_queues\n  hrtimer_interrupt\n\nThe object was allocated by KVM_CREATE_VCPU and freed concurrently by:\n\n  kvm_destroy_vcpus\n  kvm_arch_destroy_vm\n  kvm_destroy_vm\n  __fput\n\nFor deterministic validation, I added mdelay(1000) immediately after\nthe existing next_set = false assignment.  This only widens the\nexisting post-clear callback window.  A no-delay trace build naturally\nreached the callback-after-teardown-start/before-deinit ordering in 12\nof 200 runs, but 1,500 stock-kernel stress iterations did not produce a\nKASAN report, so natural reproduction is timing-sensitive.\n\nAlways invoke hrtimer_cancel() for an initialized timer.  Preserve the\nexisting -EINVAL result when the timer is no longer set, but only after\nsynchronizing with a running callback.\n\nWith this patch, hrtimer_cancel() blocked for the full widened callback\nwindow before vCPU destruction.  KASAN reported no error in 100\nfixed-and-widened runs or 200 fix-only timing-sweep runs.","state":"PUBLISHED","assigner":"Linux","published_at":"2026-10-18 16:16:56","updated_at":"2026-10-19 10:18:56"},"problem_types":[],"metrics":[],"references":[{"url":"https://git.kernel.org/stable/c/aaad136d56d91252517272b68cd533e5714698d5","name":"https://git.kernel.org/stable/c/aaad136d56d91252517272b68cd533e5714698d5","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/3cc6184bd5920c9685d87f4e260568feba08650d","name":"https://git.kernel.org/stable/c/3cc6184bd5920c9685d87f4e260568feba08650d","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/9bdbae64ae0dab93041ebc57ec4e93def793fc2d","name":"https://git.kernel.org/stable/c/9bdbae64ae0dab93041ebc57ec4e93def793fc2d","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/ea91f05a55b807ead3166546a2c75f4185ca645f","name":"https://git.kernel.org/stable/c/ea91f05a55b807ead3166546a2c75f4185ca645f","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/2af03b606aadaaeb386658ef798c79bdcdef87c1","name":"https://git.kernel.org/stable/c/2af03b606aadaaeb386658ef798c79bdcdef87c1","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/e66aced74f0122380603c9910a71d77618b28f0e","name":"https://git.kernel.org/stable/c/e66aced74f0122380603c9910a71d77618b28f0e","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-98464","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-98464","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 3a9f66cb25e18a3eeca36c08d9f823a35b3ddc22 9bdbae64ae0dab93041ebc57ec4e93def793fc2d git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 3a9f66cb25e18a3eeca36c08d9f823a35b3ddc22 2af03b606aadaaeb386658ef798c79bdcdef87c1 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 3a9f66cb25e18a3eeca36c08d9f823a35b3ddc22 e66aced74f0122380603c9910a71d77618b28f0e git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 3a9f66cb25e18a3eeca36c08d9f823a35b3ddc22 ea91f05a55b807ead3166546a2c75f4185ca645f git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 3a9f66cb25e18a3eeca36c08d9f823a35b3ddc22 3cc6184bd5920c9685d87f4e260568feba08650d git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 3a9f66cb25e18a3eeca36c08d9f823a35b3ddc22 aaad136d56d91252517272b68cd533e5714698d5 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 5.16","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 5.16 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.1.189 6.1.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.6.158 6.6.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.12.112 6.12.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.18.55 6.18.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.2.9 7.2.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.3 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":null,"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["arch/riscv/kvm/vcpu_timer.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"9bdbae64ae0dab93041ebc57ec4e93def793fc2d","status":"affected","version":"3a9f66cb25e18a3eeca36c08d9f823a35b3ddc22","versionType":"git"},{"lessThan":"2af03b606aadaaeb386658ef798c79bdcdef87c1","status":"affected","version":"3a9f66cb25e18a3eeca36c08d9f823a35b3ddc22","versionType":"git"},{"lessThan":"e66aced74f0122380603c9910a71d77618b28f0e","status":"affected","version":"3a9f66cb25e18a3eeca36c08d9f823a35b3ddc22","versionType":"git"},{"lessThan":"ea91f05a55b807ead3166546a2c75f4185ca645f","status":"affected","version":"3a9f66cb25e18a3eeca36c08d9f823a35b3ddc22","versionType":"git"},{"lessThan":"3cc6184bd5920c9685d87f4e260568feba08650d","status":"affected","version":"3a9f66cb25e18a3eeca36c08d9f823a35b3ddc22","versionType":"git"},{"lessThan":"aaad136d56d91252517272b68cd533e5714698d5","status":"affected","version":"3a9f66cb25e18a3eeca36c08d9f823a35b3ddc22","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["arch/riscv/kvm/vcpu_timer.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"5.16"},{"lessThan":"5.16","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"6.1.*","status":"unaffected","version":"6.1.189","versionType":"semver"},{"lessThanOrEqual":"6.6.*","status":"unaffected","version":"6.6.158","versionType":"semver"},{"lessThanOrEqual":"6.12.*","status":"unaffected","version":"6.12.112","versionType":"semver"},{"lessThanOrEqual":"6.18.*","status":"unaffected","version":"6.18.55","versionType":"semver"},{"lessThanOrEqual":"7.2.*","status":"unaffected","version":"7.2.9","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.3","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.1.189","versionStartIncluding":"5.16","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.6.158","versionStartIncluding":"5.16","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.12.112","versionStartIncluding":"5.16","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.55","versionStartIncluding":"5.16","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.2.9","versionStartIncluding":"5.16","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.3","versionStartIncluding":"5.16","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nRISC-V: KVM: Synchronize hrtimer callback during teardown\n\nThe non-Sstc hrtimer callback clears next_set before its final uses of\nthe enclosing vCPU.  If teardown observes next_set as false while the\ncallback is still running, kvm_riscv_vcpu_timer_cancel() skips\nhrtimer_cancel() and kvm_destroy_vcpus() can free the vCPU before the\ncallback enters kvm_riscv_vcpu_set_interrupt().\n\nA guest can arm the timer with SBI TIME and request shutdown with SBI\nlegacy shutdown or SRST.  A VMM that honors KVM_EXIT_SYSTEM_EVENT and\ndestroys the VM supplies the teardown side of the race; no post-launch\nhost ioctl is needed to arm or request teardown.\n\nOn upstream master 62cc90241548, generic KASAN reported:\n\n  BUG: KASAN: slab-use-after-free in do_raw_spin_lock\n  Write of size 4 at addr ff60000005e58898\n\n  kvm_riscv_vcpu_set_interrupt\n  kvm_riscv_vcpu_hrtimer_expired\n  __hrtimer_run_queues\n  hrtimer_interrupt\n\nThe object was allocated by KVM_CREATE_VCPU and freed concurrently by:\n\n  kvm_destroy_vcpus\n  kvm_arch_destroy_vm\n  kvm_destroy_vm\n  __fput\n\nFor deterministic validation, I added mdelay(1000) immediately after\nthe existing next_set = false assignment.  This only widens the\nexisting post-clear callback window.  A no-delay trace build naturally\nreached the callback-after-teardown-start/before-deinit ordering in 12\nof 200 runs, but 1,500 stock-kernel stress iterations did not produce a\nKASAN report, so natural reproduction is timing-sensitive.\n\nAlways invoke hrtimer_cancel() for an initialized timer.  Preserve the\nexisting -EINVAL result when the timer is no longer set, but only after\nsynchronizing with a running callback.\n\nWith this patch, hrtimer_cancel() blocked for the full widened callback\nwindow before vCPU destruction.  KASAN reported no error in 100\nfixed-and-widened runs or 200 fix-only timing-sweep runs."}],"providerMetadata":{"dateUpdated":"2026-10-19T09:20:02.501Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/9bdbae64ae0dab93041ebc57ec4e93def793fc2d"},{"url":"https://git.kernel.org/stable/c/2af03b606aadaaeb386658ef798c79bdcdef87c1"},{"url":"https://git.kernel.org/stable/c/e66aced74f0122380603c9910a71d77618b28f0e"},{"url":"https://git.kernel.org/stable/c/ea91f05a55b807ead3166546a2c75f4185ca645f"},{"url":"https://git.kernel.org/stable/c/3cc6184bd5920c9685d87f4e260568feba08650d"},{"url":"https://git.kernel.org/stable/c/aaad136d56d91252517272b68cd533e5714698d5"}],"title":"RISC-V: KVM: Synchronize hrtimer callback during teardown","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-98464","datePublished":"2026-10-18T15:15:16.624Z","dateReserved":"2026-09-25T10:25:14.350Z","dateUpdated":"2026-10-19T09:20:02.501Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-10-18 16:16:56","lastModifiedDate":"2026-10-19 10:18:56","problem_types":[],"metrics":[],"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"98464","Ordinal":"1","Title":"RISC-V: KVM: Synchronize hrtimer callback during teardown","CVE":"CVE-2026-98464","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"98464","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\nRISC-V: KVM: Synchronize hrtimer callback during teardown\n\nThe non-Sstc hrtimer callback clears next_set before its final uses of\nthe enclosing vCPU.  If teardown observes next_set as false while the\ncallback is still running, kvm_riscv_vcpu_timer_cancel() skips\nhrtimer_cancel() and kvm_destroy_vcpus() can free the vCPU before the\ncallback enters kvm_riscv_vcpu_set_interrupt().\n\nA guest can arm the timer with SBI TIME and request shutdown with SBI\nlegacy shutdown or SRST.  A VMM that honors KVM_EXIT_SYSTEM_EVENT and\ndestroys the VM supplies the teardown side of the race; no post-launch\nhost ioctl is needed to arm or request teardown.\n\nOn upstream master 62cc90241548, generic KASAN reported:\n\n  BUG: KASAN: slab-use-after-free in do_raw_spin_lock\n  Write of size 4 at addr ff60000005e58898\n\n  kvm_riscv_vcpu_set_interrupt\n  kvm_riscv_vcpu_hrtimer_expired\n  __hrtimer_run_queues\n  hrtimer_interrupt\n\nThe object was allocated by KVM_CREATE_VCPU and freed concurrently by:\n\n  kvm_destroy_vcpus\n  kvm_arch_destroy_vm\n  kvm_destroy_vm\n  __fput\n\nFor deterministic validation, I added mdelay(1000) immediately after\nthe existing next_set = false assignment.  This only widens the\nexisting post-clear callback window.  A no-delay trace build naturally\nreached the callback-after-teardown-start/before-deinit ordering in 12\nof 200 runs, but 1,500 stock-kernel stress iterations did not produce a\nKASAN report, so natural reproduction is timing-sensitive.\n\nAlways invoke hrtimer_cancel() for an initialized timer.  Preserve the\nexisting -EINVAL result when the timer is no longer set, but only after\nsynchronizing with a running callback.\n\nWith this patch, hrtimer_cancel() blocked for the full widened callback\nwindow before vCPU destruction.  KASAN reported no error in 100\nfixed-and-widened runs or 200 fix-only timing-sweep runs.","Type":"Description","Title":"RISC-V: KVM: Synchronize hrtimer callback during teardown"}]}}}