{"id":"CVE-2026-98465","state":"PUBLISHED","title":"RISC-V: KVM: Serialize IMSIC attributes with vCPU migration","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nRISC-V: KVM: Serialize IMSIC attributes with vCPU migration\n\nKVM device ioctls are not serialized against KVM_RUN. As a result,\nkvm_riscv_aia_imsic_rw_attr() can snapshot the physical CPU and HGEI of\nan IMSIC VS-file before a concurrent vCPU migration releases it.\n\nThe HGEI can then be allocated to another vCPU before imsic_vsfile_rw()\nuses the stale tuple. A GET or SET attribute may consequently access the\nnew owner's interrupt file.\n\nSerialize the entire IMSIC attribute operation with the target vCPU\nmutex. This prevents the VS-file from being migrated and recycled until\nthe attribute access completes. Acquire the mutex killably so that the\ndevice ioctl remains interruptible while waiting for KVM_RUN to finish.","publishedAt":"2026-10-18T15:15:17.498Z","updatedAt":"2026-10-24T14:08:57.467Z","severity":{"score":7,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:L/I:L/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"db8b7e97d6137a28b2bfc07e591d54da268f0c36","status":"affected","lessThan":"6c2bcf6b173d4afed883cceea9d47f2c5194161d","versionType":"git"},{"version":"db8b7e97d6137a28b2bfc07e591d54da268f0c36","status":"affected","lessThan":"a29c5d2dd2ef9a8617a9a6d5585696d5f149cd98","versionType":"git"},{"version":"db8b7e97d6137a28b2bfc07e591d54da268f0c36","status":"affected","lessThan":"c525772c304c971b0d3a1f2898dedbae653efe90","versionType":"git"},{"version":"db8b7e97d6137a28b2bfc07e591d54da268f0c36","status":"affected","lessThan":"71acbea44e78665ea90e3c310fca6bbdcc0252db","versionType":"git"},{"version":"db8b7e97d6137a28b2bfc07e591d54da268f0c36","status":"affected","lessThan":"8ae12ccaec6ec74945d8c1ef39f2c1b8df779abc","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["arch/riscv/kvm/aia_imsic.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.5","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.5","versionType":"semver"},{"version":"6.6.160","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.112","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.55","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.9","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["arch/riscv/kvm/aia_imsic.c"]}],"references":["https://git.kernel.org/stable/c/6c2bcf6b173d4afed883cceea9d47f2c5194161d","https://git.kernel.org/stable/c/a29c5d2dd2ef9a8617a9a6d5585696d5f149cd98","https://git.kernel.org/stable/c/c525772c304c971b0d3a1f2898dedbae653efe90","https://git.kernel.org/stable/c/71acbea44e78665ea90e3c310fca6bbdcc0252db","https://git.kernel.org/stable/c/8ae12ccaec6ec74945d8c1ef39f2c1b8df779abc"],"weaknesses":[],"ingestedAt":"2026-10-29T20:13:43.249Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/98xxx/CVE-2026-98465.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-98465","state":"PUBLISHED","datePublished":"2026-10-18T15:15:17.498Z","dateUpdated":"2026-10-24T14:08:57.467Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-09-25T10:25:14.350Z"},"containers":{"cna":{"title":"RISC-V: KVM: Serialize IMSIC attributes with vCPU migration","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nRISC-V: KVM: Serialize IMSIC attributes with vCPU migration\n\nKVM device ioctls are not serialized against KVM_RUN. As a result,\nkvm_riscv_aia_imsic_rw_attr() can snapshot the physical CPU and HGEI of\nan IMSIC VS-file before a concurrent vCPU migration releases it.\n\nThe HGEI can then be allocated to another vCPU before imsic_vsfile_rw()\nuses the stale tuple. A GET or SET attribute may consequently access the\nnew owner's interrupt file.\n\nSerialize the entire IMSIC attribute operation with the target vCPU\nmutex. This prevents the VS-file from being migrated and recycled until\nthe attribute access completes. Acquire the mutex killably so that the\ndevice ioctl remains interruptible while waiting for KVM_RUN to finish."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"db8b7e97d6137a28b2bfc07e591d54da268f0c36","status":"affected","lessThan":"6c2bcf6b173d4afed883cceea9d47f2c5194161d","versionType":"git"},{"version":"db8b7e97d6137a28b2bfc07e591d54da268f0c36","status":"affected","lessThan":"a29c5d2dd2ef9a8617a9a6d5585696d5f149cd98","versionType":"git"},{"version":"db8b7e97d6137a28b2bfc07e591d54da268f0c36","status":"affected","lessThan":"c525772c304c971b0d3a1f2898dedbae653efe90","versionType":"git"},{"version":"db8b7e97d6137a28b2bfc07e591d54da268f0c36","status":"affected","lessThan":"71acbea44e78665ea90e3c310fca6bbdcc0252db","versionType":"git"},{"version":"db8b7e97d6137a28b2bfc07e591d54da268f0c36","status":"affected","lessThan":"8ae12ccaec6ec74945d8c1ef39f2c1b8df779abc","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["arch/riscv/kvm/aia_imsic.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.5","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.5","versionType":"semver"},{"version":"6.6.160","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.112","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.55","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.9","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["arch/riscv/kvm/aia_imsic.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/6c2bcf6b173d4afed883cceea9d47f2c5194161d"},{"url":"https://git.kernel.org/stable/c/a29c5d2dd2ef9a8617a9a6d5585696d5f149cd98"},{"url":"https://git.kernel.org/stable/c/c525772c304c971b0d3a1f2898dedbae653efe90"},{"url":"https://git.kernel.org/stable/c/71acbea44e78665ea90e3c310fca6bbdcc0252db"},{"url":"https://git.kernel.org/stable/c/8ae12ccaec6ec74945d8c1ef39f2c1b8df779abc"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:L/I:L/A:H","baseScore":7,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:L - A local process reaches the patched kvm_riscv_aia_imsic_rw_attr() through kvm_device_ioctl() and aia_get_attr()/aia_set_attr() using KVM_GET_DEVICE_ATTR or KVM_SET_DEVICE_ATTR; no network or guest-protocol input reaches it.\nAC:H - The attacker can race its attribute ioctl against KVM_RUN, but cross-owner impact also requires kvm_riscv_aia_alloc_hgei() to reassign the freed per-CPU HGEI to a victim vCPU before imsic_vsfile_rw() runs, which the attacker cannot ensure.\nPR:L - No capable() check guards this path, but the caller must have opened /dev/kvm and created and retained the VM, vCPU, and RISC-V AIA device fds; ordinary authorized KVM-user access suffices without init-namespace administration.\nUI:N - The attacking process itself issues the concurrent KVM_RUN and KVM_GET_DEVICE_ATTR or KVM_SET_DEVICE_ATTR operations; no victim user must mount, open, or approve anything.\nS:C - kvm_riscv_aia_alloc_hgei() uses the global per-CPU aia_hgei owners array rather than a per-VM pool, so the recycled interrupt file can belong to a vCPU in a different VM security boundary.\nC:L - A stale GET makes imsic_vsfile_local_rw() disclose one selected EIDELIVERY, EITHRESHOLD, EIP*, or EIE* word from the new owner's interrupt file, exposing bounded interrupt state rather than arbitrary guest or host memory.\nI:L - A stale SET makes imsic_vsfile_local_rw() write attacker-chosen values to the new owner's delivery, threshold, pending, or enable register, but it provides no arbitrary memory write or demonstrated control-flow primitive.\nA:H - imsic_vsfile_local_rw() can write EIDELIVERY=0 or clear EIE* in the new owner's file; for a single-vCPU victim this suppresses all external-interrupt delivery and can leave guest I/O persistently hung."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-10-24T14:08:57.467Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.5","versionEndExcluding":"6.6.160"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.5","versionEndExcluding":"6.12.112"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.5","versionEndExcluding":"6.18.55"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.5","versionEndExcluding":"7.2.9"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.5","versionEndExcluding":"7.3"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}