{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-89907","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2026-09-11T19:38:34.774Z","datePublished":"2026-09-16T10:32:05.925Z","dateUpdated":"2026-09-16T14:39:57.195Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-09-16T14:39:57.195Z"},"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nLoongArch: KVM: Validate MSI data before routing it to EIOINTC\n\npch_msi_set_irq() passes e->msi.data straight into eiointc_set_irq() as\nthe irq number. The MSI data comes from userspace, that either via a\nKVM_IRQ_ROUTING_MSI entry set with KVM_SET_GSI_ROUTING (used by irqfd\nand KVM_IRQ_LINE) or directly via KVM_SIGNAL_MSI, and is never checked\nagainst EIOINTC_IRQS.\n\neiointc_set_irq() uses the value with __set_bit()/__clear_bit() on the\n256-bit isr bitmap, eiointc_update_irq() then indexes sw_coremap[] and\nthe per-cpu coreisr/sw_coreisr bitmaps with it. Therefore a data value\n>= 256 reads and writes memory past the end of those arrays, i.e. any\nprocess holding a VM fd can corrupt kernel memory beyond the allocation\nof loongarch_eiointc.\n\nReject MSI data that doesn't fit in the EIOINTC irq space. The DMSINTC\npath is unaffected as it decodes the vector from the address and masks\nit."}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H","baseScore":8.8,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:L - pch_msi_set_irq() is reached only via local KVM VM-fd ioctls on /dev/kvm: KVM_SIGNAL_MSI, or KVM_SET_GSI_ROUTING with a KVM_IRQ_ROUTING_MSI entry then irqfd/KVM_IRQ_LINE. No network, Bluetooth, or physical path supplies the unbounded MSI data.\nAC:L - A single KVM_SIGNAL_MSI (or irqfd injection after installing a KVM_IRQ_ROUTING_MSI entry) with attacker-chosen msi.data >= 256 deterministically drives __set_bit()/__clear_bit() on isr and indexes sw_coremap[] past EIOINTC_IRQS; the attacker fully controls the irq index with no race or uncontrollable layout.\nPR:L - Exploitation requires only opening /dev/kvm and holding a VM fd (kvm-group membership on typical LoongArch hosts, or equivalent unprivileged VM access), then creating the in-kernel EIOINTC/PCH-PIC/IPI devices. Init-namespace root is not required.\nUI:N - No victim interaction is required. The attacker creates the in-kernel LoongArch irqchip devices on a VM they control and issues KVM_SIGNAL_MSI or irqfd themselves; no mount, file open, or other user action is needed.\nS:C - A KVM VM operator corrupts host kernel memory beyond the loongarch_eiointc allocation from the KVM userspace interface, crossing the VM-to-host virtualization boundary rather than confining impact to the attacker's VM security scope.\nC:H - Unbounded msi.data causes out-of-bounds __set_bit()/__clear_bit() on the 256-bit isr bitmap and an out-of-bounds sw_coremap[irq] read past the loongarch_eiointc object. Per kernel guidance such OOB memory corruption is High confidentiality impact.\nI:H - The attacker fully controls the bit index via 32-bit MSI data, yielding arbitrary-offset bit set/clear from s->isr and further OOB writes into coreisr/sw_coreisr when a valid vCPU id is observed. That out-of-bounds write is usable for host privilege escalation.\nA:H - Indexing the EIOINTC bitmaps and sw_coremap[] with irq >= 256 can immediately oops or panic the host kernel, and corrupting adjacent slab objects breaks later irq injection, denying service to the host and co-resident VMs."}]}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["arch/loongarch/kvm/intc/pch_pic.c"],"versions":[{"version":"1928254c5ccb7bdffd7f0334e1ce250e9ce4de94","lessThan":"83715a40a2d30d23719e0b25380ba82ff905195b","status":"affected","versionType":"git"},{"version":"1928254c5ccb7bdffd7f0334e1ce250e9ce4de94","lessThan":"501514d6ebd2111c353a1296f25dbe22fbd64657","status":"affected","versionType":"git"}]},{"product":"Linux","vendor":"Linux","defaultStatus":"affected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["arch/loongarch/kvm/intc/pch_pic.c"],"versions":[{"version":"6.13","status":"affected"},{"version":"0","lessThan":"6.13","status":"unaffected","versionType":"semver"},{"version":"7.2.5","lessThanOrEqual":"7.2.*","status":"unaffected","versionType":"semver"},{"version":"7.3-rc2","lessThanOrEqual":"*","status":"unaffected","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.13","versionEndExcluding":"7.2.5"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.13","versionEndExcluding":"7.3-rc2"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/83715a40a2d30d23719e0b25380ba82ff905195b"},{"url":"https://git.kernel.org/stable/c/501514d6ebd2111c353a1296f25dbe22fbd64657"}],"title":"LoongArch: KVM: Validate MSI data before routing it to EIOINTC","x_generator":{"engine":"bippy-1.2.0"}}}}