{ "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": "2026-10-19T08:54:39.939Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-19T08:54:39.939Z" }, "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": "506f03b5f869cbae50d31b50d80d4a5735d47f94", "status": "affected", "versionType": "git" }, { "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": "6.18.57", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2.5", "lessThanOrEqual": "7.2.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.3", "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": "6.18.57" }, { "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" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/506f03b5f869cbae50d31b50d80d4a5735d47f94" }, { "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" } } } }