{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-89913", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-11T19:38:34.774Z", "datePublished": "2026-09-16T10:32:09.947Z", "dateUpdated": "2026-10-21T12:49:08.468Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-21T12:49:08.468Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: arm64: vgic-v3: take an LPI reference in vgic_v3_save_pending_tables\n\nvgic_v3_save_pending_tables() iterates dist->lpi_xa using xa_for_each()\nand dereferences the returned struct vgic_irq in the loop body without\nholding a reference on the LPI.\n\nThe xarray iterator only provides temporary RCU coverage while looking up\nthe current entry. That is not sufficient for this loop body, which reads\nfields from struct vgic_irq and performs guest memory accesses before the\niteration completes.\n\nA concurrent path can trigger this race: the irqfd cached injection path\n(vgic_its_inject_cached_translation) obtains a transient LPI reference\nvia vgic_its_check_cache() without holding kvm->lock, vcpu->mutex,\nconfig_lock, or its_lock. If guest ITS DISCARD then drops the cache and\nITE references under its_lock, the transient inject reference may become\nthe final one. When vgic_put_irq() drops it, the LPI is erased from\nlpi_xa and freed via kfree_rcu(). Meanwhile, vgic_v3_save_pending_tables()\nmay still hold a stale pointer obtained from the xarray iterator and\ndereference it after the RCU grace period completes.\n\nFix this by re-fetching each iterated LPI via vgic_get_irq(), which takes\na stable reference, and dropping it with vgic_put_irq() on all paths.\nThis matches the pattern already used by other lpi_xa iterators in the\nvgic ITS code." } ], "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 - The UAF is reached only via local KVM: KVM_SET_DEVICE_ATTR(KVM_DEV_ARM_VGIC_SAVE_PENDING_TABLES) on the VGIC device fd, irqfd/KVM_SIGNAL_MSI cached injection, and guest GICv3 ITS MMIO writes to GITS_CWRITER (DISCARD); there is no network, adjacent, or physical path.\nAC:L - A kvm-group attacker who owns the VMM controls every side of the race (irqfd/KVM_SIGNAL_MSI cached inject, guest ITS DISCARD, and SAVE_PENDING_TABLES). The save path sleeps in kvm_read_guest_lock() so the kfree_rcu() window is attacker-driven rather than an uninfluenced host condition.\nPR:L - Creating a VM and issuing VGIC device attributes requires only /dev/kvm access (typically 0660 kvm group) or tenancy in an arm64 KVM guest; kvm_dev_ioctl_create_vm() and kvm_device_ioctl() have no capable() gate, so init-namespace root is not required.\nUI:N - The attacker issues the VGIC save ioctl, irqfd/MSI injection, and guest ITS DISCARD themselves; no separate victim action such as mounting a filesystem or opening a crafted file is required.\nS:C - Use-after-free of host-kernel struct vgic_irq in KVM's VGIC ITS LPI xarray crosses the guest-to-host hypervisor boundary; corrupting host LPI objects from a VM/VMM can escape the guest security authority.\nC:H - This is a host-kernel use-after-free of struct vgic_irq after kfree_rcu(); reclaiming the freed object lets the save loop read attacker-controlled irq fields (target_vcpu, intid, pending_latch), yielding an arbitrary host kernel read primitive.\nI:H - Host heap UAF of vgic_irq with attacker-controlled irqfd/DISCARD timing enables heap spray of fake irq objects, providing write and control-flow hijack primitives against the host kernel.\nA:H - Dereferencing the freed vgic_irq after the RCU grace period (the save path sleeps in kvm_read_guest_lock()) causes a host kernel oops or panic even without a full exploit." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "arch/arm64/kvm/vgic/vgic-v3.c" ], "versions": [ { "version": "280771252c1bae0947215c59fb9ea6a8d9f8399d", "lessThan": "4000462866bc71f16d1bfb3cf8e969f95150cd64", "status": "affected", "versionType": "git" }, { "version": "280771252c1bae0947215c59fb9ea6a8d9f8399d", "lessThan": "7631f95297560157d3a9283cb999e3be00103348", "status": "affected", "versionType": "git" }, { "version": "280771252c1bae0947215c59fb9ea6a8d9f8399d", "lessThan": "d3a2d20b7248ea67465af1cf79c79f90ff70926c", "status": "affected", "versionType": "git" }, { "version": "280771252c1bae0947215c59fb9ea6a8d9f8399d", "lessThan": "f5b8f203bfc07a5a257dff859e66d2c500f9f509", "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/arm64/kvm/vgic/vgic-v3.c" ], "versions": [ { "version": "4.12", "status": "affected" }, { "version": "0", "lessThan": "4.12", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.114", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.51", "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": "4.12", "versionEndExcluding": "6.12.114" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.12", "versionEndExcluding": "6.18.51" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.12", "versionEndExcluding": "7.2.5" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.12", "versionEndExcluding": "7.3" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/4000462866bc71f16d1bfb3cf8e969f95150cd64" }, { "url": "https://git.kernel.org/stable/c/7631f95297560157d3a9283cb999e3be00103348" }, { "url": "https://git.kernel.org/stable/c/d3a2d20b7248ea67465af1cf79c79f90ff70926c" }, { "url": "https://git.kernel.org/stable/c/f5b8f203bfc07a5a257dff859e66d2c500f9f509" } ], "title": "KVM: arm64: vgic-v3: take an LPI reference in vgic_v3_save_pending_tables", "x_generator": { "engine": "bippy-1.2.0" } } } }