KVM: x86: Cancel delayed I/O APIC EOI handling before destroying vCPUs
Summary
| CVE | CVE-2026-74517 |
|---|---|
| State | PUBLISHED |
| Assigner | Linux |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-08-15 13:17:56 UTC |
| Updated | 2026-08-23 13:16:45 UTC |
| Description | In the Linux kernel, the following vulnerability has been resolved: KVM: x86: Cancel delayed I/O APIC EOI handling before destroying vCPUs Cancel (and flush) the I/O APIC's delayed EOI handling work during the "pre VM destroy" phase, before vCPUs are destroyed, as processing the EOI broadcast will inject another IRQ if the line is asserted, i.e. will try to deliver an IRQ to the target vCPU(s). Canceling the work after vCPUs are destroyed leads to UAF if the delayed work is processed after vCPUs are destroyed. BUG: KASAN: slab-use-after-free in __kvm_irq_delivery_to_apic_fast+0x9bf/0xa20 arch/x86/kvm/lapic.c:1250 Read of size 8 at addr ffff8880499abea0 by task kworker/1:2/1218 CPU: 1 UID: 0 PID: 1218 Comm: kworker/1:2 Not tainted 7.1.0-rc7 #5 PREEMPT(lazy) Hardware name: QEMU Ubuntu 25.10 PC v2 (i440FX + PIIX, + 10.1 machine, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 Workqueue: events kvm_ioapic_eoi_inject_work Call Trace: <TASK> __dump_stack lib/dump_stack.c:94 dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 print_report+0x139/0x4ad mm/kasan/report.c:482 kasan_report+0xe4/0x1d0 mm/kasan/report.c:595 __kvm_irq_delivery_to_apic_fast+0x9bf/0xa20 arch/x86/kvm/lapic.c:1250 __kvm_irq_delivery_to_apic+0xd8/0xbf0 arch/x86/kvm/lapic.c:1345 kvm_irq_delivery_to_apic arch/x86/kvm/lapic.h:129 ioapic_service+0x308/0x590 arch/x86/kvm/ioapic.c:492 kvm_ioapic_eoi_inject_work+0x13c/0x190 arch/x86/kvm/ioapic.c:532 process_one_work+0xa59/0x19a0 kernel/workqueue.c:3314 process_scheduled_works kernel/workqueue.c:3397 worker_thread+0x5eb/0xe50 kernel/workqueue.c:3478 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x72b/0xd30 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 </TASK> Note, the VM is unreachable once kvm_destroy_vm() starts, and scheduling new work via kvm_ioapic_send_eoi() can only be done via KVM_RUN, i.e. requires a live vCPU. Alternatively, KVM could simply destroy the I/O APIC during the "pre" phase of VM destruction, but that gets more than a bit sketchy as KVM expects the I/O APIC to exist if ioapic_in_kernel() is true, and nested virtualization in particular has a bad habit of touching VM-scope state during vCPU destruction. E.g. attempting to free the PIC during the pre phase would lead to a NULL pointer dereference in kvm_cpu_has_extint(), and it's not hard to imagine the I/O APIC having a similar flaw. |
Risk And Classification
Primary CVSS: v3.1 9.3 CRITICAL from 416baaa9-dc9f-4396-8d5f-8c081fb06d67
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
EPSS: 0.001380000 probability, percentile 0.033790000 (date 2026-08-24)
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 3.1 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | Secondary | 9.3 | CRITICAL | CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H |
| 3.1 | CNA | DECLARED | 9.3 | CRITICAL | CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H |
CVSS v3.1 Breakdown
Attack Vector
LocalAttack Complexity
LowPrivileges Required
NoneUser Interaction
NoneScope
ChangedConfidentiality
HighIntegrity
HighAvailability
HighCVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Linux | Linux | affected c60f5156e62d0be6c53373b623f16a9e37e2208e 69d040448067cebdd5598684db36ce7d8fb2f43e git | Not specified |
| CNA | Linux | Linux | affected 17bcd714426386fda741a4bccd96a2870179344b 5f0a99ea721203a4063618aafcca32abf573cb96 git | Not specified |
| CNA | Linux | Linux | affected 17bcd714426386fda741a4bccd96a2870179344b ed56a6b58222f9c1f4115a0bd2788dd6ed6022e2 git | Not specified |
| CNA | Linux | Linux | affected 17bcd714426386fda741a4bccd96a2870179344b 9910e835580fef3bef53b70241dd00c4bffad693 git | Not specified |
| CNA | Linux | Linux | affected 6.12.41 6.12.105 semver | Not specified |
| CNA | Linux | Linux | affected 6.14 | Not specified |
| CNA | Linux | Linux | unaffected 6.14 semver | Not specified |
| CNA | Linux | Linux | unaffected 6.12.105 6.12.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.18.46 6.18.* semver | Not specified |
| CNA | Linux | Linux | unaffected 7.1.8 7.1.* semver | Not specified |
| CNA | Linux | Linux | unaffected 7.2 * original_commit_for_fix | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| git.kernel.org/stable/c/5f0a99ea721203a4063618aafcca32abf573cb96 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/ed56a6b58222f9c1f4115a0bd2788dd6ed6022e2 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/69d040448067cebdd5598684db36ce7d8fb2f43e | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/9910e835580fef3bef53b70241dd00c4bffad693 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
No vendor comments have been submitted for this CVE.
There are currently no legacy QID mappings associated with this CVE.