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CVE-2026-72288
KVM: arm64: vgic: Handle race between interrupt affinity change and LPI disabling
Published 2026-08-15 (2 months ago) by the Linux kernel CNA. Subsystem arch/arm64. Debian urgency: not yet assigned.
What to do, per Debian release
Debian's own status for CVE-2026-72288 in every release this site tracks, and what each one means in practice. Every status below is the one the Debian Security Team publishes for this CVE. source
| Release | Status | Version | What this means |
|---|---|---|---|
| Debian 12bookworm | vulnerable | 6.1.190-1 | No fix published anywhere yet, neither in Debian nor upstream for the series bookworm tracks. Watch the Debian tracker page for this CVE. Advisories for bookworm have historically landed a median of 23 days after publication. |
| Debian 13trixie | vulnerable | 6.12.113-1 | No fix published anywhere yet, neither in Debian nor upstream for the series trixie tracks. Watch the Debian tracker page for this CVE. Advisories for trixie have historically landed a median of 11 days after publication. |
| Debian 14forky | fixed | 7.1.5-1 | Update the kernel and reboot. Fixed in 7.1.5-1. A running kernel keeps the old code until the machine restarts. |
| Debian unstablesid | fixed | 7.1.5-1 | Update the kernel and reboot. Fixed in 7.1.5-1. A running kernel keeps the old code until the machine restarts. |
The vulnerability
What the bug is
Hyunwoo Kim reports some really bad races should the following situation occur: - LPI-I is pending in vcpu-B's AP list - vcpu-A writes to vcpu-B's RD to disable its LPIs - vcpu-C moves I from B to C If the last two race nicely enough, vgic_prune_ap_list() can drop the irq and AP list locks, reacquire them, and in the interval the irq has been freed. UAF follows. The fix is two-fold: - Before dropping the irq and ap_list locks, take a reference on the irq - Do not try to handle migration of the pending bit: there is no expectation that this state is retained, as per the architecture With that, we're sure that the interrupt is still around, and we safely remove it from the AP list as it has no target at this stage (unless another interrupt fires, but that's another story).
Where it lives
The fix touches these files. If the subsystem is one you do not use, the practical exposure is lower, though the package is still the vulnerable one.
arch/arm64/kvm/vgic/vgic.c
- What this is
- KERNEL VIRTUAL MACHINE FOR ARM64 (KVM/arm64)MAINTAINERS section matched on arch/arm64/kvm/ · linux-arm-kernel@lists.infradead.org · Maintained
Show whether Debian builds this, per release
Not established. This site could not find the build rule for the affected file in the kernel trees Debian ships, so it has no answer about whether Debian compiles this code. Read that as unknown, never as absent.
- bookworm, trixie, forky, sid?
- ?
- not established - no Makefile entry for the affected file
Where a release above reads "not established", no build rule for the affected file was found in that release's kernel tree. That is a gap in this lookup, not a finding that the code is absent.
From the configuration Debian publishes for every kernel flavour it builds. It covers only the architectures Debian ships a linux-config package for, and nothing about a kernel you built yourself. Debian's own status above stays authoritative about the source package.MAINTAINERS
Signals
- Published
- 2026-08-15 (2 months ago)source
- CVSS
- 9.3 critical
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:Hsource recompute it - Attack vector
- local (AV:L)source
- EPSS
- 0.18%, higher than 7.4% of all CVEssource
- CISA KEV
- not listedthe KEV catalogue
- Debian urgency
- not yet assignedsource
- Subsystem
- arch/arm64
Upstream fixes
The versions the CNA records as introducing and fixing this, and the commit for each. source
| Introduced | Fixed in | Commit |
|---|---|---|
| 4.8 | 6.18.40 | d19dca8194eb |
| 4.8 | 7.1.5 | b1a89d12d35a |
| 4.8 | 7.2 | 7258770e5814 |
Why the CNA scored it this way
Quoted from the kernel CNA's own scoring file, word for word. A highlighted metric carries the most severe value CVSS v3.1 defines for it, which is what pushes the score up. source
- AV:LAttack vector, local
- The flaw is reached only from KVM guest MMIO traps on GICv3 redistributor GICR_CTLR LPI-disable writes, ITS MOVI affinity changes, and vCPU-exit paths into vgic_prune_ap_list(); no network-facing host protocol is involved.
- AC:LAttack complexity, low
- A guest controls all three racing vCPUs by pinning threads to concurrently issue ITS MOVI, cross-vCPU GICR_CTLR LPI-disable writes, and vCPU exits that invoke vgic_prune_ap_list(); the attacker creates and wins the race rather than depending on uncontrollable host timing.
- PR:NPrivileges required, none
- No host privileges are required beyond running code in an assigned KVM guest (e.g. a cloud VM tenant on arm64); exploitation needs guest-kernel access to GIC/ITS MMIO, not host root or capabilities in the init namespace.
- UI:NUser interaction, none
- Exploitation is fully attacker-driven from within a multi-vCPU guest VM and does not require any victim user or administrator action on the host.
- S:CScope, changed
- The use-after-free corrupts host-kernel heap memory (struct vgic_irq) from guest-controlled VGIC operations, crossing the guest-to-host virtualization security boundary with VM-escape impact.
- C:HConfidentiality impact, high
- vgic_flush_pending_lpis() can free the LPI vgic_irq while vgic_prune_ap_list() still dereferences it after reacquiring dropped locks, yielding a kernel heap use-after-free exploitable for arbitrary host memory disclosure via heap grooming.
- I:HIntegrity impact, high
- The dangling vgic_irq pointer permits attacker-influenced writes through irq_lock, list_head, vcpu, and target_vcpu fields during ap_list migration, enabling host control-flow or data corruption primitives.
- A:HAvailability impact, high
- The race frees live kernel objects still referenced by the ap_list migration path, causing host kernel oops, panic, or hang during list_del, lock operations, or subsequent LPI delivery on arm64 KVM hosts.