CVE-2025-40136 crypto: hisilicon/qm - request reserved interrupt for virtual function
A missing interrupt registration in the Hisilicon QM driver causes a kernel warning and potential instability when virtual functions are passed through to VMs with GICv4 enabled.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2025-40136?
CVE-2025-40136 is a denial of service vulnerability in Linux, published on 12 Nov 2025. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
crypto: hisilicon/qm - request reserved interrupt for virtual function
The device interrupt vector 3 is an error interrupt for physical function and a reserved interrupt for virtual function. However, the driver has not registered the reserved interrupt for virtual function. When allocating interrupts, the number of interrupts is allocated based on powers of two, which includes this interrupt. When the system enables GICv4 and the virtual function passthrough to the virtual machine, releasing the interrupt in the driver triggers a warning.
The WARNING report is: WARNING: CPU: 62 PID: 14889 at arch/arm64/kvm/vgic/vgic-its.c:852 its_free_ite+0x94/0xb4
Therefore, register a reserved interrupt for VF and set the IRQF_NO_AUTOEN flag to avoid that warning.
Which versions are affected by CVE-2025-40136?
How do I fix CVE-2025-40136?
Apply the vendor's patch.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2025-40136 being exploited?
There is no known exploitation of CVE-2025-40136 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2025-40136, DEBIAN-CVE-2025-40136, GHSA-p5f2-4xpv-wwqj, ROOT-OS-DEBIAN-12-CVE-2025-40136, ROOT-OS-DEBIAN-13-CVE-2025-40136, ROOT-OS-UBUNTU-2404-CVE-2025-40136 and 1 more.