CVE-2026-98877: irqchip/gic-v4: Don't advertise VLPIs if no ITS is probed
In the Linux kernel, the following vulnerability has been resolved:
irqchip/gic-v4: Don't advertise VLPIs if no ITS is probed
When accidentally setting “kvm-arm.vgicv4enable=1” on a system that has no MSI controller device tree node and GICv4, it results a panic as “gicdomain” is NULL and the kernel attempts to access it.
Unable to handle kernel NULL pointer dereference at virtual address 0000000000000028 Mem abort info: ESR = 0x0000000096000006
CPU: 1 UID: 0 PID: 295 Comm: lkvm-static Not tainted 7.1.0-rc4-ge3f15ad3970e #5 PREEMPT Hardware name: linux,dummy-virt (DT) pstate: 81402005 (Nzcv daif +PAN -UAO -TCO +DIT -SSBS BTYPE=--) pc : irqdomaininstantiate+0x1d4/0x578 lr : irqdomaininstantiate+0x1cc/0x578
Set vLPI support to false at init time if the host has no ITS, so it propagates properly to kvmvgicglobalstate.hasgicv4.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Configuration
Disable vGICv4 support when the host has no ITS; do not set kvm-arm.vgic_v4_enable=1 on systems without an ITS.
KVM ARM kvm-arm.vgic_v4_enable = 0