Bug 2559563 (CVE-2026-98877)

Summary: CVE-2026-98877 kernel: irqchip/gic-v4: Don't advertise VLPIs if no ITS is probed
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: akhatavk, aos-team-art-private, asdas, dpaolell, jdelft, jupierce, lgarciaa, mbiarnes, ppalepu, ppostler, prdhamdh, rhel-process-autobot, sghai, sidsharm, suppawar, vlaad, watson-tool-maintainers
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
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Doc Text:
A flaw was found in the Linux kernel's ARM Generic Interrupt Controller (GIC) driver. When virtual interrupt support is enabled on a system lacking an Interrupt Translation Service (ITS) controller, the kernel fails to disable virtual interrupt advertising. A local user capable of running a virtual machine under these conditions can trigger an unhandled null pointer dereference, causing a kernel crash and resulting in a Denial of Service (DoS).
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:

Description OSIDB Bzimport 2026-10-23 11:59:47 UTC
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.vgic_v4_enable=1” on a system that has
no MSI controller device tree node and GICv4, it results a panic as
“gic_domain” 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 : __irq_domain_instantiate+0x1d4/0x578
    lr : __irq_domain_instantiate+0x1cc/0x578

Set vLPI support to false at init time if the host has no ITS, so it
propagates properly to kvm_vgic_global_state.has_gicv4.