CVE-2026-98390

About vulnerability

In the Linux kernel, the following vulnerability has been resolved:

x86/amd_node: Avoid divide by zero on virtualized systems

On a virtualized system, the number of nodes does not have a relationship to the number of roots. A Xen PVH dom0 can calculate roots_per_node as 0, which crashes with a divide by zero in:

if (count++ % roots_per_node)

because the underlying topology code on Xen ends up making num_nodes 2 and num_roots 1 and the integer division result is 0.

The issue is seen with Xen, but it could affect other systems.

Set roots_per_node to 1 in this case. Print a firmware bug when this is performed for non-virtualized systems.

[ bp: Massage commit message. ]

Affected product:

AlmaLinux 9.2 ESU , TuxCare 9.6 ESU , TuxCare 9.8 ESU

Affected packages:

kernel @ 5.14.0 (+2 more)

Live-patch status from KernelCare for each operating system.