In the Linux kernel, the following vulnerability has been resolved: virt: vmgenid: set driver_data before registering notification handlers Both… (CVE-2026-98841)

The Linux kernel vmgenid driver had a race condition where notification handlers were registered before the driver_data pointer was set. This allowed asynchronous notifications or interrupts to trigger the handler which dereferenced a NULL driver_data pointer, causing a kernel panic. The problem existed in both the device tree and ACPI probe paths. The fix involved assigning driver_data before registering notification handlers, ensuring handlers operate on fully initialized state and preventing NULL pointer dereference panics.

The vulnerability could cause a kernel panic due to a NULL pointer dereference when notification handlers are triggered before driver_data is initialized. This results in system instability or crashes, particularly during guest snapshot restore operations or when shared IRQ lines trigger early notifications.

A fix has been implemented in the Linux kernel to assign driver_data before registering notification handlers. Users should update to the fixed kernel version once available. Patch status is not explicitly confirmed in the provided data; check the vendor advisory for current remediation guidance.