In the Linux kernel, the following vulnerability has been resolved: drm/vc4: Disable the V3D interrupt across runtime suspend vc4_irq_disable()… (CVE-2026-98946)

The vulnerability in the Linux kernel's drm/vc4 driver relates to improper handling of the V3D interrupt during runtime suspend. The function vc4_irq_disable() masks V3D interrupt sources and calls synchronize_irq(), but on Raspberry Pi models 0-3 using the ARMCTRL interrupt controller, synchronize_irq() does not fully quiesce the interrupt handler because ARMCTRL lacks an active interrupt state. Consequently, the interrupt handler vc4_irq() may execute after the power domain is off, reading invalid register values (0xdeadbeef) that trigger spurious interrupts. Although some functions return early when no job pointer is present, the OUTOMEM condition can still schedule overflow memory work after interrupts are disabled. The fix involves disabling the interrupt line across the power management transition and adjusting the interrupt installation to request the IRQ line disabled before the first runtime resume, preserving enable/disable balance.

The vulnerability could cause the interrupt handler to run after the power domain is off, leading to spurious interrupts and scheduling of overflow memory work unexpectedly. This may affect system stability or behavior during power transitions on affected hardware (notably Raspberry Pi 0-3). There is no indication of direct memory corruption or privilege escalation. No known exploits in the wild have been reported.

A fix has been implemented in the Linux kernel drm/vc4 driver to disable the V3D interrupt line across runtime suspend transitions, preventing spurious interrupts. Users should update to a kernel version that includes this fix. No additional mitigation steps are indicated.