drm/vc4: Disable the V3D interrupt across runtime suspend

Summary

In the Linux kernel, the following vulnerability has been resolved: drm/vc4: Disable the V3D interrupt across runtime suspend vc4_irq_disable() masks the V3D interrupt sources and then calls synchronize_irq() before the V3D is powered down. However, by itself, this is not enough to quiesce the interrupt handler. synchronize_irq() waits for handlers that have already set IRQD_IRQ_INPROGRESS, and for irqchips reporting IRQCHIP_STATE_ACTIVE. A GIC interrupt chip is able to mark an interrupt active as soon as a CPU acknowledges it, so there these checks cover the whole dispatch path. On RPi 0-3, however, the interrupt controller is ARMCTRL, which has no active state. A CPU that has read the hwirq out of the pending register but has not yet reached handle_level_irq() stays invisible to synchronize_irq(). During a power transition, vc4_irq() may therefore run after the power domain is off, where every V3D register read will return 0xdeadbeef. 0xdeadbeef has FLDONE, FRDONE and OUTOMEM set. This problem doesn't trigger NULL pointer dereference issues only because the functions vc4_irq_finish_bin_job() and vc4_irq_finish_render_job() return early when there is no job pointer, but OUTOMEM is still able to schedule vc4_overflow_mem_work() after vc4_irq_disable() has already cancelled it. Therefore, fix the spurious interrupts by disabling the interrupt line across the PM transition. To preserve the enable/disable balance, move vc4_irq_install() and request the IRQ line disabled before the first runtime resume.

Timeline

1. Oct 23, 2026, 12:19 PM UTCCVE published
2. Oct 23, 2026, 12:20 PM UTCFirst seen by cve.now

Affected versions

• Linux Linux

  From 9b6f461582e6b07e2ce93227a3e4661846e594ad · fixed in e81402c3d42041356cb7978510ebab997bc8d411; From 9b6f461582e6b07e2ce93227a3e4661846e594ad · fixed in 6abc8e4dcfbc1d26a94c0ac037dfb3716f686b1f

• Linux Linux

  6.1

• KernelLinux

  From 6.1.0 · fixed in 7.2.11

References 2