There is a vector setup race, which overwrites the interrupt descriptor in the per CPU vector array resulting in a disfunctional device. CPU0 CPU1 interrupt is raised in APIC IRR but not handled free_irq() per_cpu(vector_irq, CPU1)[vector] = VECTOR_SHUTDOWN; request_irq() common_interrupt() d = this_cpu_read(vector_irq[vector]); per_cpu(vector_irq, CPU1)[vector] = desc; if (d == VECTOR_SHUTDOWN) this_cpu_write(vector_irq[vector], VECTOR_UNUSED); free_irq() cannot observe the pending vector in the CPU1 APIC as there is no way to query the remote CPUs APIC IRR. This requires that request_irq() uses the same vector/CPU as the one which was freed, but this also can be triggered by a spurious interrupt. Interestingly enough this problem managed to be hidden for more than a decade. Prevent this by reevaluating vector_irq under the vector lock, which is held by the interrupt activation code when vector_irq is updated. Fixes: 9345005f4eed ("x86/irq: Fix do_IRQ() interrupt warning for cpu hotplug retriggered irqs") Cc: stable@vger.kernel.org#5.15.x Cc: gregkh@linuxfoundation.org Jacob Pan (1): x86/irq: Factor out handler invocation from common_interrupt() Thomas Gleixner (1): x86/irq: Plug vector setup race arch/x86/kernel/irq.c | 70 ++++++++++++++++++++++++++++++++++--------- 1 file changed, 56 insertions(+), 14 deletions(-) -- 2.34.1