[PATCH] pci: assert that irqnum is between 0 and bus->nirqs in pci_change_irq_level()

[Mark Cave-Ayland]

These assertions similar to those in the adjacent pci_bus_get_irq_level() 
function
ensure that irqnum lies within the valid PCI bus IRQ range.

Signed-off-by: Mark Cave-Ayland <mark.cave-ayl...@ilande.co.uk>
---

This would have immediately picked up on the sabre PCI bus IRQ overflow fixed by
the patch I just posted.

---
 hw/pci/pci.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/hw/pci/pci.c b/hw/pci/pci.c
index 3c8f10b461..b1484b3747 100644
--- a/hw/pci/pci.c
+++ b/hw/pci/pci.c
@@ -258,6 +258,8 @@ static void pci_change_irq_level(PCIDevice *pci_dev, int 
irq_num, int change)
             break;
         pci_dev = bus->parent_dev;
     }
+    assert(irq_num >= 0);
+    assert(irq_num < bus->nirq);
     bus->irq_count[irq_num] += change;
     bus->set_irq(bus->irq_opaque, irq_num, bus->irq_count[irq_num] != 0);
 }
-- 
2.20.1