From 8211a7b5857914058c52ae977c96463e419b37ab Mon Sep 17 00:00:00 2001 From: Troy Heber Date: Wed, 19 Aug 2009 15:26:11 -0600 Subject: [PATCH] pci/dmar: correct off-by-one error in dmar_fault() DMAR faults are recorded into a ring of "fault recording registers". fault_index is a 0-based index into the ring. The code allows the 0-based fault_index to be equal to the total number of fault registers available from the cap_num_fault_regs() macro, which causes access beyond the last available register. Signed-off-by Troy Heber Signed-off-by: David Woodhouse --- drivers/pci/dmar.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/pci/dmar.c b/drivers/pci/dmar.c index 380b60e677e0..3264b626725a 100644 --- a/drivers/pci/dmar.c +++ b/drivers/pci/dmar.c @@ -1226,7 +1226,7 @@ irqreturn_t dmar_fault(int irq, void *dev_id) source_id, guest_addr); fault_index++; - if (fault_index > cap_num_fault_regs(iommu->cap)) + if (fault_index >= cap_num_fault_regs(iommu->cap)) fault_index = 0; spin_lock_irqsave(&iommu->register_lock, flag); }