get_irte() can race with free_irte() and dereference a NULL iommu
pointer.

Signed-off-by: Greg Edwards <gedwa...@ddn.com>
Cc: sta...@vger.kernel.org
---
 drivers/iommu/intel_irq_remapping.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/iommu/intel_irq_remapping.c 
b/drivers/iommu/intel_irq_remapping.c
index 9b17489..2d67e6d 100644
--- a/drivers/iommu/intel_irq_remapping.c
+++ b/drivers/iommu/intel_irq_remapping.c
@@ -70,6 +70,12 @@ static int get_irte(int irq, struct irte *entry)
 
        raw_spin_lock_irqsave(&irq_2_ir_lock, flags);
 
+       /* ensure we're not racing with free_irte() */
+       if (unlikely(!irq_iommu->iommu)) {
+               raw_spin_unlock_irqrestore(&irq_2_ir_lock, flags);
+               return -1;
+       }
+
        index = irq_iommu->irte_index + irq_iommu->sub_handle;
        *entry = *(irq_iommu->iommu->ir_table->base + index);
 
-- 
1.9.3

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Reply via email to