Messages in this thread Patch in this message | | | Date | Tue, 22 Jul 2014 08:27:19 -0600 | From | Greg Edwards <> | Subject | [PATCH] iommu/vt-d: fix race between free_irte() and get_irte() |
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get_irte() can race with free_irte() and dereference a NULL iommu pointer.
Signed-off-by: Greg Edwards <gedwards@ddn.com> Cc: stable@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
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