[SPARC64]: Fix memory corruption in pci_4u_free_consistent().

The second argument to free_npages() was being incorrectly
calculated, which would thus access far past the end of the
arena->map[] bitmap.

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 1 insertions, 1 deletions

diff --git a/arch/sparc64/kernel/pci_iommu.c b/arch/sparc64/kernel/pci_iommu.c
index 82e5455134c6..2e7f1427088a 100644
--- a/arch/sparc64/kernel/pci_iommu.c
+++ b/arch/sparc64/kernel/pci_iommu.c
@@ -281,7 +281,7 @@ static void pci_4u_free_consistent(struct pci_dev *pdev, size_t size, void *cpu,
 
         spin_lock_irqsave(&iommu->lock, flags);
 
-        free_npages(iommu, dvma, npages);
+        free_npages(iommu, dvma - iommu->page_table_map_base, npages);
 
         spin_unlock_irqrestore(&iommu->lock, flags);