[12/55] intel-iommu: Fix use after release during device attach

[Greg KH]

2.6.38-stable review patch.  If anyone has any objections, please let us know.

------------------

From: Jan Kiszka <jan.kiszka@xxxxxxxxxxx>

commit 7a6610139a1e1d9297dd1c5d178022eac36839cb upstream.

Obtain the new pgd pointer before releasing the page containing this
value.

Signed-off-by: Jan Kiszka <jan.kiszka@xxxxxxxxxxx>
Reviewed-by: Sheng Yang <sheng@xxxxxxxxxxxxxxx>
Signed-off-by: David Woodhouse <David.Woodhouse@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>

---
 drivers/pci/intel-iommu.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/pci/intel-iommu.c
+++ b/drivers/pci/intel-iommu.c
@@ -3627,9 +3627,9 @@ static int intel_iommu_attach_device(str
 
 		pte = dmar_domain->pgd;
 		if (dma_pte_present(pte)) {
-			free_pgtable_page(dmar_domain->pgd);
 			dmar_domain->pgd = (struct dma_pte *)
 				phys_to_virt(dma_pte_addr(pte));
+			free_pgtable_page(pte);
 		}
 		dmar_domain->agaw--;
 	}


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