[PATCH] x86, pci-nommu: fix potential NULL-ptr dereference incheck_addr()

[Arne Redlich]

check_addr() dereferences hwdev->dma_mask without first checking
that it's actually non-NULL.

Signed-off-by: Arne Redlich <arne.redlich@xxxxxxxxxxxxxx>
---
 arch/x86/kernel/pci-nommu.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/arch/x86/kernel/pci-nommu.c b/arch/x86/kernel/pci-nommu.c
index 3af4af8..55b49c7 100644
--- a/arch/x86/kernel/pci-nommu.c
+++ b/arch/x86/kernel/pci-nommu.c
@@ -16,7 +16,7 @@ static int
 check_addr(char *name, struct device *hwdev, dma_addr_t bus, size_t size)
 {
        if (hwdev && !dma_capable(hwdev, bus, size)) {
-               if (*hwdev->dma_mask >= DMA_BIT_MASK(32))
+               if (hwdev->dma_mask && *hwdev->dma_mask >= DMA_BIT_MASK(32))
                        printk(KERN_ERR
                            "nommu_%s: overflow %Lx+%zu of device mask %Lx\n",
                                name, (long long)bus, size,
-- 
1.7.4.1


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