From: John David Anglin <dave.anglin@xxxxxxxx> commit d7da660cab47183cded65e11b64497d0f56c6edf upstream. This patch implements the same bug fix to ccio-dma.c as to sba_iommu.c. It ensures that only the allocated entries of the sglist are accessed. Signed-off-by: John David Anglin <dave.anglin@xxxxxxxx> Cc: stable@xxxxxxxxxxxxxxx Signed-off-by: Helge Deller <deller@xxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/parisc/ccio-dma.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/drivers/parisc/ccio-dma.c +++ b/drivers/parisc/ccio-dma.c @@ -1003,7 +1003,7 @@ ccio_unmap_sg(struct device *dev, struct ioc->usg_calls++; #endif - while(sg_dma_len(sglist) && nents--) { + while (nents && sg_dma_len(sglist)) { #ifdef CCIO_COLLECT_STATS ioc->usg_pages += sg_dma_len(sglist) >> PAGE_SHIFT; @@ -1011,6 +1011,7 @@ ccio_unmap_sg(struct device *dev, struct ccio_unmap_page(dev, sg_dma_address(sglist), sg_dma_len(sglist), direction, 0); ++sglist; + nents--; } DBG_RUN_SG("%s() DONE (nents %d)\n", __func__, nents);