[PATCH 4.19 05/58] parisc: Fix sglist access in ccio-dma.c

[Greg Kroah-Hartman]

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
@@ -1010,7 +1010,7 @@ 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;
@@ -1018,6 +1018,7 @@ 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);