[PATCH 5.10 014/121] parisc: Fix sglist access in ccio-dma.c

Greg Kroah-Hartman
2022-02-21T09:15:11Z

From: John David Anglin <dave.anglin@bell.net>

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@bell.net>
Cc: stable@vger.kernel.org
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
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);