From: John David Anglin <dave.anglin@bell.net>
Date: Thu, 27 Jan 2022 22:33:41 +0000 (+0000)
Subject: parisc: Fix sglist access in ccio-dma.c
X-Git-Tag: v4.19.231~55
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=a32bb343edc9c6dbce3b2679795bfb76b0bf5f60;p=users%2Fdwmw2%2Flinux.git

parisc: Fix sglist access in ccio-dma.c

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>
---

diff --git a/drivers/parisc/ccio-dma.c b/drivers/parisc/ccio-dma.c
index b7b2e811d5471..6efab7a06c5fc 100644
--- a/drivers/parisc/ccio-dma.c
+++ b/drivers/parisc/ccio-dma.c
@@ -1010,7 +1010,7 @@ ccio_unmap_sg(struct device *dev, struct scatterlist *sglist, int nents,
 	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 scatterlist *sglist, int nents,
 		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);