[PATCH] mmc: wbsd: implement check for dma mapping error

[PATCH] mmc: wbsd: implement check for dma mapping error

[Alexey Khoroshilov]

wbsd_request_dma() does not check for dma mapping errors.

Found by Linux Driver Verification project (linuxtesting.org).

Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
---
 drivers/mmc/host/wbsd.c | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/drivers/mmc/host/wbsd.c b/drivers/mmc/host/wbsd.c
index c3fd16d997ca..80a3b11f3217 100644
--- a/drivers/mmc/host/wbsd.c
+++ b/drivers/mmc/host/wbsd.c
@@ -1395,23 +1395,25 @@ static void wbsd_request_dma(struct wbsd_host *host, int dma)
 	 */
 	host->dma_addr = dma_map_single(mmc_dev(host->mmc), host->dma_buffer,
 		WBSD_DMA_SIZE, DMA_BIDIRECTIONAL);
+	if (dma_mapping_error(mmc_dev(host->mmc), host->dma_addr))
+		goto kfree;
 
 	/*
 	 * ISA DMA must be aligned on a 64k basis.
 	 */
 	if ((host->dma_addr & 0xffff) != 0)
-		goto kfree;
+		goto unmap;
 	/*
 	 * ISA cannot access memory above 16 MB.
 	 */
 	else if (host->dma_addr >= 0x1000000)
-		goto kfree;
+		goto unmap;
 
 	host->dma = dma;
 
 	return;
 
-kfree:
+unmap:
 	/*
 	 * If we've gotten here then there is some kind of alignment bug
 	 */
@@ -1421,6 +1423,7 @@ static void wbsd_request_dma(struct wbsd_host *host, int dma)
 		WBSD_DMA_SIZE, DMA_BIDIRECTIONAL);
 	host->dma_addr = 0;
 
+kfree:
 	kfree(host->dma_buffer);
 	host->dma_buffer = NULL;
 
@@ -1434,7 +1437,7 @@ static void wbsd_request_dma(struct wbsd_host *host, int dma)
 
 static void wbsd_release_dma(struct wbsd_host *host)
 {
-	if (host->dma_addr) {
+	if (!dma_mapping_error(mmc_dev(host->mmc), host->dma_addr)) {
 		dma_unmap_single(mmc_dev(host->mmc), host->dma_addr,
 			WBSD_DMA_SIZE, DMA_BIDIRECTIONAL);
 	}
-- 
2.7.4

Re: [PATCH] mmc: wbsd: implement check for dma mapping error

[Ulf Hansson]

On 11 November 2016 at 22:42, Alexey Khoroshilov <khoroshilov@ispras.ru> wrote:
> wbsd_request_dma() does not check for dma mapping errors.
>
> Found by Linux Driver Verification project (linuxtesting.org).
>
> Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>

Thanks, applied for next!

Kind regards
Uffe

> ---
>  drivers/mmc/host/wbsd.c | 11 +++++++----
>  1 file changed, 7 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/mmc/host/wbsd.c b/drivers/mmc/host/wbsd.c
> index c3fd16d997ca..80a3b11f3217 100644
> --- a/drivers/mmc/host/wbsd.c
> +++ b/drivers/mmc/host/wbsd.c
> @@ -1395,23 +1395,25 @@ static void wbsd_request_dma(struct wbsd_host *host, int dma)
>          */
>         host->dma_addr = dma_map_single(mmc_dev(host->mmc), host->dma_buffer,
>                 WBSD_DMA_SIZE, DMA_BIDIRECTIONAL);
> +       if (dma_mapping_error(mmc_dev(host->mmc), host->dma_addr))
> +               goto kfree;
>
>         /*
>          * ISA DMA must be aligned on a 64k basis.
>          */
>         if ((host->dma_addr & 0xffff) != 0)
> -               goto kfree;
> +               goto unmap;
>         /*
>          * ISA cannot access memory above 16 MB.
>          */
>         else if (host->dma_addr >= 0x1000000)
> -               goto kfree;
> +               goto unmap;
>
>         host->dma = dma;
>
>         return;
>
> -kfree:
> +unmap:
>         /*
>          * If we've gotten here then there is some kind of alignment bug
>          */
> @@ -1421,6 +1423,7 @@ static void wbsd_request_dma(struct wbsd_host *host, int dma)
>                 WBSD_DMA_SIZE, DMA_BIDIRECTIONAL);
>         host->dma_addr = 0;
>
> +kfree:
>         kfree(host->dma_buffer);
>         host->dma_buffer = NULL;
>
> @@ -1434,7 +1437,7 @@ static void wbsd_request_dma(struct wbsd_host *host, int dma)
>
>  static void wbsd_release_dma(struct wbsd_host *host)
>  {
> -       if (host->dma_addr) {
> +       if (!dma_mapping_error(mmc_dev(host->mmc), host->dma_addr)) {
>                 dma_unmap_single(mmc_dev(host->mmc), host->dma_addr,
>                         WBSD_DMA_SIZE, DMA_BIDIRECTIONAL);
>         }
> --
> 2.7.4
>