2016-11-11 21:42:57

by Alexey Khoroshilov

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

wbsd_request_dma() does not check for dma mapping errors.

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

Signed-off-by: Alexey Khoroshilov <[email protected]>
---
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

2016-11-18 14:29:36

by Ulf Hansson

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

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

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
>