2015-12-17 23:32:35

by Måns Rullgård

Subject: [PATCH] dmaengine: dw: fix potential memory leak in dw_dma_parse_dt()

If the "dma-channels" DT property is missing, the dw_dma_parse_dt()
function return NULL, but not before allocating memory for a struct
dw_dma_platform_data through devres. If the device supports parameter
detection, the probe still succeeds and the allocated memory is not
released until the device is removed.

Fix this by deferring the allocation until after checking the
"dma-channels" property.

Signed-off-by: Mans Rullgard <[email protected]>
---
This has only been compile-tested as I have no suitable hardware.
---
drivers/dma/dw/platform.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/dma/dw/platform.c b/drivers/dma/dw/platform.c
index 68a4815..5a417bb 100644
--- a/drivers/dma/dw/platform.c
+++ b/drivers/dma/dw/platform.c
@@ -103,18 +103,21 @@ dw_dma_parse_dt(struct platform_device *pdev)
struct device_node *np = pdev->dev.of_node;
struct dw_dma_platform_data *pdata;
u32 tmp, arr[DW_DMA_MAX_NR_MASTERS];
+ u32 nr_channels;

if (!np) {
dev_err(&pdev->dev, "Missing DT data\n");
return NULL;
}

+ if (of_property_read_u32(np, "dma-channels", &nr_channels))
+ return NULL;
+
pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
if (!pdata)
return NULL;

- if (of_property_read_u32(np, "dma-channels", &pdata->nr_channels))
- return NULL;
+ pdata->nr_channels = nr_channels;

if (of_property_read_bool(np, "is_private"))
pdata->is_private = true;
--
2.6.3

2015-12-18 01:59:08

by Viresh Kumar

Subject: Re: [PATCH] dmaengine: dw: fix potential memory leak in dw_dma_parse_dt()

On 17-12-15, 23:30, Mans Rullgard wrote:
> If the "dma-channels" DT property is missing, the dw_dma_parse_dt()
> function return NULL, but not before allocating memory for a struct
> dw_dma_platform_data through devres. If the device supports parameter
> detection, the probe still succeeds and the allocated memory is not
> released until the device is removed.
>
> Fix this by deferring the allocation until after checking the
> "dma-channels" property.
>
> Signed-off-by: Mans Rullgard <[email protected]>
> ---
> This has only been compile-tested as I have no suitable hardware.
> ---
> drivers/dma/dw/platform.c | 7 +++++--
> 1 file changed, 5 insertions(+), 2 deletions(-)

Acked-by: Viresh Kumar <[email protected]>

--
viresh

2015-12-18 05:26:55

by Vinod Koul

Subject: Re: [PATCH] dmaengine: dw: fix potential memory leak in dw_dma_parse_dt()

On Thu, Dec 17, 2015 at 11:30:57PM +0000, Mans Rullgard wrote:
> If the "dma-channels" DT property is missing, the dw_dma_parse_dt()
> function return NULL, but not before allocating memory for a struct
> dw_dma_platform_data through devres. If the device supports parameter
> detection, the probe still succeeds and the allocated memory is not
> released until the device is removed.
>
> Fix this by deferring the allocation until after checking the
> "dma-channels" property.

Applied, thanks

--
~Vinod