[PATCH] dma-mapping: fix an uninitialized pointer read due to typo in argp assignment

[PATCH] dma-mapping: fix an uninitialized pointer read due to typo in argp assignment

[Colin King]

From: Colin Ian King <colin.king@canonical.com>

The assignment of argp is currently using argp as the source because of
a typo. Fix this by assigning it the value passed in arg instead.

Addresses-Coverity: ("Uninitialized pointer read")
Fixes: bfd2defed94d ("dma-mapping: add benchmark support for streaming DMA APIs")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
---
 kernel/dma/map_benchmark.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/dma/map_benchmark.c b/kernel/dma/map_benchmark.c
index ca616b664f72..e1e37603d01b 100644
--- a/kernel/dma/map_benchmark.c
+++ b/kernel/dma/map_benchmark.c
@@ -192,7 +192,7 @@ static long map_benchmark_ioctl(struct file *file, unsigned int cmd,
 		unsigned long arg)
 {
 	struct map_benchmark_data *map = file->private_data;
-	void __user *argp = (void __user *)argp;
+	void __user *argp = (void __user *)arg;
 	u64 old_dma_mask;
 
 	int ret;
-- 
2.29.2

RE: [PATCH] dma-mapping: fix an uninitialized pointer read due to typo in argp assignment

[Song Bao Hua (Barry Song)]

> -----Original Message-----
> From: Colin King [mailto:colin.king@canonical.com]
> Sent: Thursday, November 26, 2020 2:56 AM
> To: Song Bao Hua (Barry Song) <song.bao.hua@hisilicon.com>; Christoph
> Hellwig <hch@lst.de>; Marek Szyprowski <m.szyprowski@samsung.com>;
> Robin Murphy <robin.murphy@arm.com>; iommu@lists.linux-foundation.org
> Cc: kernel-janitors@vger.kernel.org; linux-kernel@vger.kernel.org
> Subject: [PATCH] dma-mapping: fix an uninitialized pointer read due to typo in
> argp assignment
> 
> From: Colin Ian King <colin.king@canonical.com>
> 
> The assignment of argp is currently using argp as the source because of
> a typo. Fix this by assigning it the value passed in arg instead.
> 
> Addresses-Coverity: ("Uninitialized pointer read")
> Fixes: bfd2defed94d ("dma-mapping: add benchmark support for streaming
> DMA APIs")
> Signed-off-by: Colin Ian King <colin.king@canonical.com>

Acked-by: Barry Song <song.bao.hua@hisilicon.com>

> ---
>  kernel/dma/map_benchmark.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/kernel/dma/map_benchmark.c b/kernel/dma/map_benchmark.c
> index ca616b664f72..e1e37603d01b 100644
> --- a/kernel/dma/map_benchmark.c
> +++ b/kernel/dma/map_benchmark.c
> @@ -192,7 +192,7 @@ static long map_benchmark_ioctl(struct file *file,
> unsigned int cmd,
>  		unsigned long arg)
>  {
>  	struct map_benchmark_data *map = file->private_data;
> -	void __user *argp = (void __user *)argp;
> +	void __user *argp = (void __user *)arg;
>  	u64 old_dma_mask;
> 
>  	int ret;
> --
> 2.29.2

Thanks
Barry

Re: [PATCH] dma-mapping: fix an uninitialized pointer read due to typo in argp assignment

[Christoph Hellwig]

Ooops, that was my edit.  I'll make sure to fold the fix into the
original commit.