2024-01-21 14:30:33

by Erick Archer

[permalink] [raw]
Subject: [PATCH] clk: hisilicon: Use devm_kcalloc() instead of devm_kzalloc()

As noted in the "Deprecated Interfaces, Language Features, Attributes,
and Conventions" documentation [1], size calculations (especially
multiplication) should not be performed in memory allocator (or similar)
function arguments due to the risk of them overflowing. This could lead
to values wrapping around and a smaller allocation being made than the
caller was expecting. Using those allocations could lead to linear
overflows of heap memory and other misbehaviors.

So, use the purpose specific devm_kcalloc() function instead of the
argument size * count in the devm_kzalloc() function.

Link: https://www.kernel.org/doc/html/next/process/deprecated.html#open-coded-arithmetic-in-allocator-arguments [1]
Link: https://github.com/KSPP/linux/issues/162
Signed-off-by: Erick Archer <[email protected]>
---
drivers/clk/hisilicon/clk-hi3559a.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/clk/hisilicon/clk-hi3559a.c b/drivers/clk/hisilicon/clk-hi3559a.c
index ff4ca0edce06..da476f940326 100644
--- a/drivers/clk/hisilicon/clk-hi3559a.c
+++ b/drivers/clk/hisilicon/clk-hi3559a.c
@@ -461,8 +461,7 @@ static void hisi_clk_register_pll(struct hi3559av100_pll_clock *clks,
struct clk_init_data init;
int i;

- p_clk = devm_kzalloc(dev, sizeof(*p_clk) * nums, GFP_KERNEL);
-
+ p_clk = devm_kcalloc(dev, nums, sizeof(*p_clk), GFP_KERNEL);
if (!p_clk)
return;

--
2.25.1



2024-01-22 07:03:53

by Uwe Kleine-König

[permalink] [raw]
Subject: Re: [PATCH] clk: hisilicon: Use devm_kcalloc() instead of devm_kzalloc()

On Sun, Jan 21, 2024 at 03:29:46PM +0100, Erick Archer wrote:
> As noted in the "Deprecated Interfaces, Language Features, Attributes,
> and Conventions" documentation [1], size calculations (especially
> multiplication) should not be performed in memory allocator (or similar)
> function arguments due to the risk of them overflowing. This could lead
> to values wrapping around and a smaller allocation being made than the
> caller was expecting. Using those allocations could lead to linear
> overflows of heap memory and other misbehaviors.
>
> So, use the purpose specific devm_kcalloc() function instead of the
> argument size * count in the devm_kzalloc() function.
>
> Link: https://www.kernel.org/doc/html/next/process/deprecated.html#open-coded-arithmetic-in-allocator-arguments [1]
> Link: https://github.com/KSPP/linux/issues/162
> Signed-off-by: Erick Archer <[email protected]>
> ---
> drivers/clk/hisilicon/clk-hi3559a.c | 3 +--
> 1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/drivers/clk/hisilicon/clk-hi3559a.c b/drivers/clk/hisilicon/clk-hi3559a.c
> index ff4ca0edce06..da476f940326 100644
> --- a/drivers/clk/hisilicon/clk-hi3559a.c
> +++ b/drivers/clk/hisilicon/clk-hi3559a.c
> @@ -461,8 +461,7 @@ static void hisi_clk_register_pll(struct hi3559av100_pll_clock *clks,
> struct clk_init_data init;
> int i;
>
> - p_clk = devm_kzalloc(dev, sizeof(*p_clk) * nums, GFP_KERNEL);
> -
> + p_clk = devm_kcalloc(dev, nums, sizeof(*p_clk), GFP_KERNEL);
> if (!p_clk)
> return;

Looks good,

Reviewed-by: Uwe Kleine-K?nig <[email protected]>

My first impulse was to ask why hisi_clk_register_pll doesn't return an
error if the allocation fails, but I guess that happens so early that no
sensible error handling is possible?

Best regards
Uwe

--
Pengutronix e.K. | Uwe Kleine-K?nig |
Industrial Linux Solutions | https://www.pengutronix.de/ |


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2024-01-22 18:58:33

by Gustavo A. R. Silva

[permalink] [raw]
Subject: Re: [PATCH] clk: hisilicon: Use devm_kcalloc() instead of devm_kzalloc()



On 1/21/24 08:29, Erick Archer wrote:
> As noted in the "Deprecated Interfaces, Language Features, Attributes,
> and Conventions" documentation [1], size calculations (especially
> multiplication) should not be performed in memory allocator (or similar)
> function arguments due to the risk of them overflowing. This could lead
> to values wrapping around and a smaller allocation being made than the
> caller was expecting. Using those allocations could lead to linear
> overflows of heap memory and other misbehaviors.
>
> So, use the purpose specific devm_kcalloc() function instead of the
> argument size * count in the devm_kzalloc() function.
>
> Link: https://www.kernel.org/doc/html/next/process/deprecated.html#open-coded-arithmetic-in-allocator-arguments [1]
> Link: https://github.com/KSPP/linux/issues/162
> Signed-off-by: Erick Archer <[email protected]>

Reviewed-by: Gustavo A. R. Silva <[email protected]>

Thanks!
--
Gustavo

> ---
> drivers/clk/hisilicon/clk-hi3559a.c | 3 +--
> 1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/drivers/clk/hisilicon/clk-hi3559a.c b/drivers/clk/hisilicon/clk-hi3559a.c
> index ff4ca0edce06..da476f940326 100644
> --- a/drivers/clk/hisilicon/clk-hi3559a.c
> +++ b/drivers/clk/hisilicon/clk-hi3559a.c
> @@ -461,8 +461,7 @@ static void hisi_clk_register_pll(struct hi3559av100_pll_clock *clks,
> struct clk_init_data init;
> int i;
>
> - p_clk = devm_kzalloc(dev, sizeof(*p_clk) * nums, GFP_KERNEL);
> -
> + p_clk = devm_kcalloc(dev, nums, sizeof(*p_clk), GFP_KERNEL);
> if (!p_clk)
> return;
>
> --
> 2.25.1
>
>

2024-02-22 04:27:44

by Stephen Boyd

[permalink] [raw]
Subject: Re: [PATCH] clk: hisilicon: Use devm_kcalloc() instead of devm_kzalloc()

Quoting Erick Archer (2024-01-21 06:29:46)
> As noted in the "Deprecated Interfaces, Language Features, Attributes,
> and Conventions" documentation [1], size calculations (especially
> multiplication) should not be performed in memory allocator (or similar)
> function arguments due to the risk of them overflowing. This could lead
> to values wrapping around and a smaller allocation being made than the
> caller was expecting. Using those allocations could lead to linear
> overflows of heap memory and other misbehaviors.
>
> So, use the purpose specific devm_kcalloc() function instead of the
> argument size * count in the devm_kzalloc() function.
>
> Link: https://www.kernel.org/doc/html/next/process/deprecated.html#open-coded-arithmetic-in-allocator-arguments [1]
> Link: https://github.com/KSPP/linux/issues/162
> Signed-off-by: Erick Archer <[email protected]>
> ---

Applied to clk-next