[PATCH] wifi: iwlegacy: Use kcalloc() instead of kzalloc()

[PATCH] wifi: iwlegacy: Use kcalloc() instead of kzalloc()

[Erick Archer]

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 kcalloc() function instead of the argument
size * count in the kzalloc() function.

Also, it is preferred to use sizeof(*pointer) instead of sizeof(type)
due to the type of the variable can change and one needs not change the
former (unlike the latter).

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 <erick.archer@gmx.com>
---
 drivers/net/wireless/intel/iwlegacy/common.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/drivers/net/wireless/intel/iwlegacy/common.c b/drivers/net/wireless/intel/iwlegacy/common.c
index 17570d62c896..9d33a66a49b5 100644
--- a/drivers/net/wireless/intel/iwlegacy/common.c
+++ b/drivers/net/wireless/intel/iwlegacy/common.c
@@ -3438,9 +3438,7 @@ il_init_geos(struct il_priv *il)
 	if (!channels)
 		return -ENOMEM;

-	rates =
-	    kzalloc((sizeof(struct ieee80211_rate) * RATE_COUNT_LEGACY),
-		    GFP_KERNEL);
+	rates = kcalloc(RATE_COUNT_LEGACY, sizeof(*rates), GFP_KERNEL);
 	if (!rates) {
 		kfree(channels);
 		return -ENOMEM;
--
2.25.1

Re: [PATCH] wifi: iwlegacy: Use kcalloc() instead of kzalloc()

[Gustavo A. R. Silva]

On 1/19/24 11:16, 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 kcalloc() function instead of the argument
> size * count in the kzalloc() function.
> 
> Also, it is preferred to use sizeof(*pointer) instead of sizeof(type)
> due to the type of the variable can change and one needs not change the
> former (unlike the latter).
> 
> 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 <erick.archer@gmx.com>

Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org>

Thanks!
-- 
Gustavo

> ---
>   drivers/net/wireless/intel/iwlegacy/common.c | 4 +---
>   1 file changed, 1 insertion(+), 3 deletions(-)
> 
> diff --git a/drivers/net/wireless/intel/iwlegacy/common.c b/drivers/net/wireless/intel/iwlegacy/common.c
> index 17570d62c896..9d33a66a49b5 100644
> --- a/drivers/net/wireless/intel/iwlegacy/common.c
> +++ b/drivers/net/wireless/intel/iwlegacy/common.c
> @@ -3438,9 +3438,7 @@ il_init_geos(struct il_priv *il)
>   	if (!channels)
>   		return -ENOMEM;
> 
> -	rates =
> -	    kzalloc((sizeof(struct ieee80211_rate) * RATE_COUNT_LEGACY),
> -		    GFP_KERNEL);
> +	rates = kcalloc(RATE_COUNT_LEGACY, sizeof(*rates), GFP_KERNEL);
>   	if (!rates) {
>   		kfree(channels);
>   		return -ENOMEM;
> --
> 2.25.1
> 
> 

Re: [PATCH] wifi: iwlegacy: Use kcalloc() instead of kzalloc()

[Stanislaw Gruszka]

On Fri, Jan 19, 2024 at 06:16:55PM +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 kcalloc() function instead of the argument
> size * count in the kzalloc() function.
> 
> Also, it is preferred to use sizeof(*pointer) instead of sizeof(type)
> due to the type of the variable can change and one needs not change the
> former (unlike the latter).
> 
> 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 <erick.archer@gmx.com>

Acked-by: Stanislaw Gruszka <stf_xl@wp.pl>

Re: [PATCH] wifi: iwlegacy: Use kcalloc() instead of kzalloc()

[Kalle Valo]

Erick Archer <erick.archer@gmx.com> 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 kcalloc() function instead of the argument
> size * count in the kzalloc() function.
> 
> Also, it is preferred to use sizeof(*pointer) instead of sizeof(type)
> due to the type of the variable can change and one needs not change the
> former (unlike the latter).
> 
> 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 <erick.archer@gmx.com>
> Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org>
> Acked-by: Stanislaw Gruszka <stf_xl@wp.pl>

Patch applied to wireless-next.git, thanks.

acf868ff60b1 wifi: iwlegacy: Use kcalloc() instead of kzalloc()

-- 
https://patchwork.kernel.org/project/linux-wireless/patch/20240119171655.7740-1-erick.archer@gmx.com/

https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches