Re: [PATCH] bus: mhi: ep: Use kcalloc() instead of kzalloc()

[Gustavo A. R. Silva]

On 1/20/24 09:25, 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
> count * size in the 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 <erick.archer@xxxxxxx>

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

Thanks!
--
Gustavo

> ---
>   drivers/bus/mhi/ep/main.c | 5 +++--
>   1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/bus/mhi/ep/main.c b/drivers/bus/mhi/ep/main.c
> index 65fc1d738bec..8d7a4102bdb7 100644
> --- a/drivers/bus/mhi/ep/main.c
> +++ b/drivers/bus/mhi/ep/main.c
> @@ -1149,8 +1149,9 @@ int mhi_ep_power_up(struct mhi_ep_cntrl *mhi_cntrl)
>   	mhi_ep_mmio_mask_interrupts(mhi_cntrl);
>   	mhi_ep_mmio_init(mhi_cntrl);
>
> -	mhi_cntrl->mhi_event = kzalloc(mhi_cntrl->event_rings * (sizeof(*mhi_cntrl->mhi_event)),
> -					GFP_KERNEL);
> +	mhi_cntrl->mhi_event = kcalloc(mhi_cntrl->event_rings,
> +				       sizeof(*mhi_cntrl->mhi_event),
> +				       GFP_KERNEL);
>   	if (!mhi_cntrl->mhi_event)
>   		return -ENOMEM;
>
> --
> 2.25.1