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Message-ID: <91e87233-3a10-43d6-b850-9cac083913e0@embeddedor.com>
Date: Mon, 22 Jan 2024 10:45:52 -0600
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Subject: Re: [PATCH] accel/habanalabs: use kcalloc() instead of kzalloc()
Content-Language: en-US
To: Erick Archer <erick.archer@gmx.com>, Oded Gabbay <ogabbay@kernel.org>,
 Marco Pagani <marpagan@redhat.com>,
 "Gustavo A. R. Silva" <gustavoars@kernel.org>
Cc: dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org,
 linux-hardening@vger.kernel.org
References: <20240120151028.11092-1-erick.archer@gmx.com>
From: "Gustavo A. R. Silva" <gustavo@embeddedor.com>
In-Reply-To: <20240120151028.11092-1-erick.archer@gmx.com>
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On 1/20/24 09:10, 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.
> 
> 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/accel/habanalabs/common/mmu/mmu_v1.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/accel/habanalabs/common/mmu/mmu_v1.c b/drivers/accel/habanalabs/common/mmu/mmu_v1.c
> index d925dc4dd097..e3d42cfead27 100644
> --- a/drivers/accel/habanalabs/common/mmu/mmu_v1.c
> +++ b/drivers/accel/habanalabs/common/mmu/mmu_v1.c
> @@ -232,7 +232,7 @@ static int dram_default_mapping_init(struct hl_ctx *ctx)
>   	/* add hop1 and hop2 */
>   	total_hops = num_of_hop3 + 2;
> 
> -	ctx->dram_default_hops = kzalloc(HL_PTE_SIZE * total_hops,  GFP_KERNEL);
> +	ctx->dram_default_hops = kcalloc(total_hops, HL_PTE_SIZE,  GFP_KERNEL);
>   	if (!ctx->dram_default_hops)
>   		return -ENOMEM;
> 
> --
> 2.25.1
> 
>