Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org B220360736
Subject: Re: [PATCH] spi: oc-tiny: fix negative loop bound error on for loop
To:     Colin King <colin.king@canonical.com>,
        Mark Brown <broonie@kernel.org>, linux-spi@vger.kernel.org
Cc:     kernel-janitors@vger.kernel.org, linux-kernel@vger.kernel.org
References: <20190330212300.11675-1-colin.king@canonical.com>
From:   Mukesh Ojha <mojha@codeaurora.org>
Message-ID: <88c53375-5727-c865-05ba-829b6e7d5128@codeaurora.org>
Date:   Sun, 31 Mar 2019 14:54:16 +0530
User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:60.0) Gecko/20100101
 Thunderbird/60.6.1
MIME-Version: 1.0
In-Reply-To: <20190330212300.11675-1-colin.king@canonical.com>
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Transfer-Encoding: 7bit
Content-Language: en-US
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk


On 3/31/2019 2:53 AM, Colin King wrote:
> From: Colin Ian King <colin.king@canonical.com>
>
> Currently the for-loop using an unsigned int for the loop counter
> which is problematic when comparing it to the signed int
> gt->gpio_cs_count.  This is an issue because if the signed int is
> negative (for example, the call to of_gpio_count failed) then
> the negative loop bound is implicitly cast to an unsigned int on
> the comparison to loop counter i and will yield a very large value,
> eventually causing an array bounds overflow on hw->gpio_cs.
>
> Fix this by simply making the loop counter i a signed int;
>
> Fixes: ca632f556697 ("spi: reorganize drivers")
> Signed-off-by: Colin Ian King <colin.king@canonical.com>
> ---
>   drivers/spi/spi-oc-tiny.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/spi/spi-oc-tiny.c b/drivers/spi/spi-oc-tiny.c
> index 085f580be7ec..81f74b938dc9 100644
> --- a/drivers/spi/spi-oc-tiny.c
> +++ b/drivers/spi/spi-oc-tiny.c
> @@ -206,7 +206,7 @@ static int tiny_spi_of_probe(struct platform_device *pdev)
>   {
>   	struct tiny_spi *hw = platform_get_drvdata(pdev);
>   	struct device_node *np = pdev->dev.of_node;
> -	unsigned int i;
> +	int i;


Same issue, here as well like your other patch. you are putting wrapper 
over a original issue by not checking the returned value.
Please fix that in both patches.


Thanks.
Mukesh

>   	u32 val;
>   
>   	if (!np)