Re: [PATCH 8/8] usb: dwc3: qcom: Improve error handling

From: Bjorn Andersson <bjorn.andersson@linaro.org>
To: Lee Jones <lee.jones@linaro.org>
Cc: alokc@codeaurora.org, kramasub@codeaurora.org,
	andy.gross@linaro.org, david.brown@linaro.org,
	wsa+renesas@sang-engineering.com, linus.walleij@linaro.org,
	balbi@kernel.org, gregkh@linuxfoundation.org,
	linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org, jlhugo@gmail.com,
	linux-i2c@vger.kernel.org, linux-arm-msm@vger.kernel.org,
	linux-gpio@vger.kernel.org, linux-usb@vger.kernel.org
Subject: Re: [PATCH 8/8] usb: dwc3: qcom: Improve error handling
Date: Wed, 5 Jun 2019 00:03:30 -0700	[thread overview]
Message-ID: <20190605070330.GO22737@tuxbook-pro> (raw)
In-Reply-To: <20190604104455.8877-8-lee.jones@linaro.org>

On Tue 04 Jun 03:44 PDT 2019, Lee Jones wrote:

> dwc3_qcom_clk_init() is called with of_count_phandle_with_args() as an
> argument.  If of_count_phandle_with_args() returns an error, the number
> of clocks will be a negative value and will lead to undefined behaviour.
> 
> Ensure we check for an error before attempting to blindly use the value.
> 
> Signed-off-by: Lee Jones <lee.jones@linaro.org>

Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>

> ---
>  drivers/usb/dwc3/dwc3-qcom.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/drivers/usb/dwc3/dwc3-qcom.c b/drivers/usb/dwc3/dwc3-qcom.c
> index f21fdd6cdd1a..633482926497 100644
> --- a/drivers/usb/dwc3/dwc3-qcom.c
> +++ b/drivers/usb/dwc3/dwc3-qcom.c
> @@ -419,6 +419,9 @@ static int dwc3_qcom_clk_init(struct dwc3_qcom *qcom, int count)
>  	if (!count || ACPI_HANDLE(dev))
>  		return 0;
>  
> +	if (count < 0)
> +		return count;
> +
>  	qcom->clks = devm_kcalloc(dev, qcom->num_clocks,
>  				  sizeof(struct clk *), GFP_KERNEL);
>  	if (!qcom->clks)
> -- 
> 2.17.1
> 