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

From: Lee Jones <lee.jones@linaro.org>
To: alokc@codeaurora.org, andy.gross@linaro.org,
	david.brown@linaro.org, wsa+renesas@sang-engineering.com,
	bjorn.andersson@linaro.org, linus.walleij@linaro.org,
	balbi@kernel.org, gregkh@linuxfoundation.org
Cc: 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,
	Lee Jones <lee.jones@linaro.org>
Subject: [PATCH 8/8] usb: dwc3: qcom: Improve error handling
Date: Wed,  5 Jun 2019 12:43:02 +0100	[thread overview]
Message-ID: <20190605114302.22509-8-lee.jones@linaro.org> (raw)
In-Reply-To: <20190605114302.22509-1-lee.jones@linaro.org>

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 55ba04254e38..e4dac82abd7d 100644
--- a/drivers/usb/dwc3/dwc3-qcom.c
+++ b/drivers/usb/dwc3/dwc3-qcom.c
@@ -409,6 +409,9 @@ static int dwc3_qcom_clk_init(struct dwc3_qcom *qcom, int count)
 	if (!np || !count)
 		return 0;
 
+	if (count < 0)
+		return count;
+
 	qcom->num_clocks = count;
 
 	qcom->clks = devm_kcalloc(dev, qcom->num_clocks,
-- 
2.17.1

