2019-01-18 21:20:28

by Alexey Khoroshilov

Subject: [PATCH] usb: dwc3: exynos: Fix error handling of clk_prepare_enable

If clk_prepare_enable() fails in dwc3_exynos_probe(),
exynos->clks[0] is left undisabled because of usage
preincrement in while condition.

Found by Linux Driver Verification project (linuxtesting.org).

Signed-off-by: Alexey Khoroshilov <[email protected]>
Fixes: 9f2168367a0a ("usb: dwc3: exynos: Rework clock handling and prepare for new variants")
---
drivers/usb/dwc3/dwc3-exynos.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/usb/dwc3/dwc3-exynos.c b/drivers/usb/dwc3/dwc3-exynos.c
index cb7fcd7c0ad8..e7f6cff27b9a 100644
--- a/drivers/usb/dwc3/dwc3-exynos.c
+++ b/drivers/usb/dwc3/dwc3-exynos.c
@@ -78,7 +78,7 @@ static int dwc3_exynos_probe(struct platform_device *pdev)
for (i = 0; i < exynos->num_clks; i++) {
ret = clk_prepare_enable(exynos->clks[i]);
if (ret) {
- while (--i > 0)
+ while (i-- > 0)
clk_disable_unprepare(exynos->clks[i]);
return ret;
}
--
2.7.4

2019-01-21 09:59:17

by Marek Szyprowski

Subject: Re: [PATCH] usb: dwc3: exynos: Fix error handling of clk_prepare_enable

Hi Alexey,

On 2019-01-18 22:17, Alexey Khoroshilov wrote:
> If clk_prepare_enable() fails in dwc3_exynos_probe(),
> exynos->clks[0] is left undisabled because of usage
> preincrement in while condition.
>
> Found by Linux Driver Verification project (linuxtesting.org).
>
> Signed-off-by: Alexey Khoroshilov <[email protected]>
> Fixes: 9f2168367a0a ("usb: dwc3: exynos: Rework clock handling and prepare for new variants")

My fault. There is also a similar issue dwc3_exynos_resume(), so please
fix it too if possible.

> ---
> drivers/usb/dwc3/dwc3-exynos.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/usb/dwc3/dwc3-exynos.c b/drivers/usb/dwc3/dwc3-exynos.c
> index cb7fcd7c0ad8..e7f6cff27b9a 100644
> --- a/drivers/usb/dwc3/dwc3-exynos.c
> +++ b/drivers/usb/dwc3/dwc3-exynos.c
> @@ -78,7 +78,7 @@ static int dwc3_exynos_probe(struct platform_device *pdev)
> for (i = 0; i < exynos->num_clks; i++) {
> ret = clk_prepare_enable(exynos->clks[i]);
> if (ret) {
> - while (--i > 0)
> + while (i-- > 0)
> clk_disable_unprepare(exynos->clks[i]);
> return ret;
> }

Best regards
--
Marek Szyprowski, PhD
Samsung R&D Institute Poland