2022-11-30 10:40:33

by Yi Yang

Subject: [PATCH] usb: fotg210-udc: fix potential memory leak in fotg210_udc_probe()

In fotg210_udc_probe(), if devm_clk_get() or clk_prepare_enable()
fails, 'fotg210' will not be freed, which will lead to a memory leak.
Fix it by moving kfree() to a proper location.

Fixes: 718a38d092ec ("fotg210-udc: Handle PCLK")
Signed-off-by: Yi Yang <[email protected]>
---
drivers/usb/fotg210/fotg210-udc.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/drivers/usb/fotg210/fotg210-udc.c b/drivers/usb/fotg210/fotg210-udc.c
index b9ea6c6d931c..a366d69c1818 100644
--- a/drivers/usb/fotg210/fotg210-udc.c
+++ b/drivers/usb/fotg210/fotg210-udc.c
@@ -1178,7 +1178,7 @@ int fotg210_udc_probe(struct platform_device *pdev)
ret = clk_prepare_enable(fotg210->pclk);
if (ret) {
dev_err(dev, "failed to enable PCLK\n");
- return ret;
+ goto err;
}
} else if (PTR_ERR(fotg210->pclk) == -EPROBE_DEFER) {
/*
@@ -1302,8 +1302,7 @@ int fotg210_udc_probe(struct platform_device *pdev)
if (!IS_ERR(fotg210->pclk))
clk_disable_unprepare(fotg210->pclk);

- kfree(fotg210);
-
err:
+ kfree(fotg210);
return ret;
}
--
2.17.1

2022-12-01 10:38:32

by Andrzej Pietrasiewicz

Subject: Re: [PATCH] usb: fotg210-udc: fix potential memory leak in fotg210_udc_probe()

Hi Yi Yang,

You can make your patch also simplify the code.

Earlier, there's

ret = -ENOMEM;

/* initialize udc */
fotg210 = kzalloc(sizeof(struct fotg210_udc), GFP_KERNEL);
if (fotg210 == NULL)
goto err;

and the code at the "err" label before your changes merely returns "ret".
Instead of "goto err" return -ENOMEM can be used. This, in turn,
eliminates the ret = -ENOMEM assignment. Furthermore, after applying your
patch as-is, the said "goto err;" will result with kfree(NULL) which is safe,
but unnecessary.

If you include the above changes you can add my

Reviewed-by: Andrzej Pietrasiewicz <[email protected]>

W dniu 30.11.2022 o 11:12, Yi Yang pisze:
> In fotg210_udc_probe(), if devm_clk_get() or clk_prepare_enable()
> fails, 'fotg210' will not be freed, which will lead to a memory leak.
> Fix it by moving kfree() to a proper location.
>
> Fixes: 718a38d092ec ("fotg210-udc: Handle PCLK")
> Signed-off-by: Yi Yang <[email protected]>
> ---
> drivers/usb/fotg210/fotg210-udc.c | 5 ++---
> 1 file changed, 2 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/usb/fotg210/fotg210-udc.c b/drivers/usb/fotg210/fotg210-udc.c
> index b9ea6c6d931c..a366d69c1818 100644
> --- a/drivers/usb/fotg210/fotg210-udc.c
> +++ b/drivers/usb/fotg210/fotg210-udc.c
> @@ -1178,7 +1178,7 @@ int fotg210_udc_probe(struct platform_device *pdev)
> ret = clk_prepare_enable(fotg210->pclk);
> if (ret) {
> dev_err(dev, "failed to enable PCLK\n");
> - return ret;
> + goto err;
> }
> } else if (PTR_ERR(fotg210->pclk) == -EPROBE_DEFER) {
> /*
> @@ -1302,8 +1302,7 @@ int fotg210_udc_probe(struct platform_device *pdev)
> if (!IS_ERR(fotg210->pclk))
> clk_disable_unprepare(fotg210->pclk);
>
> - kfree(fotg210);
> -
> err:
> + kfree(fotg210);
> return ret;
> }

2022-12-04 18:31:19

by Linus Walleij

Subject: Re: [PATCH] usb: fotg210-udc: fix potential memory leak in fotg210_udc_probe()

On Wed, Nov 30, 2022 at 11:15 AM Yi Yang <[email protected]> wrote:

> In fotg210_udc_probe(), if devm_clk_get() or clk_prepare_enable()
> fails, 'fotg210' will not be freed, which will lead to a memory leak.
> Fix it by moving kfree() to a proper location.
>
> Fixes: 718a38d092ec ("fotg210-udc: Handle PCLK")
> Signed-off-by: Yi Yang <[email protected]>

Acked-by: Linus Walleij <[email protected]>

Yours,
Linus Walleij