usb: ehci-hcd: fix call balance of clocks handling routines

[PATCH] usb: ehci-hcd: fix call balance of clocks handling routines

Posted by Vitalii Mordan 2 days, 15 hours ago

If the clocks priv->iclk and priv->fclk were not enabled in ehci_hcd_sh_probe,
they should not be disabled in any path.

Conversely, if they was enabled in ehci_hcd_sh_probe, they must be disabled
in all error paths to ensure proper cleanup.

Found by Linux Verification Center (linuxtesting.org) with Klever.

Fixes: 63c845522263 ("usb: ehci-hcd: Add support for SuperH EHCI.")
Cc: stable@vger.kernel.org # ff30bd6a6618: sh: clk: Fix clk_enable() to return 0 on NULL clk
Signed-off-by: Vitalii Mordan <mordan@ispras.ru>
---
 drivers/usb/host/ehci-sh.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/host/ehci-sh.c b/drivers/usb/host/ehci-sh.c
index d31d9506e41a..77460aac6dbd 100644
--- a/drivers/usb/host/ehci-sh.c
+++ b/drivers/usb/host/ehci-sh.c
@@ -119,8 +119,12 @@ static int ehci_hcd_sh_probe(struct platform_device *pdev)
 	if (IS_ERR(priv->iclk))
 		priv->iclk = NULL;
 
-	clk_enable(priv->fclk);
-	clk_enable(priv->iclk);
+	ret = clk_enable(priv->fclk);
+	if (ret)
+		goto fail_request_resource;
+	ret = clk_enable(priv->iclk);
+	if (ret)
+		goto fail_iclk;
 
 	ret = usb_add_hcd(hcd, irq, IRQF_SHARED);
 	if (ret != 0) {
@@ -136,6 +140,7 @@ static int ehci_hcd_sh_probe(struct platform_device *pdev)
 
 fail_add_hcd:
 	clk_disable(priv->iclk);
+fail_iclk:
 	clk_disable(priv->fclk);
 
 fail_request_resource:
-- 
2.25.1

Re: [PATCH] usb: ehci-hcd: fix call balance of clocks handling routines

Posted by Alan Stern 2 days, 12 hours ago

On Thu, Nov 21, 2024 at 02:47:00PM +0300, Vitalii Mordan wrote:
> If the clocks priv->iclk and priv->fclk were not enabled in ehci_hcd_sh_probe,
> they should not be disabled in any path.
> 
> Conversely, if they was enabled in ehci_hcd_sh_probe, they must be disabled
> in all error paths to ensure proper cleanup.
> 
> Found by Linux Verification Center (linuxtesting.org) with Klever.
> 
> Fixes: 63c845522263 ("usb: ehci-hcd: Add support for SuperH EHCI.")
> Cc: stable@vger.kernel.org # ff30bd6a6618: sh: clk: Fix clk_enable() to return 0 on NULL clk
> Signed-off-by: Vitalii Mordan <mordan@ispras.ru>
> ---

Reviewed-by: Alan Stern <stern@rowland.harvard.edu>

>  drivers/usb/host/ehci-sh.c | 9 +++++++--
>  1 file changed, 7 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/usb/host/ehci-sh.c b/drivers/usb/host/ehci-sh.c
> index d31d9506e41a..77460aac6dbd 100644
> --- a/drivers/usb/host/ehci-sh.c
> +++ b/drivers/usb/host/ehci-sh.c
> @@ -119,8 +119,12 @@ static int ehci_hcd_sh_probe(struct platform_device *pdev)
>  	if (IS_ERR(priv->iclk))
>  		priv->iclk = NULL;
>  
> -	clk_enable(priv->fclk);
> -	clk_enable(priv->iclk);
> +	ret = clk_enable(priv->fclk);
> +	if (ret)
> +		goto fail_request_resource;
> +	ret = clk_enable(priv->iclk);
> +	if (ret)
> +		goto fail_iclk;
>  
>  	ret = usb_add_hcd(hcd, irq, IRQF_SHARED);
>  	if (ret != 0) {
> @@ -136,6 +140,7 @@ static int ehci_hcd_sh_probe(struct platform_device *pdev)
>  
>  fail_add_hcd:
>  	clk_disable(priv->iclk);
> +fail_iclk:
>  	clk_disable(priv->fclk);
>  
>  fail_request_resource:
> -- 
> 2.25.1
>