diff mbox series

ice: Fix improper handling of refcount in ice_dpll_init_rclk_pins()

Message ID SY8P300MB0460FB85729319189B40576FC0BA2@SY8P300MB0460.AUSP300.PROD.OUTLOOK.COM
State Changes Requested
Headers show
Series ice: Fix improper handling of refcount in ice_dpll_init_rclk_pins() | expand

Commit Message

Gui-Dong Han Aug. 9, 2024, 5:02 a.m. UTC
This patch addresses a reference count handling issue in the
ice_dpll_init_rclk_pins() function. The function calls ice_dpll_get_pins(),
which increments the reference count of the relevant resources. However,
if the condition WARN_ON((!vsi || !vsi->netdev)) is met, the function
currently returns an error without properly releasing the resources
acquired by ice_dpll_get_pins(), leading to a reference count leak.

To resolve this, the patch introduces a goto unregister_pins; statement
when the condition is met, ensuring that the resources are correctly
released and the reference count is decremented before returning the error.
This change prevents potential memory leaks and ensures proper resource
 management within the function.

This bug was identified by an experimental static analysis tool developed
by our team. The tool specializes in analyzing reference count operations
and detecting potential issues where resources are not properly managed.
In this case, the tool flagged the missing release operation as a
potential problem, which led to the development of this patch.

Fixes: d7999f5ea64b ("ice: implement dpll interface to control cgu")
Cc: stable@vger.kernel.org
Signed-off-by: Gui-Dong Han <hanguidong02@outlook.com>
---
 drivers/net/ethernet/intel/ice/ice_dpll.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

Comments

Simon Horman Aug. 10, 2024, 9:17 a.m. UTC | #1
On Fri, Aug 09, 2024 at 01:02:15PM +0800, Gui-Dong Han wrote:
> This patch addresses a reference count handling issue in the
> ice_dpll_init_rclk_pins() function. The function calls ice_dpll_get_pins(),
> which increments the reference count of the relevant resources. However,
> if the condition WARN_ON((!vsi || !vsi->netdev)) is met, the function
> currently returns an error without properly releasing the resources
> acquired by ice_dpll_get_pins(), leading to a reference count leak.
> 
> To resolve this, the patch introduces a goto unregister_pins; statement
> when the condition is met, ensuring that the resources are correctly
> released and the reference count is decremented before returning the error.
> This change prevents potential memory leaks and ensures proper resource
>  management within the function.
> 
> This bug was identified by an experimental static analysis tool developed
> by our team. The tool specializes in analyzing reference count operations
> and detecting potential issues where resources are not properly managed.
> In this case, the tool flagged the missing release operation as a
> potential problem, which led to the development of this patch.
> 
> Fixes: d7999f5ea64b ("ice: implement dpll interface to control cgu")
> Cc: stable@vger.kernel.org
> Signed-off-by: Gui-Dong Han <hanguidong02@outlook.com>
> ---
>  drivers/net/ethernet/intel/ice/ice_dpll.c | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/net/ethernet/intel/ice/ice_dpll.c b/drivers/net/ethernet/intel/ice/ice_dpll.c
> index e92be6f130a3..f3f204cae093 100644
> --- a/drivers/net/ethernet/intel/ice/ice_dpll.c
> +++ b/drivers/net/ethernet/intel/ice/ice_dpll.c
> @@ -1641,8 +1641,10 @@ ice_dpll_init_rclk_pins(struct ice_pf *pf, struct ice_dpll_pin *pin,
>  		if (ret)
>  			goto unregister_pins;
>  	}
> -	if (WARN_ON((!vsi || !vsi->netdev)))
> -		return -EINVAL;
> +	if (WARN_ON((!vsi || !vsi->netdev))) {
> +		ret = -EINVAL;
> +		goto unregister_pins;
> +	}

Hi,

I wonder if it would make sense to move the check to the
top of the function. It seems to be more of a verification
of state at the time the function is run than anything else.

Doing so would avoid the need to handle unwind in this case.

>  	dpll_netdev_pin_set(vsi->netdev, pf->dplls.rclk.pin);
>  
>  	return 0;
> -- 
> 2.25.1
> 
>
diff mbox series

Patch

diff --git a/drivers/net/ethernet/intel/ice/ice_dpll.c b/drivers/net/ethernet/intel/ice/ice_dpll.c
index e92be6f130a3..f3f204cae093 100644
--- a/drivers/net/ethernet/intel/ice/ice_dpll.c
+++ b/drivers/net/ethernet/intel/ice/ice_dpll.c
@@ -1641,8 +1641,10 @@  ice_dpll_init_rclk_pins(struct ice_pf *pf, struct ice_dpll_pin *pin,
 		if (ret)
 			goto unregister_pins;
 	}
-	if (WARN_ON((!vsi || !vsi->netdev)))
-		return -EINVAL;
+	if (WARN_ON((!vsi || !vsi->netdev))) {
+		ret = -EINVAL;
+		goto unregister_pins;
+	}
 	dpll_netdev_pin_set(vsi->netdev, pf->dplls.rclk.pin);
 
 	return 0;