[v3] net: pds_core: Fix possible double free in error handling path

[PATCH net V3] net: pds_core: Fix possible double free in error handling path

Posted by Yongzhi Liu 1 year, 11 months ago

When auxiliary_device_add() returns error and then calls
auxiliary_device_uninit(), Callback function pdsc_auxbus_dev_release
calls kfree(padev) to free memory. We shouldn't call kfree(padev)
again in the error handling path.

Fix this by cleaning up the redundant kfree() and putting
the error handling back to where the errors happened.

Fixes: 4569cce43bc6 ("pds_core: add auxiliary_bus devices")
Signed-off-by: Yongzhi Liu <hyperlyzcs@gmail.com>
---
 drivers/net/ethernet/amd/pds_core/auxbus.c | 12 ++++--------
 1 file changed, 4 insertions(+), 8 deletions(-)

diff --git a/drivers/net/ethernet/amd/pds_core/auxbus.c b/drivers/net/ethernet/amd/pds_core/auxbus.c
index 11c23a7f3172..fd1a5149c003 100644
--- a/drivers/net/ethernet/amd/pds_core/auxbus.c
+++ b/drivers/net/ethernet/amd/pds_core/auxbus.c
@@ -160,23 +160,19 @@ static struct pds_auxiliary_dev *pdsc_auxbus_dev_register(struct pdsc *cf,
 	if (err < 0) {
 		dev_warn(cf->dev, "auxiliary_device_init of %s failed: %pe\n",
 			 name, ERR_PTR(err));
-		goto err_out;
+		kfree(padev);
+		return ERR_PTR(err);
 	}
 
 	err = auxiliary_device_add(aux_dev);
 	if (err) {
 		dev_warn(cf->dev, "auxiliary_device_add of %s failed: %pe\n",
 			 name, ERR_PTR(err));
-		goto err_out_uninit;
+		auxiliary_device_uninit(aux_dev);
+		return ERR_PTR(err);
 	}
 
 	return padev;
-
-err_out_uninit:
-	auxiliary_device_uninit(aux_dev);
-err_out:
-	kfree(padev);
-	return ERR_PTR(err);
 }
 
 int pdsc_auxbus_dev_del(struct pdsc *cf, struct pdsc *pf)
-- 
2.36.1

Re: [PATCH net V3] net: pds_core: Fix possible double free in error handling path

Posted by Nelson, Shannon 1 year, 11 months ago

On 3/6/2024 2:57 AM, Yongzhi Liu wrote:
> When auxiliary_device_add() returns error and then calls
> auxiliary_device_uninit(), Callback function pdsc_auxbus_dev_release
> calls kfree(padev) to free memory. We shouldn't call kfree(padev)
> again in the error handling path.
> 
> Fix this by cleaning up the redundant kfree() and putting
> the error handling back to where the errors happened.
> 
> Fixes: 4569cce43bc6 ("pds_core: add auxiliary_bus devices")
> Signed-off-by: Yongzhi Liu <hyperlyzcs@gmail.com>


Reviewed-by: Shannon Nelson <shannon.nelson@amd.com>

> ---
>   drivers/net/ethernet/amd/pds_core/auxbus.c | 12 ++++--------
>   1 file changed, 4 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/net/ethernet/amd/pds_core/auxbus.c b/drivers/net/ethernet/amd/pds_core/auxbus.c
> index 11c23a7f3172..fd1a5149c003 100644
> --- a/drivers/net/ethernet/amd/pds_core/auxbus.c
> +++ b/drivers/net/ethernet/amd/pds_core/auxbus.c
> @@ -160,23 +160,19 @@ static struct pds_auxiliary_dev *pdsc_auxbus_dev_register(struct pdsc *cf,
>          if (err < 0) {
>                  dev_warn(cf->dev, "auxiliary_device_init of %s failed: %pe\n",
>                           name, ERR_PTR(err));
> -               goto err_out;
> +               kfree(padev);
> +               return ERR_PTR(err);
>          }
> 
>          err = auxiliary_device_add(aux_dev);
>          if (err) {
>                  dev_warn(cf->dev, "auxiliary_device_add of %s failed: %pe\n",
>                           name, ERR_PTR(err));
> -               goto err_out_uninit;
> +               auxiliary_device_uninit(aux_dev);
> +               return ERR_PTR(err);
>          }
> 
>          return padev;
> -
> -err_out_uninit:
> -       auxiliary_device_uninit(aux_dev);
> -err_out:
> -       kfree(padev);
> -       return ERR_PTR(err);
>   }
> 
>   int pdsc_auxbus_dev_del(struct pdsc *cf, struct pdsc *pf)
> --
> 2.36.1
>

Re: [PATCH net V3] net: pds_core: Fix possible double free in error handling path

Posted by Wojciech Drewek 1 year, 11 months ago


On 06.03.2024 11:57, Yongzhi Liu wrote:
> When auxiliary_device_add() returns error and then calls
> auxiliary_device_uninit(), Callback function pdsc_auxbus_dev_release
> calls kfree(padev) to free memory. We shouldn't call kfree(padev)
> again in the error handling path.
> 
> Fix this by cleaning up the redundant kfree() and putting
> the error handling back to where the errors happened.
> 
> Fixes: 4569cce43bc6 ("pds_core: add auxiliary_bus devices")
> Signed-off-by: Yongzhi Liu <hyperlyzcs@gmail.com>
> ---

Reviewed-by: Wojciech Drewek <wojciech.drewek@intel.com>

>  drivers/net/ethernet/amd/pds_core/auxbus.c | 12 ++++--------
>  1 file changed, 4 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/net/ethernet/amd/pds_core/auxbus.c b/drivers/net/ethernet/amd/pds_core/auxbus.c
> index 11c23a7f3172..fd1a5149c003 100644
> --- a/drivers/net/ethernet/amd/pds_core/auxbus.c
> +++ b/drivers/net/ethernet/amd/pds_core/auxbus.c
> @@ -160,23 +160,19 @@ static struct pds_auxiliary_dev *pdsc_auxbus_dev_register(struct pdsc *cf,
>  	if (err < 0) {
>  		dev_warn(cf->dev, "auxiliary_device_init of %s failed: %pe\n",
>  			 name, ERR_PTR(err));
> -		goto err_out;
> +		kfree(padev);
> +		return ERR_PTR(err);
>  	}
>  
>  	err = auxiliary_device_add(aux_dev);
>  	if (err) {
>  		dev_warn(cf->dev, "auxiliary_device_add of %s failed: %pe\n",
>  			 name, ERR_PTR(err));
> -		goto err_out_uninit;
> +		auxiliary_device_uninit(aux_dev);
> +		return ERR_PTR(err);
>  	}
>  
>  	return padev;
> -
> -err_out_uninit:
> -	auxiliary_device_uninit(aux_dev);
> -err_out:
> -	kfree(padev);
> -	return ERR_PTR(err);
>  }
>  
>  int pdsc_auxbus_dev_del(struct pdsc *cf, struct pdsc *pf)