[PATCH net] net: ethernet: mtk_ppe: Fix rhashtable leak in mtk_ppe_init error paths

[PATCH net] net: ethernet: mtk_ppe: Fix rhashtable leak in mtk_ppe_init error paths

[Wayen Yan]

In mtk_ppe_init(), when accounting is enabled, the error paths for
dmam_alloc_coherent(mib) and devm_kzalloc(acct) failures return NULL
directly, bypassing the err_free_l2_flows label that destroys the
rhashtable initialized earlier.

While this leak only occurs during probe (not runtime) and the leaked
memory is minimal (an empty rhash table), fixing it ensures proper
error path cleanup consistency.

Fix by changing the two return NULL statements to goto err_free_l2_flows.

Fixes: 603ea5e7ffa7 ("net: ethernet: mtk_eth_soc: fix memory leak in error path")
Signed-off-by: Wayen Yan <win847@gmail.com>
---
 drivers/net/ethernet/mediatek/mtk_ppe.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/mediatek/mtk_ppe.c b/drivers/net/ethernet/mediatek/mtk_ppe.c
index 18279e2a70..8451dc3fd0 100644
--- a/drivers/net/ethernet/mediatek/mtk_ppe.c
+++ b/drivers/net/ethernet/mediatek/mtk_ppe.c
@@ -918,7 +918,7 @@ struct mtk_ppe *mtk_ppe_init(struct mtk_eth *eth, void __iomem *base, int index)
 		mib = dmam_alloc_coherent(ppe->dev, MTK_PPE_ENTRIES * sizeof(*mib),
 					  &ppe->mib_phys, GFP_KERNEL);
 		if (!mib)
-			return NULL;
+			goto err_free_l2_flows;
 
 		ppe->mib_table = mib;
 
@@ -926,7 +926,7 @@ struct mtk_ppe *mtk_ppe_init(struct mtk_eth *eth, void __iomem *base, int index)
 				    GFP_KERNEL);
 
 		if (!acct)
-			return NULL;
+			goto err_free_l2_flows;
 
 		ppe->acct_table = acct;
 	}
-- 
2.51.0

Re: [PATCH net] net: ethernet: mtk_ppe: Fix rhashtable leak in mtk_ppe_init error paths

[Lorenzo Bianconi]

[-- Attachment #1: Type: text/plain, Size: 1641 bytes --]

> In mtk_ppe_init(), when accounting is enabled, the error paths for
> dmam_alloc_coherent(mib) and devm_kzalloc(acct) failures return NULL
> directly, bypassing the err_free_l2_flows label that destroys the
> rhashtable initialized earlier.
> 
> While this leak only occurs during probe (not runtime) and the leaked
> memory is minimal (an empty rhash table), fixing it ensures proper
> error path cleanup consistency.
> 
> Fix by changing the two return NULL statements to goto err_free_l2_flows.
> 
> Fixes: 603ea5e7ffa7 ("net: ethernet: mtk_eth_soc: fix memory leak in error path")
> Signed-off-by: Wayen Yan <win847@gmail.com>

Acked-by: Lorenzo Bianconi <lorenzo@kernel.org>

> ---
>  drivers/net/ethernet/mediatek/mtk_ppe.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/net/ethernet/mediatek/mtk_ppe.c b/drivers/net/ethernet/mediatek/mtk_ppe.c
> index 18279e2a70..8451dc3fd0 100644
> --- a/drivers/net/ethernet/mediatek/mtk_ppe.c
> +++ b/drivers/net/ethernet/mediatek/mtk_ppe.c
> @@ -918,7 +918,7 @@ struct mtk_ppe *mtk_ppe_init(struct mtk_eth *eth, void __iomem *base, int index)
>  		mib = dmam_alloc_coherent(ppe->dev, MTK_PPE_ENTRIES * sizeof(*mib),
>  					  &ppe->mib_phys, GFP_KERNEL);
>  		if (!mib)
> -			return NULL;
> +			goto err_free_l2_flows;
>  
>  		ppe->mib_table = mib;
>  
> @@ -926,7 +926,7 @@ struct mtk_ppe *mtk_ppe_init(struct mtk_eth *eth, void __iomem *base, int index)
>  				    GFP_KERNEL);
>  
>  		if (!acct)
> -			return NULL;
> +			goto err_free_l2_flows;
>  
>  		ppe->acct_table = acct;
>  	}
> -- 
> 2.51.0
> 
> 

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