Subject: RE: [PATCH v2 net] net: ngbe: fix memory leak in ngbe_probe() error path

From: Jiawen Wu <[email-masked]>
Date: Tue, 15 Apr 2025 10:17:04 +0800

On Sat, Apr 12, 2025 11:49 PM, Abdun Nihaal wrote:
> When ngbe_sw_init() is called, memory is allocated for wx->rss_key
> in wx_init_rss_key(). However, in ngbe_probe() function, the subsequent
> error paths after ngbe_sw_init() don't free the rss_key. Fix that by
> freeing it in error path along with wx->mac_table.
> 
> Also change the label to which execution jumps when ngbe_sw_init()
> fails, because otherwise, it could lead to a double free for rss_key,
> when the mac_table allocation fails in wx_sw_init().
> 
> Fixes: 02338c484ab6 ("net: ngbe: Initialize sw info and register netdev")
> Signed-off-by: Abdun Nihaal <[email-masked]>
> ---
> v1 -> v2:
> - Add fixes tag, as suggested by Markus and Jakub.
> - Also set the branch target as net instead of net-next as it is a fix
> 
> v1 link: https://lore.kernel.org/all/[email-masked]
> 
>  drivers/net/ethernet/wangxun/ngbe/ngbe_main.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/net/ethernet/wangxun/ngbe/ngbe_main.c b/drivers/net/ethernet/wangxun/ngbe/ngbe_main.c
> index a6159214ec0a..91b3055a5a9f 100644
> --- a/drivers/net/ethernet/wangxun/ngbe/ngbe_main.c
> +++ b/drivers/net/ethernet/wangxun/ngbe/ngbe_main.c
> @@ -625,7 +625,7 @@ static int ngbe_probe(struct pci_dev *pdev,
>  	/* setup the private structure */
>  	err = ngbe_sw_init(wx);
>  	if (err)
> -		goto err_free_mac_table;
> +		goto err_pci_release_regions;
> 
>  	/* check if flash load is done after hw power up */
>  	err = wx_check_flash_load(wx, NGBE_SPI_ILDR_STATUS_PERST);
> @@ -719,6 +719,7 @@ static int ngbe_probe(struct pci_dev *pdev,
>  err_clear_interrupt_scheme:
>  	wx_clear_interrupt_scheme(wx);
>  err_free_mac_table:
> +	kfree(wx->rss_key);
>  	kfree(wx->mac_table);
>  err_pci_release_regions:
>  	pci_release_selected_regions(pdev,
> --
> 2.47.2
> 

Reviewed-by: Jiawen Wu <[email-masked]>

Thanks Abdun,
I think this release bug is also present in txgbe driver.