Re: [PATCH] xfrm: xfrm_input: fix a possible memory leak in xfrm_input()

[Steffen Klassert]

On Mon, May 30, 2022 at 06:20:46PM +0800, Hangyu Hua wrote:
> xfrm_input needs to handle skb internally. But skb is not freed When
> xo->flags & XFRM_GRO == 0 and decaps == 0.
> 
> Fixes: 7785bba299a8 ("esp: Add a software GRO codepath")
> Signed-off-by: Hangyu Hua <hbh25y@xxxxxxxxx>
> ---
>  net/xfrm/xfrm_input.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/net/xfrm/xfrm_input.c b/net/xfrm/xfrm_input.c
> index 144238a50f3d..6f9576352f30 100644
> --- a/net/xfrm/xfrm_input.c
> +++ b/net/xfrm/xfrm_input.c
> @@ -742,7 +742,7 @@ int xfrm_input(struct sk_buff *skb, int nexthdr, __be32 spi, int encap_type)
>  			gro_cells_receive(&gro_cells, skb);
>  			return err;
>  		}
> -
> +		kfree_skb(skb);
>  		return err;
>  	}

Did you test this? The function behind the 'afinfo->the transport_finish()'
pointer handles this skb and frees it in that case.