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Date:   Mon, 30 May 2022 12:37:34 +0200
From:   Steffen Klassert <steffen.klassert@secunet.com>
To:     Hangyu Hua <hbh25y@gmail.com>
CC:     <herbert@gondor.apana.org.au>, <davem@davemloft.net>,
        <edumazet@google.com>, <kuba@kernel.org>, <pabeni@redhat.com>,
        <netdev@vger.kernel.org>, <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] xfrm: xfrm_input: fix a possible memory leak in
 xfrm_input()
Message-ID: <20220530103734.GD2517843@gauss3.secunet.de>
References: <20220530102046.41249-1-hbh25y@gmail.com>
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In-Reply-To: <20220530102046.41249-1-hbh25y@gmail.com>
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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@gmail.com>
> ---
>  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.