[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <20200125134521.28ae1fd7@carbon>
Date: Sat, 25 Jan 2020 13:45:21 +0100
From: Jesper Dangaard Brouer <brouer@...hat.com>
To: Lorenzo Bianconi <lorenzo@...nel.org>
Cc: netdev@...r.kernel.org, ilias.apalodimas@...aro.org,
davem@...emloft.net, lorenzo.bianconi@...hat.com, brouer@...hat.com
Subject: Re: [PATCH net 1/2] net: socionext: fix possible user-after-free in
netsec_process_rx
On Sat, 25 Jan 2020 12:48:50 +0100
Lorenzo Bianconi <lorenzo@...nel.org> wrote:
> Fix possible use-after-free in in netsec_process_rx that can occurs if
> the first packet is sent to the normal networking stack and the
> following one is dropped by the bpf program attached to the xdp hook.
> Fix the issue defining the skb pointer in the 'budget' loop
>
> Fixes: ba2b232108d3c ("net: netsec: add XDP support")
> Signed-off-by: Lorenzo Bianconi <lorenzo@...nel.org>
> ---
Acked-by: Jesper Dangaard Brouer <brouer@...hat.com>
> drivers/net/ethernet/socionext/netsec.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/net/ethernet/socionext/netsec.c b/drivers/net/ethernet/socionext/netsec.c
> index 869a498e3b5e..0e12a9856aea 100644
> --- a/drivers/net/ethernet/socionext/netsec.c
> +++ b/drivers/net/ethernet/socionext/netsec.c
> @@ -929,7 +929,6 @@ static int netsec_process_rx(struct netsec_priv *priv, int budget)
> struct netsec_rx_pkt_info rx_info;
> enum dma_data_direction dma_dir;
> struct bpf_prog *xdp_prog;
> - struct sk_buff *skb = NULL;
> u16 xdp_xmit = 0;
> u32 xdp_act = 0;
> int done = 0;
> @@ -943,6 +942,7 @@ static int netsec_process_rx(struct netsec_priv *priv, int budget)
> struct netsec_de *de = dring->vaddr + (DESC_SZ * idx);
> struct netsec_desc *desc = &dring->desc[idx];
> struct page *page = virt_to_page(desc->addr);
> + struct sk_buff *skb = NULL;
> u32 xdp_result = XDP_PASS;
> u16 pkt_len, desc_len;
> dma_addr_t dma_handle;
Yes, this is needed in case an xdp_prog jumps to label 'next:',
skipping the skb = build_skb() assignment.
--
Best regards,
Jesper Dangaard Brouer
MSc.CS, Principal Kernel Engineer at Red Hat
LinkedIn: http://www.linkedin.com/in/brouer
Powered by blists - more mailing lists