target/linux/lantiq/patches-5.15/0716-v5.17-net-lantiq_xrx200-fix-use-after-free-bug.patch

   1 From dd830aed23c6e07cd8e2a163742bf3d63c9add08 Mon Sep 17 00:00:00 2001
   2 From: Aleksander Jan Bajkowski <olek2@wp.pl>
   3 Date: Sat, 5 Mar 2022 12:20:39 +0100
   4 Subject: net: lantiq_xrx200: fix use after free bug
   5
   6 The skb->len field is read after the packet is sent to the network
   7 stack. In the meantime, skb can be freed. This patch fixes this bug.
   8
   9 Fixes: c3e6b2c35b34 ("net: lantiq_xrx200: add ingress SG DMA support")
  10 Reported-by: Eric Dumazet <eric.dumazet@gmail.com>
  11 Signed-off-by: Aleksander Jan Bajkowski <olek2@wp.pl>
  12 Acked-by: Hauke Mehrtens <hauke@hauke-m.de>
  13 Signed-off-by: David S. Miller <davem@davemloft.net>
  14 ---
  15  drivers/net/ethernet/lantiq_xrx200.c | 2 +-
  16  1 file changed, 1 insertion(+), 1 deletion(-)
  17
  18 --- a/drivers/net/ethernet/lantiq_xrx200.c
  19 +++ b/drivers/net/ethernet/lantiq_xrx200.c
  20 @@ -260,9 +260,9 @@ static int xrx200_hw_receive(struct xrx2
  21
  22         if (ctl & LTQ_DMA_EOP) {
  23                 ch->skb_head->protocol = eth_type_trans(ch->skb_head, net_dev);
  24 -               netif_receive_skb(ch->skb_head);
  25                 net_dev->stats.rx_packets++;
  26                 net_dev->stats.rx_bytes += ch->skb_head->len;
  27 +               netif_receive_skb(ch->skb_head);
  28                 ch->skb_head = NULL;
  29                 ch->skb_tail = NULL;
  30                 ret = XRX200_DMA_PACKET_COMPLETE;