target/linux/lantiq/patches-5.10/0717-v6.0-net-lantiq_xrx200-confirm-skb-is-allocated-before-us.patch

   1 From c8b043702dc0894c07721c5b019096cebc8c798f Mon Sep 17 00:00:00 2001
   2 From: Aleksander Jan Bajkowski <olek2@wp.pl>
   3 Date: Wed, 24 Aug 2022 23:54:06 +0200
   4 Subject: [PATCH] net: lantiq_xrx200: confirm skb is allocated before using
   5
   6 xrx200_hw_receive() assumes build_skb() always works and goes straight
   7 to skb_reserve(). However, build_skb() can fail under memory pressure.
   8
   9 Add a check in case build_skb() failed to allocate and return NULL.
  10
  11 Fixes: e015593573b3 ("net: lantiq_xrx200: convert to build_skb")
  12 Reported-by: Eric Dumazet <edumazet@google.com>
  13 Signed-off-by: Aleksander Jan Bajkowski <olek2@wp.pl>
  14 Signed-off-by: Jakub Kicinski <kuba@kernel.org>
  15 ---
  16  drivers/net/ethernet/lantiq_xrx200.c | 6 ++++++
  17  1 file changed, 6 insertions(+)
  18
  19 --- a/drivers/net/ethernet/lantiq_xrx200.c
  20 +++ b/drivers/net/ethernet/lantiq_xrx200.c
  21 @@ -239,6 +239,12 @@ static int xrx200_hw_receive(struct xrx2
  22         }
  23
  24         skb = build_skb(buf, priv->rx_skb_size);
  25 +       if (!skb) {
  26 +               skb_free_frag(buf);
  27 +               net_dev->stats.rx_dropped++;
  28 +               return -ENOMEM;
  29 +       }
  30 +
  31         skb_reserve(skb, NET_SKB_PAD);
  32         skb_put(skb, len);
  33