target/linux/generic/pending-5.15/750-skb-Do-mix-page-pool-and-page-referenced-frags-in-GR.patch

   1 From: Alexander Duyck <alexanderduyck@fb.com>
   2 Date: Thu, 26 Jan 2023 11:06:59 -0800
   3 Subject: [PATCH] skb: Do mix page pool and page referenced frags in GRO
   4
   5 GSO should not merge page pool recycled frames with standard reference
   6 counted frames. Traditionally this didn't occur, at least not often.
   7 However as we start looking at adding support for wireless adapters there
   8 becomes the potential to mix the two due to A-MSDU repartitioning frames in
   9 the receive path. There are possibly other places where this may have
  10 occurred however I suspect they must be few and far between as we have not
  11 seen this issue until now.
  12
  13 Fixes: 53e0961da1c7 ("page_pool: add frag page recycling support in page pool")
  14 Reported-by: Felix Fietkau <nbd@nbd.name>
  15 Signed-off-by: Alexander Duyck <alexanderduyck@fb.com>
  16 ---
  17
  18 --- a/net/core/skbuff.c
  19 +++ b/net/core/skbuff.c
  20 @@ -4347,6 +4347,15 @@ int skb_gro_receive(struct sk_buff *p, s
  21         if (unlikely(p->len + len >= 65536 || NAPI_GRO_CB(skb)->flush))
  22                 return -E2BIG;
  23
  24 +       /* Do not splice page pool based packets w/ non-page pool
  25 +        * packets. This can result in reference count issues as page
  26 +        * pool pages will not decrement the reference count and will
  27 +        * instead be immediately returned to the pool or have frag
  28 +        * count decremented.
  29 +        */
  30 +       if (p->pp_recycle != skb->pp_recycle)
  31 +               return -ETOOMANYREFS;
  32 +
  33         lp = NAPI_GRO_CB(p)->last;
  34         pinfo = skb_shinfo(lp);
  35