gve: fix frag_list chaining

gve_rx_append_frags() is able to build skbs chained with frag_list,
like GRO engine.

Problem is that shinfo->frag_list should only be used
for the head of the chain.

All other links should use skb->next pointer.

Otherwise, built skbs are not valid and can cause crashes.

Equivalent code in GRO (skb_gro_receive()) is:

    if (NAPI_GRO_CB(p)->last == p)
        skb_shinfo(p)->frag_list = skb;
    else
        NAPI_GRO_CB(p)->last->next = skb;
    NAPI_GRO_CB(p)->last = skb;

Fixes: 9b8dd5e5ea ("gve: DQO: Add RX path")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Bailey Forrest <bcf@google.com>
Cc: Willem de Bruijn <willemb@google.com>
Cc: Catherine Sullivan <csully@google.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Eric Dumazet 2023-08-31 21:38:12 +00:00 committed by David S. Miller
parent 915d975b2f
commit 817c7cd204

View file

@ -570,7 +570,10 @@ static int gve_rx_append_frags(struct napi_struct *napi,
if (!skb)
return -1;
skb_shinfo(rx->ctx.skb_tail)->frag_list = skb;
if (rx->ctx.skb_tail == rx->ctx.skb_head)
skb_shinfo(rx->ctx.skb_head)->frag_list = skb;
else
rx->ctx.skb_tail->next = skb;
rx->ctx.skb_tail = skb;
num_frags = 0;
}