Cong Wang wrote:
> From: Cong Wang <cong.wang@xxxxxxxxxxxxx>
>
> It turns out the skb's in sock receive queue could have
> bad checksums, as both ->poll() and ->recvmsg() validate
> checksums. We have to do the same for ->read_sock() path
> too before they are redirected in sockmap.
>
> Fixes: d7f571188ecf ("udp: Implement ->read_sock() for sockmap")
> Reported-by: Daniel Borkmann <daniel@xxxxxxxxxxxxx>
> Reported-by: John Fastabend <john.fastabend@xxxxxxxxx>
> Cc: Lorenz Bauer <lmb@xxxxxxxxxxxxxx>
> Cc: Jakub Sitnicki <jakub@xxxxxxxxxxxxxx>
> Signed-off-by: Cong Wang <cong.wang@xxxxxxxxxxxxx>
> ---
> net/ipv4/udp.c | 11 +++++++++++
> 1 file changed, 11 insertions(+)
>
> diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
> index 8536b2a7210b..0ae8ab5e05b4 100644
> --- a/net/ipv4/udp.c
> +++ b/net/ipv4/udp.c
> @@ -1808,6 +1808,17 @@ int udp_read_sock(struct sock *sk, read_descriptor_t *desc,
> skb = skb_recv_udp(sk, 0, 1, &err);
> if (!skb)
> return err;
> +
> + if (udp_lib_checksum_complete(skb)) {
> + __UDP_INC_STATS(sock_net(sk), UDP_MIB_CSUMERRORS,
> + IS_UDPLITE(sk));
> + __UDP_INC_STATS(sock_net(sk), UDP_MIB_INERRORS,
> + IS_UDPLITE(sk));
> + atomic_inc(&sk->sk_drops);
> + kfree_skb(skb);
We could use sock_drop() here? Otherwise looks good thanks.
> + continue;
> + }
> +
> used = recv_actor(desc, skb, 0, skb->len);
> if (used <= 0) {
> if (!copied)
> --
> 2.30.2
>
