Thanks for fixing that Eric.
On Tue, Jun 11, 2019 at 7:45 AM Eric Dumazet <eduma...@google.com> wrote:
>
> TCP can send ACK packets on behalf of SYN_RECV sockets.
>
> tcp_v4_send_ack() and tcp_v6_send_response() incorrectly
> dereference sk->sk_mark for non TIME_WAIT sockets.
>
> This field is not defined for SYN_RECV sockets.
>
> Using sk_to_full_sk() should get back to the listener socket.
>
> Note that this also provides a socket pointer to sock_net_uid() calls.
>
> Fixes: 00483690552c ("tcp: Add mark for TIMEWAIT sockets")
> Signed-off-by: Eric Dumazet <eduma...@google.com>
> Cc: Jon Maxwell <jmaxwel...@gmail.com>
> ---
> net/ipv4/tcp_ipv4.c | 6 ++++--
> net/ipv6/tcp_ipv6.c | 1 +
> 2 files changed, 5 insertions(+), 2 deletions(-)
>
> diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
> index
> f059fbd81a84314ae6fef37f600b0cf28bd2ad30..2bb27d5eae78efdff52a741904d7526a234595d8
> 100644
> --- a/net/ipv4/tcp_ipv4.c
> +++ b/net/ipv4/tcp_ipv4.c
> @@ -856,12 +856,14 @@ static void tcp_v4_send_ack(const struct sock *sk,
> if (oif)
> arg.bound_dev_if = oif;
> arg.tos = tos;
> - arg.uid = sock_net_uid(net, sk_fullsock(sk) ? sk : NULL);
> local_bh_disable();
> ctl_sk = this_cpu_read(*net->ipv4.tcp_sk);
> - if (sk)
> + if (sk) {
> + sk = sk_to_full_sk(sk);
> ctl_sk->sk_mark = (sk->sk_state == TCP_TIME_WAIT) ?
> inet_twsk(sk)->tw_mark : sk->sk_mark;
> + }
> + arg.uid = sock_net_uid(net, sk_fullsock(sk) ? sk : NULL);
> ip_send_unicast_reply(ctl_sk,
> skb, &TCP_SKB_CB(skb)->header.h4.opt,
> ip_hdr(skb)->saddr, ip_hdr(skb)->daddr,
> diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
> index
> ad7039137a20f9ad8581d9ca01347c67aa8a8433..ea4dd988bc7f9a90e0d95283e10db5a517a59027
> 100644
> --- a/net/ipv6/tcp_ipv6.c
> +++ b/net/ipv6/tcp_ipv6.c
> @@ -884,6 +884,7 @@ static void tcp_v6_send_response(const struct sock *sk,
> struct sk_buff *skb, u32
> }
>
> if (sk) {
> + sk = sk_to_full_sk(sk);
> if (sk->sk_state == TCP_TIME_WAIT) {
> mark = inet_twsk(sk)->tw_mark;
> /* autoflowlabel relies on buff->hash */
> --
> 2.22.0.rc2.383.gf4fbbf30c2-goog
>
