On 11/07/2018 08:55 PM, David Barmann wrote:
> When setting the SO_MARK socket option, the dst needs to be reset so
> that a new route lookup is performed.
>
> This fixes the case where an application wants to change routing by
> setting a new sk_mark. If this is done after some packets have already
> been sent, the dst is cached and has no effect.
>
> Signed-off-by: David Barmann <david.barm...@stackpath.com>
> ---
> net/core/sock.c | 6 ++++--
> 1 file changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/net/core/sock.c b/net/core/sock.c
> index 7b304e454a38..c74b10be86cb 100644
> --- a/net/core/sock.c
> +++ b/net/core/sock.c
> @@ -952,10 +952,12 @@ int sock_setsockopt(struct socket *sock, int level, int
> optname,
> clear_bit(SOCK_PASSSEC, &sock->flags);
> break;
> case SO_MARK:
> - if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
> + if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)) {
> ret = -EPERM;
> - else
> + } else {
> sk->sk_mark = val;
> + sk_dst_reset(sk);
There is no need to force a sk_dst_reset(sk) if sk_mark was not changed.
I already gave you this feedback, please do not ignore it.
Thanks.
