Skip to content
  • Willem de Bruijn's avatar
    ip: Fix SO_MARK in RST, ACK and ICMP packets · 0da7536f
    Willem de Bruijn authored
    When no full socket is available, skbs are sent over a per-netns
    control socket. Its sk_mark is temporarily adjusted to match that
    of the real (request or timewait) socket or to reflect an incoming
    skb, so that the outgoing skb inherits this in __ip_make_skb.
    
    Introduction of the socket cookie mark field broke this. Now the
    skb is set through the cookie and cork:
    
    <caller>		# init sockc.mark from sk_mark or cmsg
    ip_append_data
      ip_setup_cork		# convert sockc.mark to cork mark
    ip_push_pending_frames
      ip_finish_skb
        __ip_make_skb	# set skb->mark to cork mark
    
    But I missed these special control sockets. Update all callers of
    __ip(6)_make_skb that were originally missed.
    
    For IPv6, the same two icmp(v6) paths are affected. The third
    case is not, as commit 92e55f41 ("tcp: don't annotate
    mark on control socket from tcp_v6_send_response()") replaced
    the ctl_sk->sk_mark with passing the mark field directly as a
    function argument. That commit predates the commit that
    introduced the bug.
    
    Fixes: c6af0c22
    
     ("ip: support SO_MARK cmsg")
    Signed-off-by: default avatarWillem de Bruijn <willemb@google.com>
    Reported-by: default avatarMartin KaFai Lau <kafai@fb.com>
    Reviewed-by: default avatarMartin KaFai Lau <kafai@fb.com>
    Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
    0da7536f