sock: ignore SCM_RIGHTS and SCM_CREDENTIALS in __sock_cmsg_send
authorSoheil Hassas Yeganeh <soheil@google.com>
Mon, 11 Jul 2016 20:51:26 +0000 (16:51 -0400)
committerDavid S. Miller <davem@davemloft.net>
Mon, 11 Jul 2016 21:32:44 +0000 (14:32 -0700)
commit779f1edec664a7b32b71f7b4702e085a08d60592
treece41ff39e7f4ae46de19e66ed759cd9ae426e595
parent80610229ef7b26615dbb6cb6e873709a60bacc9f
sock: ignore SCM_RIGHTS and SCM_CREDENTIALS in __sock_cmsg_send

Sergei Trofimovich reported that pulse audio sends SCM_CREDENTIALS
as a control message to TCP. Since __sock_cmsg_send does not
support SCM_RIGHTS and SCM_CREDENTIALS, it returns an error and
hence breaks pulse audio over TCP.

SCM_RIGHTS and SCM_CREDENTIALS are sent on the SOL_SOCKET layer
but they semantically belong to SOL_UNIX. Since all
cmsg-processing functions including sock_cmsg_send ignore control
messages of other layers, it is best to ignore SCM_RIGHTS
and SCM_CREDENTIALS for consistency (and also for fixing pulse
audio over TCP).

Fixes: c14ac9451c34 ("sock: enable timestamping using control messages")
Signed-off-by: Soheil Hassas Yeganeh <soheil@google.com>
Reported-by: Sergei Trofimovich <slyfox@gentoo.org>
Tested-by: Sergei Trofimovich <slyfox@gentoo.org>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net/core/sock.c