From: Daniel Wagner <redacted>

Commit 6a328d8c6f03501657ad580f6f98bf9a42583ff7 changed the update
logic for the socket but it does not update the SCM_RIGHTS update
as well. This patch is based on the net_prio fix commit

48a87cc26c13b68f6cce4e9d769fcb17a6b3e4b8

    net: netprio: fd passed in SCM_RIGHTS datagram not set correctly

    A socket fd passed in a SCM_RIGHTS datagram was not getting
    updated with the new tasks cgrp prioidx. This leaves IO on
    the socket tagged with the old tasks priority.

    To fix this add a check in the scm recvmsg path to update the
    sock cgrp prioidx with the new tasks value.

Let's apply the same fix for net_cls.

Reported-by: Li Zefan <redacted>
Cc: "David S. Miller" <davem-fT/PcQaiUtIeIZ0/mPfg9Q@public.gmane.org>
Cc: "Eric W. Biederman" <ebiederm-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org>
Cc: Al Viro <viro-RmSDqhL/yNMiFSDQTTA3OLVCufUGDwFn@public.gmane.org>
Cc: John Fastabend <redacted>
Cc: Neil Horman <redacted>
Cc: netdev-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
Cc: cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
---
 net/core/scm.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/net/core/scm.c b/net/core/scm.c
index 57fb1ee..905dcc6 100644
--- a/net/core/scm.c
+++ b/net/core/scm.c

@@ -35,6 +35,7 @@
 #include <net/sock.h>
 #include <net/compat.h>
 #include <net/scm.h>
+#include <net/cls_cgroup.h>
 
 
 /*

@@ -302,8 +303,10 @@ void scm_detach_fds(struct msghdr *msg, struct scm_cookie *scm)
 		}
 		/* Bump the usage count and install the file. */
 		sock = sock_from_file(fp[i], &err);
-		if (sock)
+		if (sock) {
 			sock_update_netprioidx(sock->sk, current);
+			sock_update_classid(sock->sk, current);
+		}
 		fd_install(new_fd, get_file(fp[i]));
 	}
 

-- 
1.8.0.rc0