Patch "lwtunnel: valid encap attr check should return 0 when lwtunnel is disabled" has been added to the 4.9-stable tree

This is a note to let you know that I've just added the patch titled

lwtunnel: valid encap attr check should return 0 when lwtunnel is disabled

to the 4.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
lwtunnel-valid-encap-attr-check-should-return-0-when-lwtunnel-is-disabled.patch
and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: David Ahern <[email protected]>
Date: Wed, 8 Feb 2017 09:29:00 -0800
Subject: lwtunnel: valid encap attr check should return 0 when lwtunnel is disabled

From: David Ahern <[email protected]>

[ Upstream commit 2bd137de531367fb573d90150d1872cb2a2095f7 ]

An error was reported upgrading to 4.9.8:

    root@Typhoon:~# ip route add default table 210 nexthop dev eth0 via 10.68.64.1
    weight 1 nexthop dev eth0 via 10.68.64.2 weight 1
    RTNETLINK answers: Operation not supported

The problem occurs when CONFIG_LWTUNNEL is not enabled and a multipath route is submitted.

The point of lwtunnel_valid_encap_type_attr is catch modules that need to be loaded before any references are taken with rntl held. With CONFIG_LWTUNNEL disabled, there will be no modules to load so the lwtunnel_valid_encap_type_attr stub should just return 0.

---
 include/net/lwtunnel.h |    5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

@@ -176,7 +176,10 @@ static inline int lwtunnel_valid_encap_t
 }
 static inline int lwtunnel_valid_encap_type_attr(struct nlattr *attr, int len)
 {
-	return -EOPNOTSUPP;
+	/* return 0 since we are not walking attr looking for
+	 * RTA_ENCAP_TYPE attribute on nexthops.
+	 */
+	return 0;
 }
 
 static inline int lwtunnel_build_state(struct net_device *dev, u16 encap_type,

Patches currently in stable-queue which might be from [email protected] are

queue-4.9/lwtunnel-valid-encap-attr-check-should-return-0-when-lwtunnel-is-disabled.patch