Patch "ipv6: set all.accept_dad to 0 by default" has been added to the 4.14-stable tree

Patch "ipv6: set all.accept_dad to 0 by default" has been added to the 4.14-stable tree

[gregkh]

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

    ipv6: set all.accept_dad to 0 by default

to the 4.14-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:
     ipv6-set-all.accept_dad-to-0-by-default.patch
and it can be found in the queue-4.14 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From foo@baz Sun Dec 31 11:12:48 CET 2017
From: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Date: Tue, 14 Nov 2017 14:21:32 +0100
Subject: ipv6: set all.accept_dad to 0 by default

From: Nicolas Dichtel <nicolas.dichtel@6wind.com>


[ Upstream commit 094009531612246d9e13f9e0c3ae2205d7f63a0a ]

With commits 35e015e1f577 and a2d3f3e33853, the global 'accept_dad' flag
is also taken into account (default value is 1). If either global or
per-interface flag is non-zero, DAD will be enabled on a given interface.

This is not backward compatible: before those patches, the user could
disable DAD just by setting the per-interface flag to 0. Now, the
user instead needs to set both flags to 0 to actually disable DAD.

Restore the previous behaviour by setting the default for the global
'accept_dad' flag to 0. This way, DAD is still enabled by default,
as per-interface flags are set to 1 on device creation, but setting
them to 0 is enough to disable DAD on a given interface.

- Before 35e015e1f57a7 and a2d3f3e33853:
          global    per-interface    DAD enabled
[default]   1             1              yes
            X             0              no
            X             1              yes

- After 35e015e1f577 and a2d3f3e33853:
          global    per-interface    DAD enabled
[default]   1             1              yes
            0             0              no
            0             1              yes
            1             0              yes

- After this fix:
          global    per-interface    DAD enabled
            1             1              yes
            0             0              no
[default]   0             1              yes
            1             0              yes

Fixes: 35e015e1f577 ("ipv6: fix net.ipv6.conf.all interface DAD handlers")
Fixes: a2d3f3e33853 ("ipv6: fix net.ipv6.conf.all.accept_dad behaviour for real")
CC: Stefano Brivio <sbrivio@redhat.com>
CC: Matteo Croce <mcroce@redhat.com>
CC: Erik Kline <ek@google.com>
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Acked-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 net/ipv6/addrconf.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -231,7 +231,7 @@ static struct ipv6_devconf ipv6_devconf
 	.proxy_ndp		= 0,
 	.accept_source_route	= 0,	/* we do not accept RH0 by default. */
 	.disable_ipv6		= 0,
-	.accept_dad		= 1,
+	.accept_dad		= 0,
 	.suppress_frag_ndisc	= 1,
 	.accept_ra_mtu		= 1,
 	.stable_secret		= {


Patches currently in stable-queue which might be from nicolas.dichtel@6wind.com are

queue-4.14/net-fix-double-free-and-memory-corruption-in-get_net_ns_by_id.patch
queue-4.14/ipv6-set-all.accept_dad-to-0-by-default.patch