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%3Ba=su...

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