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

netlink: reset extack earlier in netlink_rcv_skb

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: netlink-reset-extack-earlier-in-netlink_rcv_skb.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 Jan 28 17:35:08 CET 2018

From: Xin Long lucien.xin@gmail.com Date: Thu, 18 Jan 2018 14:48:03 +0800 Subject: netlink: reset extack earlier in netlink_rcv_skb

From: Xin Long lucien.xin@gmail.com

[ Upstream commit cd443f1e91ca600a092e780e8250cd6a2954b763 ]

Move up the extack reset/initialization in netlink_rcv_skb, so that those 'goto ack' will not skip it. Otherwise, later on netlink_ack may use the uninitialized extack and cause kernel crash.

Fixes: cbbdf8433a5f ("netlink: extack needs to be reset each time through loop") Reported-by: syzbot+03bee3680a37466775e7@syzkaller.appspotmail.com Signed-off-by: Xin Long lucien.xin@gmail.com Acked-by: David Ahern dsahern@gmail.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/netlink/af_netlink.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/net/netlink/af_netlink.c +++ b/net/netlink/af_netlink.c @@ -2400,6 +2400,7 @@ int netlink_rcv_skb(struct sk_buff *skb, while (skb->len >= nlmsg_total_size(0)) { int msglen;

+ memset(&extack, 0, sizeof(extack)); nlh = nlmsg_hdr(skb); err = 0;

@@ -2414,7 +2415,6 @@ int netlink_rcv_skb(struct sk_buff *skb, if (nlh->nlmsg_type < NLMSG_MIN_TYPE) goto ack;

- memset(&extack, 0, sizeof(extack)); err = cb(skb, nlh, &extack); if (err == -EINTR) goto skip;

Patches currently in stable-queue which might be from lucien.xin@gmail.com are

queue-4.14/sctp-do-not-allow-the-v4-socket-to-bind-a-v4mapped-v6-address.patch queue-4.14/sctp-reinit-stream-if-stream-outcnt-has-been-change-by-sinit-in-sendmsg.patch queue-4.14/pppoe-take-needed_headroom-of-lower-device-into-account-on-xmit.patch queue-4.14/sctp-return-error-if-the-asoc-has-been-peeled-off-in-sctp_wait_for_sndbuf.patch queue-4.14/netlink-reset-extack-earlier-in-netlink_rcv_skb.patch