This is a note to let you know that I've just added the patch titled l2tp: avoid use-after-free caused by l2tp_ip_backlog_recv to the 4.10-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: l2tp-avoid-use-after-free-caused-by-l2tp_ip_backlog_recv.patch and it can be found in the queue-4.10 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From foo@baz Sat Mar 18 22:03:53 CST 2017 From: Paul Hüber <phueber@xxxxxxxxx> Date: Sun, 26 Feb 2017 17:58:19 +0100 Subject: l2tp: avoid use-after-free caused by l2tp_ip_backlog_recv From: Paul Hüber <phueber@xxxxxxxxx> [ Upstream commit 51fb60eb162ab84c5edf2ae9c63cf0b878e5547e ] l2tp_ip_backlog_recv may not return -1 if the packet gets dropped. The return value is passed up to ip_local_deliver_finish, which treats negative values as an IP protocol number for resubmission. Signed-off-by: Paul Hüber <phueber@xxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- net/l2tp/l2tp_ip.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/net/l2tp/l2tp_ip.c +++ b/net/l2tp/l2tp_ip.c @@ -381,7 +381,7 @@ static int l2tp_ip_backlog_recv(struct s drop: IP_INC_STATS(sock_net(sk), IPSTATS_MIB_INDISCARDS); kfree_skb(skb); - return -1; + return 0; } /* Userspace will call sendmsg() on the tunnel socket to send L2TP Patches currently in stable-queue which might be from phueber@xxxxxxxxx are queue-4.10/l2tp-avoid-use-after-free-caused-by-l2tp_ip_backlog_recv.patch