syzbot

random: sshd: uninitialized urandom read (32 bytes read, 38 bits of entropy available)
random: sshd: uninitialized urandom read (32 bytes read, 114 bits of entropy available)
random: sshd: uninitialized urandom read (32 bytes read, 124 bits of entropy available)
random: nonblocking pool is initialized
Kernel panic - not syncing: stack-protector: Kernel stack is corrupted in: ffffffff8330612a

CPU: 1 PID: 3746 Comm: syzkaller074220 Not tainted 4.4.120-gd63fdf6 #28
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 0000000000000000 a7fdacd8bb5dd201 ffff8801c84d7658 ffffffff81d0408d
 ffffffff83843960 ffff8801c84d7730 00000000000005b4 ffff8801cd14a464
 0000000000000040 ffff8801c84d7720 ffffffff8141ab2a 0000000041b58ab3
Call Trace:
 [<ffffffff81d0408d>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81d0408d>] dump_stack+0xc1/0x124 lib/dump_stack.c:51
 [<ffffffff8141ab2a>] panic+0x1aa/0x388 kernel/panic.c:112
 [<ffffffff8112d4a2>] __stack_chk_fail+0x22/0x30 kernel/panic.c:506
 [<ffffffff8330612a>] ip6_xmit+0x16ba/0x1a70 net/ipv6/ip6_output.c:256
 [<ffffffff833c70f6>] inet6_csk_xmit+0x246/0x480 net/ipv6/inet6_connection_sock.c:176
 [<ffffffff83459bef>] l2tp_xmit_core net/l2tp/l2tp_core.c:1084 [inline]
 [<ffffffff83459bef>] l2tp_xmit_skb+0xc2f/0xea0 net/l2tp/l2tp_core.c:1179
 [<ffffffff834666d4>] pppol2tp_sendmsg+0x584/0x7f0 net/l2tp/l2tp_ppp.c:355
 [<ffffffff82deba6a>] sock_sendmsg_nosec net/socket.c:625 [inline]
 [<ffffffff82deba6a>] sock_sendmsg+0xca/0x110 net/socket.c:635
 [<ffffffff82ded641>] ___sys_sendmsg+0x6c1/0x7c0 net/socket.c:1962
 [<ffffffff82def693>] __sys_sendmsg+0xd3/0x190 net/socket.c:1996
 [<ffffffff82def77d>] SYSC_sendmsg net/socket.c:2007 [inline]
 [<ffffffff82def77d>] SyS_sendmsg+0x2d/0x50 net/socket.c:2003
 [<ffffffff8377395f>] entry_SYSCALL_64_fastpath+0x1c/0x98
Dumping ftrace buffer:
   (ftrace buffer empty)
Kernel Offset: disabled
Rebooting in 86400 seconds..