random: sshd: uninitialized urandom read (32 bytes read)
random: sshd: uninitialized urandom read (32 bytes read)
urandom_read: 1 callbacks suppressed
random: sshd: uninitialized urandom read (32 bytes read)
BUG: unable to handle kernel NULL pointer dereference at 0000000000000080
IP: [<ffffffff836bf9cc>] l2tp_session_free+0x11c/0x200 net/l2tp/l2tp_core.c:1765
PGD 1c24f1067 [   23.608545] PUD 1c24f0067 
Oops: 0002 [#1] PREEMPT SMP KASAN
Dumping ftrace buffer:
   (ftrace buffer empty)
Modules linked in:
CPU: 0 PID: 3735 Comm: syz-executor220 Not tainted 4.9.119-g92e8704 #74
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8801bf569800 task.stack: ffff8801bdae8000
RIP: 0010:[<ffffffff836bf9cc>]  [<ffffffff836bf9cc>] l2tp_session_free+0x11c/0x200 net/l2tp/l2tp_core.c:1765
RSP: 0018:ffff8801bdaefca0  EFLAGS: 00010246
RAX: dffffc0000000000 RBX: ffff8801bd807680 RCX: 0000000000000000
RDX: 1ffff100395d4c30 RSI: ffffffff836bf9a1 RDI: ffff8801caea6180
RBP: ffff8801bdaefcc0 R08: ffff8801bf56a0e8 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffff8801caea6000
R13: ffff8801bd807688 R14: 0000000000000000 R15: ffffffff83015be0
FS:  0000000001d84880(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000080 CR3: 00000001c5333000 CR4: 00000000001606f0
Stack:
 ffff8801bda40880 ffff8801bd807680 ffff8801bda40c50 ffff8801bda40b58
 ffff8801bdaefce8 ffffffff836c72b2 ffff8801bda40cc0 ffff8801bda40880
 ffffffff836c71e0 ffff8801bdaefd20 ffffffff830230f5 ffff8801bda40cc0
Call Trace:
 [<ffffffff836c72b2>] l2tp_session_dec_refcount_1 net/l2tp/l2tp_core.h:297 [inline]
 [<ffffffff836c72b2>] pppol2tp_session_destruct+0xd2/0x110 net/l2tp/l2tp_ppp.c:460
 [<ffffffff830230f5>] __sk_destruct+0x55/0x590 net/core/sock.c:1428
 [<ffffffff8302ab83>] sk_destruct+0x63/0x80 net/core/sock.c:1463
 [<ffffffff8302abef>] __sk_free+0x4f/0x220 net/core/sock.c:1471
 [<ffffffff8302adeb>] sk_free+0x2b/0x40 net/core/sock.c:1482
 [<ffffffff836ca5b9>] sock_put include/net/sock.h:1588 [inline]
 [<ffffffff836ca5b9>] pppol2tp_release+0x239/0x2e0 net/l2tp/l2tp_ppp.c:501
 [<ffffffff83015ab6>] sock_release+0x96/0x1c0 net/socket.c:600
 [<ffffffff83015bf6>] sock_close+0x16/0x20 net/socket.c:1047
 [<ffffffff81578693>] __fput+0x263/0x700 fs/file_table.c:208
 [<ffffffff81578bb5>] ____fput+0x15/0x20 fs/file_table.c:244
 [<ffffffff8119838c>] task_work_run+0x10c/0x180 kernel/task_work.c:116
 [<ffffffff8100559c>] tracehook_notify_resume include/linux/tracehook.h:191 [inline]
 [<ffffffff8100559c>] exit_to_usermode_loop+0xfc/0x120 arch/x86/entry/common.c:161
 [<ffffffff810064d4>] prepare_exit_to_usermode arch/x86/entry/common.c:191 [inline]
 [<ffffffff810064d4>] syscall_return_slowpath arch/x86/entry/common.c:260 [inline]
 [<ffffffff810064d4>] do_syscall_64+0x364/0x490 arch/x86/entry/common.c:287
 [<ffffffff839fccd3>] entry_SYSCALL_64_after_swapgs+0x5d/0xdb
Code: 49 8d bc 24 80 01 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 c6 00 00 00 4d 8b b4 24 80 01 00 00 <f0> 41 ff 8e 80 00 00 00 74 69 e8 f5 f0 c9 fd 4c 89 ea 48 b8 00 
RIP  [<ffffffff836bf9cc>] l2tp_session_free+0x11c/0x200 net/l2tp/l2tp_core.c:1765
 RSP <ffff8801bdaefca0>
CR2: 0000000000000080
---[ end trace 497a4d02c1f69403 ]---