SELinux: unrecognized netlink message: protocol=0 nlmsg_type=27 sclass=netlink_route_socket
SELinux: unrecognized netlink message: protocol=0 nlmsg_type=27 sclass=netlink_route_socket
==================================================================
BUG: KASAN: use-after-free in pppol2tp_session_destruct+0xf2/0x110 net/l2tp/l2tp_ppp.c:476
Read of size 4 at addr ffff8800ac262500 by task syz-executor0/10410

CPU: 0 PID: 10410 Comm: syz-executor0 Not tainted 4.4.145-g2241aa9 #14
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 0000000000000000 f1c4f66473278112 ffff8800a2cf7c20 ffffffff81e123cd
 ffffea0002b09880 ffff8800ac262500 0000000000000000 ffff8800ac262500
 ffffffff82f1eea0 ffff8800a2cf7c58 ffffffff81517d66 ffff8800ac262500
Call Trace:
 [<ffffffff81e123cd>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81e123cd>] dump_stack+0xc1/0x124 lib/dump_stack.c:51
 [<ffffffff81517d66>] print_address_description+0x6c/0x216 mm/kasan/report.c:252
 [<ffffffff81518085>] kasan_report_error mm/kasan/report.c:351 [inline]
 [<ffffffff81518085>] kasan_report.cold.7+0x175/0x2f7 mm/kasan/report.c:408
 [<ffffffff814fbb54>] __asan_report_load4_noabort+0x14/0x20 mm/kasan/report.c:428
 [<ffffffff835ac892>] pppol2tp_session_destruct+0xf2/0x110 net/l2tp/l2tp_ppp.c:476
 [<ffffffff82f33f1c>] sk_destruct+0x4c/0x4c0 net/core/sock.c:1447
 [<ffffffff82f343df>] __sk_free+0x4f/0x220 net/core/sock.c:1480
 [<ffffffff82f345e0>] sk_free+0x30/0x40 net/core/sock.c:1491
 [<ffffffff835ad64a>] sock_put include/net/sock.h:1639 [inline]
 [<ffffffff835ad64a>] pppol2tp_release+0x26a/0x310 net/l2tp/l2tp_ppp.c:518
 [<ffffffff82f1ed76>] sock_release+0x96/0x1c0 net/socket.c:586
 [<ffffffff82f1eeb6>] sock_close+0x16/0x20 net/socket.c:1037
 [<ffffffff81525155>] __fput+0x235/0x6f0 fs/file_table.c:208
 [<ffffffff81525695>] ____fput+0x15/0x20 fs/file_table.c:244
 [<ffffffff8118e00f>] task_work_run+0x10f/0x190 kernel/task_work.c:115
 [<ffffffff8100362d>] tracehook_notify_resume include/linux/tracehook.h:191 [inline]
 [<ffffffff8100362d>] exit_to_usermode_loop+0x13d/0x160 arch/x86/entry/common.c:253
 [<ffffffff8100708e>] prepare_exit_to_usermode arch/x86/entry/common.c:284 [inline]
 [<ffffffff8100708e>] syscall_return_slowpath arch/x86/entry/common.c:349 [inline]
 [<ffffffff8100708e>] do_syscall_32_irqs_on arch/x86/entry/common.c:399 [inline]
 [<ffffffff8100708e>] do_fast_syscall_32+0x61e/0x8b0 arch/x86/entry/common.c:460
 [<ffffffff838c9e43>] sysenter_flags_fixed+0xd/0x1a

Allocated by task 10410:
 [<ffffffff81034676>] save_stack_trace+0x26/0x50 arch/x86/kernel/stacktrace.c:63
 [<ffffffff814fac23>] save_stack+0x43/0xd0 mm/kasan/kasan.c:512
 [<ffffffff814faf07>] set_track mm/kasan/kasan.c:524 [inline]
 [<ffffffff814faf07>] kasan_kmalloc+0xc7/0xe0 mm/kasan/kasan.c:616
 [<ffffffff814f7624>] __kmalloc+0x124/0x310 mm/slub.c:3613
 [<ffffffff835a5ee9>] kmalloc include/linux/slab.h:481 [inline]
 [<ffffffff835a5ee9>] kzalloc include/linux/slab.h:620 [inline]
 [<ffffffff835a5ee9>] l2tp_session_create+0x39/0x1030 net/l2tp/l2tp_core.c:1748
 [<ffffffff835aabf0>] pppol2tp_connect+0x10f0/0x1910 net/l2tp/l2tp_ppp.c:725
 [<ffffffff82f23798>] SYSC_connect+0x1b8/0x300 net/socket.c:1557
 [<ffffffff82f260d4>] SyS_connect+0x24/0x30 net/socket.c:1538
 [<ffffffff81006d94>] do_syscall_32_irqs_on arch/x86/entry/common.c:393 [inline]
 [<ffffffff81006d94>] do_fast_syscall_32+0x324/0x8b0 arch/x86/entry/common.c:460
 [<ffffffff838c9e43>] sysenter_flags_fixed+0xd/0x1a

Freed by task 10415:
 [<ffffffff81034676>] save_stack_trace+0x26/0x50 arch/x86/kernel/stacktrace.c:63
 [<ffffffff814fac23>] save_stack+0x43/0xd0 mm/kasan/kasan.c:512
 [<ffffffff814fb552>] set_track mm/kasan/kasan.c:524 [inline]
 [<ffffffff814fb552>] kasan_slab_free+0x72/0xc0 mm/kasan/kasan.c:589
 [<ffffffff814f8a54>] slab_free_hook mm/slub.c:1383 [inline]
 [<ffffffff814f8a54>] slab_free_freelist_hook mm/slub.c:1405 [inline]
 [<ffffffff814f8a54>] slab_free mm/slub.c:2859 [inline]
 [<ffffffff814f8a54>] kfree+0xf4/0x310 mm/slub.c:3749
 [<ffffffff835a2e50>] l2tp_session_free+0x170/0x200 net/l2tp/l2tp_core.c:1676
 [<ffffffff835a5209>] l2tp_session_dec_refcount_1 net/l2tp/l2tp_core.h:293 [inline]
 [<ffffffff835a5209>] l2tp_tunnel_closeall+0x2b9/0x350 net/l2tp/l2tp_core.c:1279
 [<ffffffff835a5d1b>] l2tp_udp_encap_destroy+0x8b/0xf0 net/l2tp/l2tp_core.c:1300
 [<ffffffff83497d21>] udpv6_destroy_sock+0xb1/0xd0 net/ipv6/udp.c:1421
 [<ffffffff82f3465d>] sk_common_release+0x6d/0x300 net/core/sock.c:2680
 [<ffffffff834969d5>] udp_lib_close+0x15/0x20 include/net/udp.h:190
 [<ffffffff832fe2cf>] inet_release+0xff/0x1d0 net/ipv4/af_inet.c:435
 [<ffffffff83420fd0>] inet6_release+0x50/0x70 net/ipv6/af_inet6.c:424
 [<ffffffff82f1ed76>] sock_release+0x96/0x1c0 net/socket.c:586
 [<ffffffff82f1eeb6>] sock_close+0x16/0x20 net/socket.c:1037
 [<ffffffff81525155>] __fput+0x235/0x6f0 fs/file_table.c:208
 [<ffffffff81525695>] ____fput+0x15/0x20 fs/file_table.c:244
 [<ffffffff8118e00f>] task_work_run+0x10f/0x190 kernel/task_work.c:115
 [<ffffffff8100362d>] tracehook_notify_resume include/linux/tracehook.h:191 [inline]
 [<ffffffff8100362d>] exit_to_usermode_loop+0x13d/0x160 arch/x86/entry/common.c:253
 [<ffffffff8100708e>] prepare_exit_to_usermode arch/x86/entry/common.c:284 [inline]
 [<ffffffff8100708e>] syscall_return_slowpath arch/x86/entry/common.c:349 [inline]
 [<ffffffff8100708e>] do_syscall_32_irqs_on arch/x86/entry/common.c:399 [inline]
 [<ffffffff8100708e>] do_fast_syscall_32+0x61e/0x8b0 arch/x86/entry/common.c:460
 [<ffffffff838c9e43>] sysenter_flags_fixed+0xd/0x1a

The buggy address belongs to the object at ffff8800ac262500
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 0 bytes inside of
 512-byte region [ffff8800ac262500, ffff8800ac262700)
The buggy address belongs to the page:
kasan: CONFIG_KASAN_INLINE enabled
kasan: GPF could be caused by NULL-ptr deref or user memory accessgeneral protection fault: 0000 [#1] PREEMPT SMP KASAN
Dumping ftrace buffer:
   (ftrace buffer empty)
Modules linked in:
CPU: 1 PID: 2025 Comm: udevd Not tainted 4.4.145-g2241aa9 #14
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8801d2eec800 task.stack: ffff8801d2f88000
RIP: 0010:[<ffffffff812318b4>]  [<ffffffff812318b4>] __lock_acquire+0x5f4/0x5270 kernel/locking/lockdep.c:3100
RSP: 0000:ffff8801d2f8f520  EFLAGS: 00010086
RAX: 0000000000000000 RBX: c148da8948dffffc RCX: 1ffffffff0291f61
RDX: dffffc0000000000 RSI: 0000000000000000 RDI: ffffffff8148fb0f
RBP: ffff8801d2f8f6c0 R08: 0000000000000001 R09: 0000000000000001
R10: ffffffff83a456e0 R11: ffff8801d2eec800 R12: 0000000000000000
R13: ffffffff8148fb07 R14: 0000000000000000 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffff8800ac262700 CR3: 000000000440c000 CR4: 00000000001606f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:
 ffffffff812eb53a 00007ffd7974b540 ffff8801d2f8f548 ffffffff8118e1db
 0000000000000000 ffff8801d2f8f5a0 ffffffff8101678b 0000000000000000
 ffff8801d2f8f648 ffffffff83a10aa0 ffff8801d2f88000 ffff8801d2eec800
Call Trace:
 [<ffffffff81237d0e>] lock_acquire+0x15e/0x450 kernel/locking/lockdep.c:3592
 [<ffffffff838c811e>] __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:112 [inline]
 [<ffffffff838c811e>] _raw_spin_lock_irqsave+0x4e/0x70 kernel/locking/spinlock.c:159
 [<ffffffff811c17bc>] try_to_wake_up+0x2c/0xf00 kernel/sched/core.c:1974
 [<ffffffff811c2815>] default_wake_function+0x35/0x50 kernel/sched/core.c:3494
 [<ffffffff8121c166>] __wake_up_common+0xb6/0x150 kernel/sched/wait.c:73
 [<ffffffff8121c25e>] __wake_up_locked+0xe/0x10 kernel/sched/wait.c:105
 [<ffffffff815faff3>] ep_poll_callback+0x173/0x5b0 fs/eventpoll.c:1065
 [<ffffffff8121c166>] __wake_up_common+0xb6/0x150 kernel/sched/wait.c:73
 [<ffffffff8121c234>] __wake_up+0x34/0x50 kernel/sched/wait.c:95
 [<ffffffff8115a310>] signalfd_notify include/linux/signalfd.h:21 [inline]
 [<ffffffff8115a310>] __send_signal+0xf40/0x11b0 kernel/signal.c:1078
 [<ffffffff8115a5ca>] send_signal+0x4a/0xc0 kernel/signal.c:1096
 [<ffffffff8115ccb4>] do_send_sig_info+0xa4/0x130 kernel/signal.c:1151
 [<ffffffff8115db66>] group_send_sig_info+0xf6/0x170 kernel/signal.c:1273
 [<ffffffff81137b95>] forget_original_parent kernel/exit.c:575 [inline]
 [<ffffffff81137b95>] exit_notify kernel/exit.c:599 [inline]
 [<ffffffff81137b95>] do_exit+0x1105/0x26b0 kernel/exit.c:776
 [<ffffffff8113d3b1>] do_group_exit+0x111/0x330 kernel/exit.c:885
 [<ffffffff811607ac>] get_signal+0x4ec/0x14b0 kernel/signal.c:2321
 [<ffffffff8100df4b>] do_signal+0x8b/0x1d30 arch/x86/kernel/signal.c:712
 [<ffffffff8100360a>] exit_to_usermode_loop+0x11a/0x160 arch/x86/entry/common.c:249
 [<ffffffff81006363>] prepare_exit_to_usermode+0xe3/0x100 arch/x86/entry/common.c:284
 [<ffffffff838c9088>] retint_user+0x8/0x3c
Code: 00 fc ff df 44 89 e0 49 8d 7c c5 08 48 89 f9 48 c1 e9 03 80 3c 11 00 0f 85 94 36 00 00 49 8b 5c c5 08 48 85 db 0f 84 21 22 00 00 <f0> ff 83 98 01 00 00 49 8d 83 d8 08 00 00 48 89 c2 48 89 44 24 
RIP  [<ffffffff812318b4>] __lock_acquire+0x5f4/0x5270 kernel/locking/lockdep.c:3100
 RSP <ffff8801d2f8f520>
---[ end trace 005afc22c5241ced ]---