IPv6: ADDRCONF(NETDEV_UP): veth0: link is not ready
IPv6: ADDRCONF(NETDEV_CHANGE): veth0: link becomes ready
==================================================================
BUG: KASAN: use-after-free in __lock_acquire+0x3c66/0x5270 kernel/locking/lockdep.c:3092
Read of size 8 at addr ffff8801cafd1a20 by task syz-executor6/11674

CPU: 0 PID: 11674 Comm: syz-executor6 Not tainted 4.4.151-ge917467 #20
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 0000000000000000 0613aeca960dd1b0 ffff8801ca3efa30 ffffffff81e15eed
 ffffea00072bf400 ffff8801cafd1a20 0000000000000000 ffff8801cafd1a20
 0000000000000000 ffff8801ca3efa68 ffffffff8151b390 ffff8801cafd1a20
Call Trace:
 [<ffffffff81e15eed>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81e15eed>] dump_stack+0xc1/0x124 lib/dump_stack.c:51
 [<ffffffff8151b390>] print_address_description+0x6c/0x216 mm/kasan/report.c:252
 [<ffffffff8151b6af>] kasan_report_error mm/kasan/report.c:351 [inline]
 [<ffffffff8151b6af>] kasan_report.cold.7+0x175/0x2f7 mm/kasan/report.c:408
 [<ffffffff814fe644>] __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:429
 [<ffffffff81235d66>] __lock_acquire+0x3c66/0x5270 kernel/locking/lockdep.c:3092
 [<ffffffff81238b4e>] lock_acquire+0x15e/0x450 kernel/locking/lockdep.c:3592
 [<ffffffff838cb3aa>] __raw_spin_lock_bh include/linux/spinlock_api_smp.h:137 [inline]
 [<ffffffff838cb3aa>] _raw_spin_lock_bh+0x3a/0x50 kernel/locking/spinlock.c:175
 [<ffffffff82f2f553>] spin_lock_bh include/linux/spinlock.h:307 [inline]
 [<ffffffff82f2f553>] lock_sock_nested+0x43/0x120 net/core/sock.c:2451
 [<ffffffff835b1070>] lock_sock include/net/sock.h:1493 [inline]
 [<ffffffff835b1070>] pppol2tp_release+0x50/0x310 net/l2tp/l2tp_ppp.c:493
 [<ffffffff82f22d36>] sock_release+0x96/0x1c0 net/socket.c:587
 [<ffffffff82f22e76>] sock_close+0x16/0x20 net/socket.c:1038
 [<ffffffff81528775>] __fput+0x235/0x6f0 fs/file_table.c:208
 [<ffffffff81528cb5>] ____fput+0x15/0x20 fs/file_table.c:244
 [<ffffffff8118ee4f>] 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
 [<ffffffff838cda83>] sysenter_flags_fixed+0xd/0x1a

Allocated by task 11688:
 [<ffffffff81034676>] save_stack_trace+0x26/0x50 arch/x86/kernel/stacktrace.c:63
 [<ffffffff814fd6f3>] save_stack+0x43/0xd0 mm/kasan/kasan.c:512
 [<ffffffff814fd9d7>] set_track mm/kasan/kasan.c:524 [inline]
 [<ffffffff814fd9d7>] kasan_kmalloc+0xc7/0xe0 mm/kasan/kasan.c:616
 [<ffffffff814fa114>] __kmalloc+0x124/0x310 mm/slub.c:3613
 [<ffffffff82f2e414>] kmalloc include/linux/slab.h:481 [inline]
 [<ffffffff82f2e414>] sk_prot_alloc+0x204/0x300 net/core/sock.c:1354
 [<ffffffff82f33dea>] sk_alloc+0x3a/0x3a0 net/core/sock.c:1419
 [<ffffffff835acf93>] pppol2tp_create+0x33/0x1f0 net/l2tp/l2tp_ppp.c:551
 [<ffffffff828f9d96>] pppox_create+0xf6/0x200 drivers/net/ppp/pppox.c:121
 [<ffffffff82f29260>] __sock_create+0x2f0/0x5f0 net/socket.c:1178
 [<ffffffff82f29790>] sock_create net/socket.c:1218 [inline]
 [<ffffffff82f29790>] SYSC_socket net/socket.c:1248 [inline]
 [<ffffffff82f29790>] SyS_socket+0xf0/0x1b0 net/socket.c:1228
 [<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
 [<ffffffff838cda83>] sysenter_flags_fixed+0xd/0x1a

Freed by task 11674:
 [<ffffffff81034676>] save_stack_trace+0x26/0x50 arch/x86/kernel/stacktrace.c:63
 [<ffffffff814fd6f3>] save_stack+0x43/0xd0 mm/kasan/kasan.c:512
 [<ffffffff814fe022>] set_track mm/kasan/kasan.c:524 [inline]
 [<ffffffff814fe022>] kasan_slab_free+0x72/0xc0 mm/kasan/kasan.c:589
 [<ffffffff814fb584>] slab_free_hook mm/slub.c:1383 [inline]
 [<ffffffff814fb584>] slab_free_freelist_hook mm/slub.c:1405 [inline]
 [<ffffffff814fb584>] slab_free mm/slub.c:2859 [inline]
 [<ffffffff814fb584>] kfree+0xf4/0x310 mm/slub.c:3749
 [<ffffffff82f382a7>] sk_prot_free net/core/sock.c:1391 [inline]
 [<ffffffff82f382a7>] sk_destruct+0x407/0x4c0 net/core/sock.c:1472
 [<ffffffff82f383af>] __sk_free+0x4f/0x220 net/core/sock.c:1480
 [<ffffffff82f385b0>] sk_free+0x30/0x40 net/core/sock.c:1491
 [<ffffffff835b054f>] sock_put include/net/sock.h:1639 [inline]
 [<ffffffff835b054f>] pppol2tp_session_sock_put+0x5f/0x70 net/l2tp/l2tp_ppp.c:286
 [<ffffffff835a8dcc>] l2tp_tunnel_closeall+0x23c/0x350 net/l2tp/l2tp_core.c:1277
 [<ffffffff835a995b>] l2tp_udp_encap_destroy+0x8b/0xf0 net/l2tp/l2tp_core.c:1300
 [<ffffffff8349b991>] udpv6_destroy_sock+0xb1/0xd0 net/ipv6/udp.c:1421
 [<ffffffff82f3862d>] sk_common_release+0x6d/0x300 net/core/sock.c:2680
 [<ffffffff8349a645>] udp_lib_close+0x15/0x20 include/net/udp.h:190
 [<ffffffff83301faf>] inet_release+0xff/0x1d0 net/ipv4/af_inet.c:435
 [<ffffffff83424c40>] inet6_release+0x50/0x70 net/ipv6/af_inet6.c:424
 [<ffffffff82f22d36>] sock_release+0x96/0x1c0 net/socket.c:587
 [<ffffffff82f22e76>] sock_close+0x16/0x20 net/socket.c:1038
 [<ffffffff81528775>] __fput+0x235/0x6f0 fs/file_table.c:208
 [<ffffffff81528cb5>] ____fput+0x15/0x20 fs/file_table.c:244
 [<ffffffff8118ee4f>] 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
 [<ffffffff838cda83>] sysenter_flags_fixed+0xd/0x1a

The buggy address belongs to the object at ffff8801cafd1980
 which belongs to the cache kmalloc-2048 of size 2048
The buggy address is located 160 bytes inside of
 2048-byte region [ffff8801cafd1980, ffff8801cafd2180)
The buggy address belongs to the page:
syz-executor2: Corrupted page table at address f77d9be9
PGD 1c9ff8067 PUD ffffffff81490337 BAD
Bad pagetable: 001d [#1] PREEMPT SMP KASAN
Dumping ftrace buffer:
   (ftrace buffer empty)
Modules linked in:
CPU: 1 PID: 3831 Comm: syz-executor2 Not tainted 4.4.151-ge917467 #20
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8801d8da4800 task.stack: ffff8801d9360000
RIP: 0023:[<00000000f77d9be9>]  [<00000000f77d9be9>] 0xf77d9be9
RSP: 002b:000000000845fd7c  EFLAGS: 00010246
RAX: 0000000000000000 RBX: 000000000845fda8 RCX: 00000000f77d9be9
RDX: 0000000000000004 RSI: 0000000000012253 RDI: 0000000000000000
RBP: 0000000000000004 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8801db300000(0063) knlGS:0000000009096900
CS:  0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: ffffc7ff81490dd8 CR3: 00000001d1af8000 CR4: 00000000001606f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400

RIP  [<00000000f77d9be9>] 0xf77d9be9
 RSP <000000000845fd7c>
---[ end trace 25d2bde005389a07 ]---