INIT: Entering runlevel: 2

[info] Using makefile-style concurrent boot in runlevel 2.
[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c.
[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c.
[....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[ ok 8[?25h[?0c.

Debian GNU/Linux 7 syzkaller ttyS0

Warning: Permanently added 'ci-upstream-kasan-gce-8,10.128.0.34' (ECDSA) to the list of known hosts.
net.ipv6.conf.syz0.accept_dad = 0
net.ipv6.conf.syz0.router_solicitations = 0
executing program
syzkaller login: [   51.358472] ==================================================================
[   51.359586] BUG: KASAN: use-after-free in detach_if_pending+0x557/0x610
[   51.360472] Write of size 8 at addr ffff8801d22eb6b8 by task syzkaller708097/2978
[   51.361467] 
[   51.361697] CPU: 0 PID: 2978 Comm: syzkaller708097 Not tainted 4.14.0-rc5+ #134
[   51.362672] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
[   51.363909] Call Trace:
[   51.364266]  dump_stack+0x194/0x257
[   51.364762]  ? arch_local_irq_restore+0x53/0x53
[   51.365385]  ? show_regs_print_info+0x65/0x65
[   51.365986]  ? lock_timer_base+0x1a3/0x2b0
[   51.366555]  ? detach_if_pending+0x557/0x610
[   51.367147]  print_address_description+0x73/0x250
[   51.367791]  ? detach_if_pending+0x557/0x610
[   51.368383]  kasan_report+0x25b/0x340
[   51.368898]  __asan_report_store8_noabort+0x17/0x20
[   51.369564]  detach_if_pending+0x557/0x610
[   51.370134]  ? trace_raw_output_tick_stop+0x130/0x130
[   51.370825]  ? _raw_spin_lock_irqsave+0x9e/0xc0
[   51.371445]  ? lock_timer_base+0x1a3/0x2b0
[   51.372011]  ? lock_timer_base+0x1eb/0x2b0
[   51.372580]  ? __internal_add_timer+0x2d0/0x2d0
[   51.373202]  ? lock_downgrade+0x990/0x990
[   51.373790]  ? trace_hardirqs_on+0xd/0x10
[   51.374353]  try_to_del_timer_sync+0xa2/0x120
[   51.374952]  ? del_timer+0x130/0x130
[   51.375457]  ? del_timer_sync+0xeb/0x240
[   51.376007]  del_timer_sync+0x18a/0x240
[   51.376543]  tun_free_netdev+0x105/0x1b0
[   51.377086]  ? tun_xdp+0x410/0x410
[   51.377560]  ? cpumask_next+0x24/0x30
[   51.378071]  ? netdev_refcnt_read+0xed/0x150
[   51.378981]  ? tun_xdp+0x410/0x410
[   51.382489]  netdev_run_todo+0x870/0xca0
[   51.386517]  ? do_group_exit+0x149/0x400
[   51.390546]  ? mark_held_locks+0xaf/0x100
[   51.394663]  ? register_netdev+0x30/0x30
[   51.398697]  ? find_held_lock+0x35/0x1d0
[   51.402735]  ? lock_downgrade+0x990/0x990
[   51.406946]  ? refcount_sub_and_test+0x115/0x1b0
[   51.411668]  ? refcount_inc+0x50/0x50
[   51.415434]  ? refcount_inc+0x50/0x50
[   51.419207]  ? sk_destruct+0x4c/0x80
[   51.422884]  ? __sk_free+0x5c/0x230
[   51.426478]  ? sk_free+0x2f/0x40
[   51.429809]  ? __tun_detach+0x176/0x1390
[   51.433847]  ? tun_attach+0xfa0/0xfa0
[   51.437621]  ? locks_remove_file+0x3fa/0x5a0
[   51.441997]  ? fcntl_setlk+0x10c0/0x10c0
[   51.446026]  ? __fsnotify_parent+0xb4/0x3a0
[   51.450315]  ? fsnotify+0x1af0/0x1af0
[   51.454086]  ? __tun_detach+0x1390/0x1390
[   51.458202]  rtnl_unlock+0xe/0x10
[   51.461621]  tun_chr_close+0x49/0x60
[   51.465300]  __fput+0x327/0x7e0
[   51.468552]  ? fput+0x140/0x140
[   51.471798]  ? check_same_owner+0x320/0x320
[   51.476092]  ____fput+0x15/0x20
[   51.479340]  task_work_run+0x199/0x270
[   51.483197]  ? task_work_cancel+0x210/0x210
[   51.487484]  ? free_nsproxy+0x185/0x1f0
[   51.491426]  ? switch_task_namespaces+0xa2/0xc0
[   51.496065]  do_exit+0x9b5/0x1ad0
[   51.499484]  ? kvfree+0x3b/0x60
[   51.502731]  ? mm_update_next_owner+0x930/0x930
[   51.507364]  ? rtnl_unlock+0xe/0x10
[   51.510956]  ? __tun_chr_ioctl+0x27a/0x3d20
[   51.515255]  ? tun_chr_read_iter+0x1e0/0x1e0
[   51.519628]  ? find_held_lock+0x35/0x1d0
[   51.523664]  ? __do_page_fault+0x64c/0xd60
[   51.527866]  ? lock_downgrade+0x990/0x990
[   51.531989]  ? handle_mm_fault+0x410/0x8d0
[   51.536205]  ? check_same_owner+0x320/0x320
[   51.540490]  ? up_read+0x1a/0x40
[   51.543820]  ? __do_page_fault+0x3d6/0xd60
[   51.548022]  ? tun_chr_compat_ioctl+0x30/0x30
[   51.552479]  ? tun_chr_ioctl+0x2a/0x40
[   51.556328]  ? tun_chr_ioctl+0x2a/0x40
[   51.560184]  ? do_vfs_ioctl+0x486/0x1520
[   51.564215]  ? ioctl_preallocate+0x2b0/0x2b0
[   51.568598]  ? selinux_capable+0x40/0x40
[   51.572627]  ? putname+0xf3/0x130
[   51.576053]  do_group_exit+0x149/0x400
[   51.579909]  ? SyS_exit+0x30/0x30
[   51.583328]  ? trace_hardirqs_on_caller+0x421/0x5c0
[   51.588312]  ? trace_hardirqs_on_thunk+0x1a/0x1c
[   51.593035]  SyS_exit_group+0x1d/0x20
[   51.596803]  entry_SYSCALL_64_fastpath+0x1f/0xbe
[   51.601521] RIP: 0033:0x4452e9
[   51.604674] RSP: 002b:00007ffc59dde1a8 EFLAGS: 00000202 ORIG_RAX: 00000000000000e7
[   51.612352] RAX: ffffffffffffffda RBX: 00007ffc59dde1e0 RCX: 00000000004452e9
[   51.619585] RDX: 00000000004452e9 RSI: 0000000020927fd8 RDI: 0000000000000001
[   51.626819] RBP: 0000000000000082 R08: 0000000000000000 R09: 00007ffc59dde1e0
[   51.634051] R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000402690
[   51.641287] R13: 0000000000402720 R14: 0000000000000000 R15: 0000000000000000
[   51.648537] 
[   51.650130] Allocated by task 2978:
[   51.653725]  save_stack_trace+0x16/0x20
[   51.657665]  save_stack+0x43/0xd0
[   51.661081]  kasan_kmalloc+0xad/0xe0
[   51.664758]  __kmalloc_node+0x47/0x70
[   51.668522]  kvmalloc_node+0x64/0xd0
[   51.672200]  alloc_netdev_mqs+0x16e/0xed0
[   51.676310]  __tun_chr_ioctl+0x12b2/0x3d20
[   51.680510]  tun_chr_ioctl+0x2a/0x40
[   51.684187]  do_vfs_ioctl+0x1b1/0x1520
[   51.688038]  SyS_ioctl+0x8f/0xc0
[   51.691370]  entry_SYSCALL_64_fastpath+0x1f/0xbe
[   51.696085] 
[   51.697678] Freed by task 2978:
[   51.700930]  save_stack_trace+0x16/0x20
[   51.704867]  save_stack+0x43/0xd0
[   51.708283]  kasan_slab_free+0x71/0xc0
[   51.712473]  kfree+0xca/0x250
[   51.715544]  kvfree+0x36/0x60
[   51.718615]  free_netdev+0x2cf/0x360
[   51.722293]  __tun_chr_ioctl+0x2cea/0x3d20
[   51.726490]  tun_chr_ioctl+0x2a/0x40
[   51.730168]  do_vfs_ioctl+0x1b1/0x1520
[   51.734018]  SyS_ioctl+0x8f/0xc0
[   51.737350]  entry_SYSCALL_64_fastpath+0x1f/0xbe
[   51.742065] 
[   51.743658] The buggy address belongs to the object at ffff8801d22e8380
[   51.743658]  which belongs to the cache kmalloc-16384 of size 16384
[   51.756626] The buggy address is located 13112 bytes inside of
[   51.756626]  16384-byte region [ffff8801d22e8380, ffff8801d22ec380)
[   51.768808] The buggy address belongs to the page:
[   51.773704] page:ffffea000748ba00 count:1 mapcount:0 mapping:ffff8801d22e8380 index:0x0 compound_mapcount: 0
[   51.783637] flags: 0x200000000008100(slab|head)
[   51.788277] raw: 0200000000008100 ffff8801d22e8380 0000000000000000 0000000100000001
[   51.796122] raw: ffffea000744fc20 ffff8801dac01c48 ffff8801dac02200 0000000000000000
[   51.803963] page dumped because: kasan: bad access detected
[   51.809634] 
[   51.811228] Memory state around the buggy address:
[   51.816120]  ffff8801d22eb580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[   51.823445]  ffff8801d22eb600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[   51.830768] >ffff8801d22eb680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[   51.838088]                                         ^
[   51.843240]  ffff8801d22eb700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[   51.850569]  ffff8801d22eb780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[   51.857890] ==================================================================
[   51.865210] Disabling lock debugging due to kernel taint
[   51.870622] Kernel panic - not syncing: panic_on_warn set ...
[   51.870622] 
[   51.877947] CPU: 0 PID: 2978 Comm: syzkaller708097 Tainted: G    B           4.14.0-rc5+ #134
[   51.886570] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
[   51.895908] Call Trace:
[   51.898463]  dump_stack+0x194/0x257
[   51.902056]  ? arch_local_irq_restore+0x53/0x53
[   51.906687]  ? kasan_end_report+0x32/0x50
[   51.910798]  ? lock_downgrade+0x990/0x990
[   51.914910]  ? detach_if_pending+0x510/0x610
[   51.919282]  panic+0x1e4/0x417
[   51.922436]  ? __warn+0x1d9/0x1d9
[   51.925858]  ? detach_if_pending+0x557/0x610
[   51.930228]  kasan_end_report+0x50/0x50
[   51.934168]  kasan_report+0x144/0x340
[   51.937931]  __asan_report_store8_noabort+0x17/0x20
[   51.942910]  detach_if_pending+0x557/0x610
[   51.947109]  ? trace_raw_output_tick_stop+0x130/0x130
[   51.952261]  ? _raw_spin_lock_irqsave+0x9e/0xc0
[   51.956891]  ? lock_timer_base+0x1a3/0x2b0
[   51.961088]  ? lock_timer_base+0x1eb/0x2b0
[   51.965288]  ? __internal_add_timer+0x2d0/0x2d0
[   51.969923]  ? lock_downgrade+0x990/0x990
[   51.974034]  ? trace_hardirqs_on+0xd/0x10
[   51.978149]  try_to_del_timer_sync+0xa2/0x120
[   51.982606]  ? del_timer+0x130/0x130
[   51.986283]  ? del_timer_sync+0xeb/0x240
[   51.990310]  del_timer_sync+0x18a/0x240
[   51.994250]  tun_free_netdev+0x105/0x1b0
[   51.998274]  ? tun_xdp+0x410/0x410
[   52.001778]  ? cpumask_next+0x24/0x30
[   52.005544]  ? netdev_refcnt_read+0xed/0x150
[   52.009917]  ? tun_xdp+0x410/0x410
[   52.013421]  netdev_run_todo+0x870/0xca0
[   52.017447]  ? do_group_exit+0x149/0x400
[   52.021474]  ? mark_held_locks+0xaf/0x100
[   52.025583]  ? register_netdev+0x30/0x30
[   52.029608]  ? find_held_lock+0x35/0x1d0
[   52.033637]  ? lock_downgrade+0x990/0x990
[   52.037751]  ? refcount_sub_and_test+0x115/0x1b0
[   52.042470]  ? refcount_inc+0x50/0x50
[   52.046238]  ? refcount_inc+0x50/0x50
[   52.050005]  ? sk_destruct+0x4c/0x80
[   52.053680]  ? __sk_free+0x5c/0x230
[   52.057270]  ? sk_free+0x2f/0x40
[   52.060600]  ? __tun_detach+0x176/0x1390
[   52.064627]  ? tun_attach+0xfa0/0xfa0
[   52.068395]  ? locks_remove_file+0x3fa/0x5a0
[   52.072767]  ? fcntl_setlk+0x10c0/0x10c0
[   52.076794]  ? __fsnotify_parent+0xb4/0x3a0
[   52.081079]  ? fsnotify+0x1af0/0x1af0
[   52.084847]  ? __tun_detach+0x1390/0x1390
[   52.088961]  rtnl_unlock+0xe/0x10
[   52.092379]  tun_chr_close+0x49/0x60
[   52.096055]  __fput+0x327/0x7e0
[   52.099300]  ? fput+0x140/0x140
[   52.102543]  ? check_same_owner+0x320/0x320
[   52.106829]  ____fput+0x15/0x20
[   52.110071]  task_work_run+0x199/0x270
[   52.113923]  ? task_work_cancel+0x210/0x210
[   52.118209]  ? free_nsproxy+0x185/0x1f0
[   52.122146]  ? switch_task_namespaces+0xa2/0xc0
[   52.126780]  do_exit+0x9b5/0x1ad0
[   52.130199]  ? kvfree+0x3b/0x60
[   52.133442]  ? mm_update_next_owner+0x930/0x930
[   52.138073]  ? rtnl_unlock+0xe/0x10
[   52.141664]  ? __tun_chr_ioctl+0x27a/0x3d20
[   52.145954]  ? tun_chr_read_iter+0x1e0/0x1e0
[   52.150326]  ? find_held_lock+0x35/0x1d0
[   52.154354]  ? __do_page_fault+0x64c/0xd60
[   52.158552]  ? lock_downgrade+0x990/0x990
[   52.162668]  ? handle_mm_fault+0x410/0x8d0
[   52.166872]  ? check_same_owner+0x320/0x320
[   52.171155]  ? up_read+0x1a/0x40
[   52.174483]  ? __do_page_fault+0x3d6/0xd60
[   52.178682]  ? tun_chr_compat_ioctl+0x30/0x30
[   52.183138]  ? tun_chr_ioctl+0x2a/0x40
[   52.186987]  ? tun_chr_ioctl+0x2a/0x40
[   52.190839]  ? do_vfs_ioctl+0x486/0x1520
[   52.194874]  ? ioctl_preallocate+0x2b0/0x2b0
[   52.199247]  ? selinux_capable+0x40/0x40
[   52.203272]  ? putname+0xf3/0x130
[   52.206692]  do_group_exit+0x149/0x400
[   52.210542]  ? SyS_exit+0x30/0x30
[   52.213959]  ? trace_hardirqs_on_caller+0x421/0x5c0
[   52.218940]  ? trace_hardirqs_on_thunk+0x1a/0x1c
[   52.223660]  SyS_exit_group+0x1d/0x20
[   52.227426]  entry_SYSCALL_64_fastpath+0x1f/0xbe
[   52.232145] RIP: 0033:0x4452e9
[   52.235298] RSP: 002b:00007ffc59dde1a8 EFLAGS: 00000202 ORIG_RAX: 00000000000000e7
[   52.242970] RAX: ffffffffffffffda RBX: 00007ffc59dde1e0 RCX: 00000000004452e9
[   52.250214] RDX: 00000000004452e9 RSI: 0000000020927fd8 RDI: 0000000000000001
[   52.257454] RBP: 0000000000000082 R08: 0000000000000000 R09: 00007ffc59dde1e0
[   52.264689] R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000402690
[   52.271923] R13: 0000000000402720 R14: 0000000000000000 R15: 0000000000000000