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-386-0,10.128.0.6' (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: [   34.444304] ==================================================================
[   34.451728] BUG: KASAN: use-after-free in detach_if_pending+0x557/0x610
[   34.458455] Write of size 8 at addr ffff8801cff13780 by task syzkaller995923/2986
[   34.466045] 
[   34.467647] CPU: 0 PID: 2986 Comm: syzkaller995923 Not tainted 4.14.0-rc3+ #23
[   34.474976] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
[   34.484301] Call Trace:
[   34.486863]  dump_stack+0x194/0x257
[   34.490464]  ? arch_local_irq_restore+0x53/0x53
[   34.495103]  ? show_regs_print_info+0x65/0x65
[   34.499571]  ? lock_timer_base+0x1a3/0x2b0
[   34.503777]  ? detach_if_pending+0x557/0x610
[   34.508157]  print_address_description+0x73/0x250
[   34.512970]  ? detach_if_pending+0x557/0x610
[   34.517349]  kasan_report+0x25b/0x340
[   34.521122]  __asan_report_store8_noabort+0x17/0x20
[   34.526107]  detach_if_pending+0x557/0x610
[   34.530317]  ? trace_raw_output_tick_stop+0x130/0x130
[   34.535480]  ? _raw_spin_lock_irqsave+0x9e/0xc0
[   34.540115]  ? lock_timer_base+0x1a3/0x2b0
[   34.544321]  ? lock_timer_base+0x1eb/0x2b0
[   34.548529]  ? __internal_add_timer+0x2d0/0x2d0
[   34.553170]  ? trace_hardirqs_on+0xd/0x10
[   34.557297]  try_to_del_timer_sync+0xa2/0x120
[   34.561762]  ? del_timer+0x130/0x130
[   34.565448]  ? del_timer_sync+0xeb/0x240
[   34.569487]  del_timer_sync+0x18a/0x240
[   34.573437]  tun_free_netdev+0x105/0x1b0
[   34.577468]  ? tun_xdp+0x410/0x410
[   34.580975]  ? cpumask_next+0x24/0x30
[   34.584747]  ? netdev_refcnt_read+0xed/0x150
[   34.589129]  ? tun_xdp+0x410/0x410
[   34.592649]  netdev_run_todo+0x870/0xca0
[   34.596682]  ? do_group_exit+0x149/0x400
[   34.600717]  ? register_netdev+0x30/0x30
[   34.604752]  ? lock_downgrade+0x990/0x990
[   34.608870]  ? trace_hardirqs_on+0xd/0x10
[   34.613005]  ? refcount_sub_and_test+0x115/0x1b0
[   34.617730]  ? refcount_inc+0x50/0x50
[   34.621500]  ? refcount_inc+0x50/0x50
[   34.625278]  ? sk_destruct+0x4c/0x80
[   34.628961]  ? __sk_free+0x5c/0x230
[   34.632559]  ? sk_free+0x2f/0x40
[   34.635895]  ? __tun_detach+0x176/0x1390
[   34.639936]  ? tun_attach+0xf90/0xf90
[   34.643717]  ? locks_remove_file+0x3fa/0x5a0
[   34.648099]  ? fcntl_setlk+0x10d0/0x10d0
[   34.652137]  ? __fsnotify_parent+0xb4/0x3a0
[   34.656432]  ? fsnotify+0x1af0/0x1af0
[   34.660206]  ? __tun_detach+0x1390/0x1390
[   34.664328]  ? __tun_detach+0x1390/0x1390
[   34.668451]  rtnl_unlock+0xe/0x10
[   34.671873]  tun_chr_close+0x49/0x60
[   34.675556]  __fput+0x333/0x7f0
[   34.678811]  ? fput+0x140/0x140
[   34.682064]  ? check_same_owner+0x320/0x320
[   34.686362]  ____fput+0x15/0x20
[   34.689613]  task_work_run+0x199/0x270
[   34.693476]  ? task_work_cancel+0x210/0x210
[   34.697766]  ? free_nsproxy+0x185/0x1f0
[   34.701711]  ? switch_task_namespaces+0xa2/0xc0
[   34.706356]  do_exit+0x9d2/0x1af0
[   34.709779]  ? trace_hardirqs_on+0xd/0x10
[   34.713901]  ? mm_update_next_owner+0x930/0x930
[   34.718539]  ? mark_held_locks+0xb2/0x100
[   34.722659]  ? kfree+0xe4/0x250
[   34.725909]  ? kvfree+0x36/0x60
[   34.729160]  ? trace_hardirqs_on_caller+0x421/0x5c0
[   34.734149]  ? trace_hardirqs_on+0xd/0x10
[   34.738270]  ? kvfree+0x3b/0x60
[   34.741523]  ? rtnl_unlock+0xe/0x10
[   34.745122]  ? __tun_chr_ioctl+0x27a/0x3d20
[   34.749428]  ? find_held_lock+0x39/0x1d0
[   34.753464]  ? __might_sleep+0x95/0x190
[   34.757420]  ? selinux_file_ioctl+0x444/0x690
[   34.761884]  ? __fget_light+0x29d/0x390
[   34.765846]  ? handle_mm_fault+0x410/0x8d0
[   34.770058]  ? tun_chr_compat_ioctl+0x29/0x30
[   34.774523]  ? tun_chr_compat_ioctl+0x29/0x30
[   34.778992]  do_group_exit+0x149/0x400
[   34.782851]  ? __tun_chr_ioctl+0x3d20/0x3d20
[   34.787228]  ? SyS_exit+0x30/0x30
[   34.790652]  ? do_ioctl+0x60/0x60
[   34.794078]  ? do_fast_syscall_32+0x158/0xf05
[   34.798546]  ? do_group_exit+0x400/0x400
[   34.802576]  SyS_exit_group+0x1d/0x20
[   34.806348]  do_fast_syscall_32+0x3f2/0xf05
[   34.810648]  ? do_int80_syscall_32+0x940/0x940
[   34.815201]  ? trace_hardirqs_on_thunk+0x1a/0x1c
[   34.819932]  ? lockdep_sys_exit+0x47/0xf0
[   34.824050]  ? syscall_return_slowpath+0x2b3/0x510
[   34.828956]  ? sysret32_from_system_call+0x5/0x3b
[   34.833772]  ? trace_hardirqs_off_thunk+0x1a/0x1c
[   34.838589]  entry_SYSENTER_compat+0x51/0x60
[   34.842966] RIP: 0023:0xf7efec79
[   34.846299] RSP: 002b:00000000ffcfed6c EFLAGS: 00000282 ORIG_RAX: 00000000000000fc
[   34.853979] RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00000000ffcfef58
[   34.861219] RDX: 0000000008048d6c RSI: 0000000000000036 RDI: 0000000000000004
[   34.868459] RBP: 00000000400454ca R08: 0000000000000000 R09: 0000000000000000
[   34.875698] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
[   34.882940] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
[   34.890196] 
[   34.891793] Allocated by task 2986:
[   34.895394]  save_stack_trace+0x16/0x20
[   34.899336]  save_stack+0x43/0xd0
[   34.902760]  kasan_kmalloc+0xad/0xe0
[   34.906441]  __kmalloc_node+0x47/0x70
[   34.910210]  kvmalloc_node+0x64/0xd0
[   34.913893]  alloc_netdev_mqs+0x16e/0xed0
[   34.918007]  __tun_chr_ioctl+0x12be/0x3d20
[   34.922208]  tun_chr_compat_ioctl+0x29/0x30
[   34.926498]  compat_SyS_ioctl+0x1d7/0x3290
[   34.930701]  do_fast_syscall_32+0x3f2/0xf05
[   34.934988]  entry_SYSENTER_compat+0x51/0x60
[   34.939363] 
[   34.940959] Freed by task 2986:
[   34.944208]  save_stack_trace+0x16/0x20
[   34.948149]  save_stack+0x43/0xd0
[   34.951569]  kasan_slab_free+0x71/0xc0
[   34.955424]  kfree+0xca/0x250
[   34.958498]  kvfree+0x36/0x60
[   34.961573]  free_netdev+0x2cf/0x360
[   34.965257]  __tun_chr_ioctl+0x2cf6/0x3d20
[   34.969459]  tun_chr_compat_ioctl+0x29/0x30
[   34.973752]  compat_SyS_ioctl+0x1d7/0x3290
[   34.977971]  do_fast_syscall_32+0x3f2/0xf05
[   34.982263]  entry_SYSENTER_compat+0x51/0x60
[   34.986637] 
[   34.988235] The buggy address belongs to the object at ffff8801cff10380
[   34.988235]  which belongs to the cache kmalloc-16384 of size 16384
[   35.001208] The buggy address is located 13312 bytes inside of
[   35.001208]  16384-byte region [ffff8801cff10380, ffff8801cff14380)
[   35.013397] The buggy address belongs to the page:
[   35.018297] page:ffffea00073fc400 count:1 mapcount:0 mapping:ffff8801cff10380 index:0x0 compound_mapcount: 0
[   35.028241] flags: 0x200000000008100(slab|head)
[   35.032880] raw: 0200000000008100 ffff8801cff10380 0000000000000000 0000000100000001
[   35.040731] raw: ffffea000733fa20 ffff8801dac01c50 ffff8801dac02200 0000000000000000
[   35.048581] page dumped because: kasan: bad access detected
[   35.054258] 
[   35.055854] Memory state around the buggy address:
[   35.060752]  ffff8801cff13680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[   35.068080]  ffff8801cff13700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[   35.075410] >ffff8801cff13780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[   35.082741]                    ^
[   35.086077]  ffff8801cff13800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[   35.093405]  ffff8801cff13880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[   35.100732] ==================================================================
[   35.108060] Disabling lock debugging due to kernel taint
[   35.113472] Kernel panic - not syncing: panic_on_warn set ...
[   35.113472] 
[   35.120800] CPU: 0 PID: 2986 Comm: syzkaller995923 Tainted: G    B           4.14.0-rc3+ #23
[   35.129337] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
[   35.138655] Call Trace:
[   35.141213]  dump_stack+0x194/0x257
[   35.144808]  ? arch_local_irq_restore+0x53/0x53
[   35.149446]  ? vprintk_default+0x28/0x30
[   35.153476]  ? detach_if_pending+0x500/0x610
[   35.157850]  panic+0x1e4/0x417
[   35.161007]  ? __warn+0x1d9/0x1d9
[   35.164430]  ? detach_if_pending+0x557/0x610
[   35.168804]  kasan_end_report+0x50/0x50
[   35.172744]  kasan_report+0x144/0x340
[   35.176511]  __asan_report_store8_noabort+0x17/0x20
[   35.181491]  detach_if_pending+0x557/0x610
[   35.185692]  ? trace_raw_output_tick_stop+0x130/0x130
[   35.190847]  ? _raw_spin_lock_irqsave+0x9e/0xc0
[   35.195477]  ? lock_timer_base+0x1a3/0x2b0
[   35.199675]  ? lock_timer_base+0x1eb/0x2b0
[   35.203875]  ? __internal_add_timer+0x2d0/0x2d0
[   35.208511]  ? trace_hardirqs_on+0xd/0x10
[   35.212628]  try_to_del_timer_sync+0xa2/0x120
[   35.217087]  ? del_timer+0x130/0x130
[   35.220774]  ? del_timer_sync+0xeb/0x240
[   35.224807]  del_timer_sync+0x18a/0x240
[   35.228748]  tun_free_netdev+0x105/0x1b0
[   35.232774]  ? tun_xdp+0x410/0x410
[   35.236279]  ? cpumask_next+0x24/0x30
[   35.240044]  ? netdev_refcnt_read+0xed/0x150
[   35.244419]  ? tun_xdp+0x410/0x410
[   35.247922]  netdev_run_todo+0x870/0xca0
[   35.251947]  ? do_group_exit+0x149/0x400
[   35.255973]  ? register_netdev+0x30/0x30
[   35.260002]  ? lock_downgrade+0x990/0x990
[   35.264113]  ? trace_hardirqs_on+0xd/0x10
[   35.268240]  ? refcount_sub_and_test+0x115/0x1b0
[   35.272959]  ? refcount_inc+0x50/0x50
[   35.276724]  ? refcount_inc+0x50/0x50
[   35.280493]  ? sk_destruct+0x4c/0x80
[   35.284171]  ? __sk_free+0x5c/0x230
[   35.287762]  ? sk_free+0x2f/0x40
[   35.291093]  ? __tun_detach+0x176/0x1390
[   35.295125]  ? tun_attach+0xf90/0xf90
[   35.298894]  ? locks_remove_file+0x3fa/0x5a0
[   35.303268]  ? fcntl_setlk+0x10d0/0x10d0
[   35.307305]  ? __fsnotify_parent+0xb4/0x3a0
[   35.311592]  ? fsnotify+0x1af0/0x1af0
[   35.315363]  ? __tun_detach+0x1390/0x1390
[   35.319475]  ? __tun_detach+0x1390/0x1390
[   35.323588]  rtnl_unlock+0xe/0x10
[   35.327005]  tun_chr_close+0x49/0x60
[   35.330684]  __fput+0x333/0x7f0
[   35.333932]  ? fput+0x140/0x140
[   35.337179]  ? check_same_owner+0x320/0x320
[   35.341470]  ____fput+0x15/0x20
[   35.344716]  task_work_run+0x199/0x270
[   35.348570]  ? task_work_cancel+0x210/0x210
[   35.352855]  ? free_nsproxy+0x185/0x1f0
[   35.356795]  ? switch_task_namespaces+0xa2/0xc0
[   35.361428]  do_exit+0x9d2/0x1af0
[   35.364847]  ? trace_hardirqs_on+0xd/0x10
[   35.368960]  ? mm_update_next_owner+0x930/0x930
[   35.373591]  ? mark_held_locks+0xb2/0x100
[   35.377707]  ? kfree+0xe4/0x250
[   35.380957]  ? kvfree+0x36/0x60
[   35.384207]  ? trace_hardirqs_on_caller+0x421/0x5c0
[   35.389195]  ? trace_hardirqs_on+0xd/0x10
[   35.393315]  ? kvfree+0x3b/0x60
[   35.396563]  ? rtnl_unlock+0xe/0x10
[   35.400156]  ? __tun_chr_ioctl+0x27a/0x3d20
[   35.404453]  ? find_held_lock+0x39/0x1d0
[   35.408481]  ? __might_sleep+0x95/0x190
[   35.412427]  ? selinux_file_ioctl+0x444/0x690
[   35.416886]  ? __fget_light+0x29d/0x390
[   35.420833]  ? handle_mm_fault+0x410/0x8d0
[   35.425035]  ? tun_chr_compat_ioctl+0x29/0x30
[   35.429495]  ? tun_chr_compat_ioctl+0x29/0x30
[   35.433985]  do_group_exit+0x149/0x400
[   35.437845]  ? __tun_chr_ioctl+0x3d20/0x3d20
[   35.442217]  ? SyS_exit+0x30/0x30
[   35.445645]  ? do_ioctl+0x60/0x60