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-386-0,10.128.15.209' (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: [   44.509386] ==================================================================
[   44.516854] BUG: KASAN: use-after-free in detach_if_pending+0x557/0x610
[   44.523582] Write of size 8 at addr ffff8801cc983740 by task syzkaller880522/2989
[   44.531172] 
[   44.532778] CPU: 1 PID: 2989 Comm: syzkaller880522 Not tainted 4.14.0-rc2+ #19
[   44.540110] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
[   44.549438] Call Trace:
[   44.552002]  dump_stack+0x194/0x257
[   44.555607]  ? arch_local_irq_restore+0x53/0x53
[   44.560248]  ? show_regs_print_info+0x65/0x65
[   44.564718]  ? lock_timer_base+0x1a3/0x2b0
[   44.568930]  ? detach_if_pending+0x557/0x610
[   44.573320]  print_address_description+0x73/0x250
[   44.578139]  ? detach_if_pending+0x557/0x610
[   44.582524]  kasan_report+0x25b/0x340
[   44.586300]  __asan_report_store8_noabort+0x17/0x20
[   44.591287]  detach_if_pending+0x557/0x610
[   44.595510]  ? trace_raw_output_tick_stop+0x130/0x130
[   44.600674]  ? _raw_spin_lock_irqsave+0x9e/0xc0
[   44.605313]  ? lock_timer_base+0x1a3/0x2b0
[   44.609519]  ? lock_timer_base+0x1eb/0x2b0
[   44.613734]  ? __internal_add_timer+0x2d0/0x2d0
[   44.618380]  ? trace_hardirqs_on+0xd/0x10
[   44.622508]  try_to_del_timer_sync+0xa2/0x120
[   44.626977]  ? del_timer+0x130/0x130
[   44.630668]  ? del_timer_sync+0xeb/0x240
[   44.634711]  del_timer_sync+0x18a/0x240
[   44.638662]  tun_free_netdev+0x105/0x1b0
[   44.642698]  ? tun_xdp+0x410/0x410
[   44.646213]  ? cpumask_next+0x24/0x30
[   44.649994]  ? netdev_refcnt_read+0xed/0x150
[   44.654379]  ? tun_xdp+0x410/0x410
[   44.657892]  netdev_run_todo+0x870/0xca0
[   44.661929]  ? do_group_exit+0x149/0x400
[   44.665981]  ? register_netdev+0x30/0x30
[   44.670022]  ? lock_downgrade+0x990/0x990
[   44.674144]  ? trace_hardirqs_on+0xd/0x10
[   44.678289]  ? refcount_sub_and_test+0x115/0x1b0
[   44.683022]  ? refcount_inc+0x50/0x50
[   44.686796]  ? refcount_inc+0x50/0x50
[   44.690577]  ? sk_destruct+0x4c/0x80
[   44.694264]  ? __sk_free+0x5c/0x230
[   44.697868]  ? sk_free+0x2f/0x40
[   44.701209]  ? __tun_detach+0x176/0x1390
[   44.705257]  ? tun_attach+0xf90/0xf90
[   44.709044]  ? locks_remove_file+0x3fa/0x5a0
[   44.713429]  ? fcntl_setlk+0x10d0/0x10d0
[   44.717466]  ? __fsnotify_parent+0xb4/0x3a0
[   44.721762]  ? fsnotify+0x1af0/0x1af0
[   44.725539]  ? __tun_detach+0x1390/0x1390
[   44.729659]  ? __tun_detach+0x1390/0x1390
[   44.733780]  rtnl_unlock+0xe/0x10
[   44.737204]  tun_chr_close+0x49/0x60
[   44.740893]  __fput+0x333/0x7f0
[   44.744151]  ? fput+0x140/0x140
[   44.747405]  ? check_same_owner+0x320/0x320
[   44.751704]  ____fput+0x15/0x20
[   44.754957]  task_work_run+0x199/0x270
[   44.758823]  ? task_work_cancel+0x210/0x210
[   44.763117]  ? free_nsproxy+0x185/0x1f0
[   44.767070]  ? switch_task_namespaces+0xa2/0xc0
[   44.771716]  do_exit+0x9d2/0x1af0
[   44.775142]  ? trace_hardirqs_on+0xd/0x10
[   44.779266]  ? mm_update_next_owner+0x930/0x930
[   44.783906]  ? mark_held_locks+0xb2/0x100
[   44.788028]  ? kfree+0xe4/0x250
[   44.791276]  ? kvfree+0x36/0x60
[   44.794527]  ? trace_hardirqs_on_caller+0x421/0x5c0
[   44.799515]  ? trace_hardirqs_on+0xd/0x10
[   44.803637]  ? kvfree+0x3b/0x60
[   44.806897]  ? rtnl_unlock+0xe/0x10
[   44.810495]  ? __tun_chr_ioctl+0x27a/0x3d20
[   44.814892]  ? __pmd_alloc+0x4e0/0x4e0
[   44.818755]  ? __might_sleep+0x95/0x190
[   44.822710]  ? selinux_file_ioctl+0x444/0x690
[   44.827175]  ? __fget_light+0x29d/0x390
[   44.831146]  ? tun_chr_compat_ioctl+0x29/0x30
[   44.835614]  ? tun_chr_compat_ioctl+0x29/0x30
[   44.840083]  do_group_exit+0x149/0x400
[   44.843938]  ? __handle_mm_fault+0x39c0/0x39c0
[   44.848487]  ? __tun_chr_ioctl+0x3d20/0x3d20
[   44.852867]  ? SyS_exit+0x30/0x30
[   44.856294]  ? do_ioctl+0x60/0x60
[   44.859724]  ? do_fast_syscall_32+0x158/0xf05
[   44.864190]  ? do_group_exit+0x400/0x400
[   44.868221]  SyS_exit_group+0x1d/0x20
[   44.871994]  do_fast_syscall_32+0x3f2/0xf05
[   44.876295]  ? do_int80_syscall_32+0x940/0x940
[   44.880849]  ? trace_hardirqs_on_thunk+0x1a/0x1c
[   44.885579]  ? lockdep_sys_exit+0x47/0xf0
[   44.889700]  ? syscall_return_slowpath+0x2b3/0x510
[   44.894608]  ? sysret32_from_system_call+0x5/0x3b
[   44.899426]  ? trace_hardirqs_off_thunk+0x1a/0x1c
[   44.904246]  entry_SYSENTER_compat+0x51/0x60
[   44.908624] RIP: 0023:0xf7efec79
[   44.911958] RSP: 002b:00000000ff97014c EFLAGS: 00000286 ORIG_RAX: 00000000000000fc
[   44.919639] RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00000000ff970338
[   44.926881] RDX: 0000000008048e5f RSI: 0000000000000036 RDI: 0000000000000004
[   44.934126] RBP: 00000000400454ca R08: 0000000000000000 R09: 0000000000000000
[   44.941366] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
[   44.948606] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
[   44.955867] 
[   44.957467] Allocated by task 2989:
[   44.961067]  save_stack_trace+0x16/0x20
[   44.965012]  save_stack+0x43/0xd0
[   44.968437]  kasan_kmalloc+0xad/0xe0
[   44.972122]  __kmalloc_node+0x47/0x70
[   44.975892]  kvmalloc_node+0x64/0xd0
[   44.979579]  alloc_netdev_mqs+0x16e/0xed0
[   44.983697]  __tun_chr_ioctl+0x12be/0x3d20
[   44.987902]  tun_chr_compat_ioctl+0x29/0x30
[   44.992195]  compat_SyS_ioctl+0x1d7/0x3290
[   44.996399]  do_fast_syscall_32+0x3f2/0xf05
[   45.000691]  entry_SYSENTER_compat+0x51/0x60
[   45.005068] 
[   45.006667] Freed by task 2989:
[   45.009921]  save_stack_trace+0x16/0x20
[   45.013866]  save_stack+0x43/0xd0
[   45.017292]  kasan_slab_free+0x71/0xc0
[   45.021149]  kfree+0xca/0x250
[   45.024228]  kvfree+0x36/0x60
[   45.027307]  free_netdev+0x2cf/0x360
[   45.030989]  __tun_chr_ioctl+0x2cf6/0x3d20
[   45.035192]  tun_chr_compat_ioctl+0x29/0x30
[   45.039484]  compat_SyS_ioctl+0x1d7/0x3290
[   45.043691]  do_fast_syscall_32+0x3f2/0xf05
[   45.047984]  entry_SYSENTER_compat+0x51/0x60
[   45.052359] 
[   45.053962] The buggy address belongs to the object at ffff8801cc980340
[   45.053962]  which belongs to the cache kmalloc-16384 of size 16384
[   45.066937] The buggy address is located 13312 bytes inside of
[   45.066937]  16384-byte region [ffff8801cc980340, ffff8801cc984340)
[   45.079129] The buggy address belongs to the page:
[   45.084033] page:ffffea0007326000 count:1 mapcount:0 mapping:ffff8801cc980340 index:0x0 compound_mapcount: 0
[   45.093982] flags: 0x200000000008100(slab|head)
[   45.098624] raw: 0200000000008100 ffff8801cc980340 0000000000000000 0000000100000001
[   45.106477] raw: ffffea0007363820 ffff8801dac01c50 ffff8801dac02200 0000000000000000
[   45.114323] page dumped because: kasan: bad access detected
[   45.120003] 
[   45.121602] Memory state around the buggy address:
[   45.126502]  ffff8801cc983600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[   45.133831]  ffff8801cc983680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[   45.141163] >ffff8801cc983700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[   45.148493]                                            ^
[   45.153913]  ffff8801cc983780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[   45.161244]  ffff8801cc983800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[   45.168572] ==================================================================
[   45.175900] Disabling lock debugging due to kernel taint
[   45.181314] Kernel panic - not syncing: panic_on_warn set ...
[   45.181314] 
[   45.188642] CPU: 1 PID: 2989 Comm: syzkaller880522 Tainted: G    B           4.14.0-rc2+ #19
[   45.197180] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
[   45.206500] Call Trace:
[   45.209061]  dump_stack+0x194/0x257
[   45.212655]  ? arch_local_irq_restore+0x53/0x53
[   45.217293]  ? vprintk_default+0x28/0x30
[   45.221326]  ? detach_if_pending+0x4d0/0x610
[   45.225703]  panic+0x1e4/0x417
[   45.228864]  ? __warn+0x1d9/0x1d9
[   45.232292]  ? detach_if_pending+0x557/0x610
[   45.236667]  kasan_end_report+0x50/0x50
[   45.240607]  kasan_report+0x144/0x340
[   45.244375]  __asan_report_store8_noabort+0x17/0x20
[   45.249355]  detach_if_pending+0x557/0x610
[   45.253555]  ? trace_raw_output_tick_stop+0x130/0x130
[   45.258712]  ? _raw_spin_lock_irqsave+0x9e/0xc0
[   45.263344]  ? lock_timer_base+0x1a3/0x2b0
[   45.267543]  ? lock_timer_base+0x1eb/0x2b0
[   45.271745]  ? __internal_add_timer+0x2d0/0x2d0
[   45.276382]  ? trace_hardirqs_on+0xd/0x10
[   45.280498]  try_to_del_timer_sync+0xa2/0x120
[   45.284959]  ? del_timer+0x130/0x130
[   45.288639]  ? del_timer_sync+0xeb/0x240
[   45.292666]  del_timer_sync+0x18a/0x240
[   45.296608]  tun_free_netdev+0x105/0x1b0
[   45.300634]  ? tun_xdp+0x410/0x410
[   45.304139]  ? cpumask_next+0x24/0x30
[   45.307919]  ? netdev_refcnt_read+0xed/0x150
[   45.312298]  ? tun_xdp+0x410/0x410
[   45.315809]  netdev_run_todo+0x870/0xca0
[   45.319842]  ? do_group_exit+0x149/0x400
[   45.323880]  ? register_netdev+0x30/0x30
[   45.327916]  ? lock_downgrade+0x990/0x990
[   45.332034]  ? trace_hardirqs_on+0xd/0x10
[   45.336160]  ? refcount_sub_and_test+0x115/0x1b0
[   45.340881]  ? refcount_inc+0x50/0x50
[   45.344648]  ? refcount_inc+0x50/0x50
[   45.348418]  ? sk_destruct+0x4c/0x80
[   45.352098]  ? __sk_free+0x5c/0x230
[   45.355690]  ? sk_free+0x2f/0x40
[   45.359022]  ? __tun_detach+0x176/0x1390
[   45.363052]  ? tun_attach+0xf90/0xf90
[   45.366825]  ? locks_remove_file+0x3fa/0x5a0
[   45.371198]  ? fcntl_setlk+0x10d0/0x10d0
[   45.375230]  ? __fsnotify_parent+0xb4/0x3a0
[   45.379517]  ? fsnotify+0x1af0/0x1af0
[   45.383286]  ? __tun_detach+0x1390/0x1390
[   45.387400]  ? __tun_detach+0x1390/0x1390
[   45.391514]  rtnl_unlock+0xe/0x10
[   45.394935]  tun_chr_close+0x49/0x60
[   45.398626]  __fput+0x333/0x7f0
[   45.401874]  ? fput+0x140/0x140
[   45.405122]  ? check_same_owner+0x320/0x320
[   45.409411]  ____fput+0x15/0x20
[   45.412659]  task_work_run+0x199/0x270
[   45.416513]  ? task_work_cancel+0x210/0x210
[   45.420803]  ? free_nsproxy+0x185/0x1f0
[   45.424742]  ? switch_task_namespaces+0xa2/0xc0
[   45.429377]  do_exit+0x9d2/0x1af0
[   45.432797]  ? trace_hardirqs_on+0xd/0x10
[   45.436913]  ? mm_update_next_owner+0x930/0x930
[   45.441548]  ? mark_held_locks+0xb2/0x100
[   45.445664]  ? kfree+0xe4/0x250
[   45.448914]  ? kvfree+0x36/0x60
[   45.452160]  ? trace_hardirqs_on_caller+0x421/0x5c0
[   45.457140]  ? trace_hardirqs_on+0xd/0x10
[   45.461254]  ? kvfree+0x3b/0x60
[   45.464504]  ? rtnl_unlock+0xe/0x10
[   45.468097]  ? __tun_chr_ioctl+0x27a/0x3d20
[   45.472393]  ? __pmd_alloc+0x4e0/0x4e0
[   45.476248]  ? __might_sleep+0x95/0x190
[   45.480193]  ? selinux_file_ioctl+0x444/0x690
[   45.484654]  ? __fget_light+0x29d/0x390
[   45.488605]  ? tun_chr_compat_ioctl+0x29/0x30
[   45.493063]  ? tun_chr_compat_ioctl+0x29/0x30
[   45.497524]  do_group_exit+0x149/0x400
[   45.501384]  ? __handle_mm_fault+0x39c0/0x39c0
[   45.505932]  ? __tun_chr_ioctl+0x3d20/0x3d20
[   45.510305]  ? SyS_exit+0x30/0x30