[....] 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.
[   28.894864] kauditd_printk_skb: 8 callbacks suppressed
[   28.894876] audit: type=1800 audit(1544583101.742:29): pid=5896 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="rc.local" dev="sda1" ino=2432 res=0
[   28.929127] audit: type=1800 audit(1544583101.742:30): pid=5896 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="rmnologin" dev="sda1" ino=2423 res=0

Debian GNU/Linux 7 syzkaller ttyS0

syzkaller login: [   33.273688] sshd (6035) used greatest stack depth: 15744 bytes left
Warning: Permanently added '10.128.0.91' (ECDSA) to the list of known hosts.
executing program
[   40.089598] ==================================================================
[   40.097154] BUG: KASAN: use-after-free in tipc_group_bc_cong+0x327/0x3f0
[   40.103977] Read of size 2 at addr ffff8881d8431b74 by task syz-executor877/6054
[   40.111494] 
[   40.113112] CPU: 0 PID: 6054 Comm: syz-executor877 Not tainted 4.20.0-rc6+ #371
[   40.120533] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
[   40.129865] Call Trace:
[   40.132439]  dump_stack+0x244/0x39d
[   40.136057]  ? dump_stack_print_info.cold.1+0x20/0x20
[   40.141236]  ? printk+0xa7/0xcf
[   40.144501]  ? kmsg_dump_rewind_nolock+0xe4/0xe4
[   40.149248]  ? _raw_spin_unlock_irqrestore+0x82/0xd0
[   40.154343]  print_address_description.cold.7+0x9/0x1ff
[   40.159691]  kasan_report.cold.8+0x242/0x309
[   40.164085]  ? tipc_group_bc_cong+0x327/0x3f0
[   40.168588]  __asan_report_load2_noabort+0x14/0x20
[   40.173504]  tipc_group_bc_cong+0x327/0x3f0
[   40.177808]  ? _raw_spin_unlock_irqrestore+0x6d/0xd0
[   40.182896]  ? tipc_group_cong+0x5d0/0x5d0
[   40.187123]  ? remove_wait_queue+0x1a6/0x360
[   40.191539]  ? add_wait_queue+0x2b0/0x2b0
[   40.195676]  ? __local_bh_enable_ip+0x160/0x260
[   40.200347]  tipc_send_group_bcast+0x50a/0xd90
[   40.204941]  ? tipc_sk_sock_err.isra.61+0x2f0/0x2f0
[   40.209989]  ? __init_waitqueue_head+0x150/0x150
[   40.214735]  ? refill_pi_state_cache.part.8+0x310/0x310
[   40.220089]  ? mark_held_locks+0x130/0x130
[   40.224311]  ? futex_wait_setup+0x266/0x3e0
[   40.228635]  ? futex_wake+0x760/0x760
[   40.232443]  ? print_usage_bug+0xc0/0xc0
[   40.236510]  ? __sanitizer_cov_trace_switch+0x53/0x90
[   40.241711]  __tipc_sendmsg+0xeec/0x1d40
[   40.245762]  ? futex_wait+0x5ec/0xa50
[   40.249554]  ? tipc_sendmcast+0xf50/0xf50
[   40.253688]  ? __sanitizer_cov_trace_switch+0x53/0x90
[   40.258864]  ? zap_class+0x640/0x640
[   40.262581]  ? print_usage_bug+0xc0/0xc0
[   40.266631]  ? find_held_lock+0x36/0x1c0
[   40.270675]  ? mark_held_locks+0xc7/0x130
[   40.274809]  ? __local_bh_enable_ip+0x160/0x260
[   40.279460]  ? __local_bh_enable_ip+0x160/0x260
[   40.284119]  ? lockdep_hardirqs_on+0x3bb/0x5b0
[   40.288699]  ? trace_hardirqs_on+0xbd/0x310
[   40.293006]  ? lock_release+0xa00/0xa00
[   40.296964]  ? lock_sock_nested+0xe2/0x120
[   40.301183]  ? trace_hardirqs_off_caller+0x310/0x310
[   40.306278]  ? __sanitizer_cov_trace_const_cmp4+0x16/0x20
[   40.311802]  ? check_preemption_disabled+0x48/0x280
[   40.316814]  ? lock_sock_nested+0x9a/0x120
[   40.321036]  ? lock_sock_nested+0x9a/0x120
[   40.325260]  ? __local_bh_enable_ip+0x160/0x260
[   40.329918]  tipc_sendmsg+0x50/0x70
[   40.333532]  ? __tipc_sendmsg+0x1d40/0x1d40
[   40.337845]  sock_sendmsg+0xd5/0x120
[   40.341544]  ___sys_sendmsg+0x7fd/0x930
[   40.345505]  ? find_held_lock+0x36/0x1c0
[   40.349552]  ? copy_msghdr_from_user+0x580/0x580
[   40.354297]  ? __fd_install+0x2b5/0x8f0
[   40.358262]  ? check_preemption_disabled+0x48/0x280
[   40.363274]  ? __fget_light+0x2e9/0x430
[   40.367233]  ? fget_raw+0x20/0x20
[   40.370672]  ? __sanitizer_cov_trace_const_cmp4+0x16/0x20
[   40.376203]  ? __fd_install+0x2f9/0x8f0
[   40.380171]  ? get_unused_fd_flags+0x1a0/0x1a0
[   40.384758]  ? __sanitizer_cov_trace_const_cmp8+0x18/0x20
[   40.390297]  ? sockfd_lookup_light+0xc5/0x160
[   40.394797]  __sys_sendmsg+0x11d/0x280
[   40.398700]  ? __ia32_sys_shutdown+0x80/0x80
[   40.403099]  ? __x64_sys_futex+0x47f/0x6a0
[   40.407352]  ? do_syscall_64+0x9a/0x820
[   40.411325]  ? do_syscall_64+0x9a/0x820
[   40.415291]  ? trace_hardirqs_off_caller+0x310/0x310
[   40.420381]  __x64_sys_sendmsg+0x78/0xb0
[   40.424427]  do_syscall_64+0x1b9/0x820
[   40.428296]  ? entry_SYSCALL_64_after_hwframe+0x3e/0xbe
[   40.433644]  ? syscall_return_slowpath+0x5e0/0x5e0
[   40.438570]  ? trace_hardirqs_on_caller+0x310/0x310
[   40.443580]  ? prepare_exit_to_usermode+0x3b0/0x3b0
[   40.448582]  ? post_copy_siginfo_from_user.isra.25.part.26+0x250/0x250
[   40.455237]  ? __switch_to_asm+0x40/0x70
[   40.459294]  ? __switch_to_asm+0x34/0x70
[   40.463342]  ? trace_hardirqs_off_thunk+0x1a/0x1c
[   40.468171]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
[   40.473428] RIP: 0033:0x446389
[   40.476617] Code: e8 2c b3 02 00 48 83 c4 18 c3 0f 1f 80 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 2b 09 fc ff c3 66 2e 0f 1f 84 00 00 00 00
[   40.495521] RSP: 002b:00007f98a0791db8 EFLAGS: 00000297 ORIG_RAX: 000000000000002e
[   40.503215] RAX: ffffffffffffffda RBX: 00000000006dac38 RCX: 0000000000446389
[   40.510467] RDX: 0000000000000000 RSI: 00000000200006c0 RDI: 0000000000000005
[   40.517719] RBP: 00000000006dac30 R08: 0000000000000000 R09: 0000000000000000
[   40.524966] R10: 0000000000000000 R11: 0000000000000297 R12: 00000000006dac3c
[   40.532221] R13: 00007ffd267944ff R14: 00007f98a07929c0 R15: 00000000006dad2c
[   40.539499] 
[   40.541109] Allocated by task 6055:
[   40.544735]  save_stack+0x43/0xd0
[   40.548185]  kasan_kmalloc+0xc7/0xe0
[   40.551889]  kmem_cache_alloc_trace+0x152/0x750
[   40.556542]  tipc_group_create+0x152/0xa70
[   40.560758]  tipc_setsockopt+0x2d1/0xd70
[   40.564801]  __sys_setsockopt+0x1ba/0x3c0
[   40.568948]  __x64_sys_setsockopt+0xbe/0x150
[   40.573343]  do_syscall_64+0x1b9/0x820
[   40.577217]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
[   40.582381] 
[   40.583988] Freed by task 6055:
[   40.587247]  save_stack+0x43/0xd0
[   40.590680]  __kasan_slab_free+0x102/0x150
[   40.594937]  kasan_slab_free+0xe/0x10
[   40.598748]  kfree+0xcf/0x230
[   40.601846]  tipc_group_delete+0x2e4/0x3f0
[   40.606069]  tipc_sk_leave+0x113/0x220
[   40.609939]  tipc_setsockopt+0x97d/0xd70
[   40.613985]  __sys_setsockopt+0x1ba/0x3c0
[   40.618115]  __x64_sys_setsockopt+0xbe/0x150
[   40.622507]  do_syscall_64+0x1b9/0x820
[   40.626380]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
[   40.631545] 
[   40.633182] The buggy address belongs to the object at ffff8881d8431b00
[   40.633182]  which belongs to the cache kmalloc-192 of size 192
[   40.645823] The buggy address is located 116 bytes inside of
[   40.645823]  192-byte region [ffff8881d8431b00, ffff8881d8431bc0)
[   40.657675] The buggy address belongs to the page:
[   40.662596] page:ffffea0007610c40 count:1 mapcount:0 mapping:ffff8881da800040 index:0xffff8881d8431100
[   40.672040] flags: 0x2fffc0000000200(slab)
[   40.676263] raw: 02fffc0000000200 ffffea0007143848 ffffea0007143588 ffff8881da800040
[   40.684149] raw: ffff8881d8431100 ffff8881d8431000 0000000100000008 0000000000000000
[   40.692029] page dumped because: kasan: bad access detected
[   40.697719] 
[   40.699328] Memory state around the buggy address:
[   40.704248]  ffff8881d8431a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[   40.711601]  ffff8881d8431a80: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
[   40.718941] >ffff8881d8431b00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[   40.726280]                                                              ^
[   40.733273]  ffff8881d8431b80: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
[   40.740613]  ffff8881d8431c00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[   40.747948] ==================================================================
[   40.755286] Disabling lock debugging due to kernel taint
[   40.763985] Kernel panic - not syncing: panic_on_warn set ...
[   40.768923] kobject: 'regulatory.0' (000000004600c816): kobject_uevent_env
[   40.769875] CPU: 0 PID: 6054 Comm: syz-executor877 Tainted: G    B             4.20.0-rc6+ #371
[   40.776885] kobject: 'regulatory.0' (000000004600c816): fill_kobj_path: path = '/devices/platform/regulatory.0'
[   40.785688] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
[   40.785693] Call Trace:
[   40.785715]  dump_stack+0x244/0x39d
[   40.785733]  ? dump_stack_print_info.cold.1+0x20/0x20
[   40.816628]  panic+0x2ad/0x55c
[   40.819805]  ? add_taint.cold.5+0x16/0x16
[   40.823980]  ? preempt_schedule+0x4d/0x60
[   40.828148]  ? ___preempt_schedule+0x16/0x18
[   40.832545]  ? trace_hardirqs_on+0xb4/0x310
[   40.836855]  kasan_end_report+0x47/0x4f
[   40.840808]  kasan_report.cold.8+0x76/0x309
[   40.845217]  ? tipc_group_bc_cong+0x327/0x3f0
[   40.849697]  __asan_report_load2_noabort+0x14/0x20
[   40.854616]  tipc_group_bc_cong+0x327/0x3f0
[   40.858929]  ? _raw_spin_unlock_irqrestore+0x6d/0xd0
[   40.864034]  ? tipc_group_cong+0x5d0/0x5d0
[   40.868253]  ? remove_wait_queue+0x1a6/0x360
[   40.872643]  ? add_wait_queue+0x2b0/0x2b0
[   40.876774]  ? __local_bh_enable_ip+0x160/0x260
[   40.881425]  tipc_send_group_bcast+0x50a/0xd90
[   40.886010]  ? tipc_sk_sock_err.isra.61+0x2f0/0x2f0
[   40.891192]  ? __init_waitqueue_head+0x150/0x150
[   40.895967]  ? refill_pi_state_cache.part.8+0x310/0x310
[   40.901334]  ? mark_held_locks+0x130/0x130
[   40.905559]  ? futex_wait_setup+0x266/0x3e0
[   40.909975]  ? futex_wake+0x760/0x760
[   40.913775]  ? print_usage_bug+0xc0/0xc0
[   40.917824]  ? __sanitizer_cov_trace_switch+0x53/0x90
[   40.922998]  __tipc_sendmsg+0xeec/0x1d40
[   40.927044]  ? futex_wait+0x5ec/0xa50
[   40.930839]  ? tipc_sendmcast+0xf50/0xf50
[   40.934991]  ? __sanitizer_cov_trace_switch+0x53/0x90
[   40.940176]  ? zap_class+0x640/0x640
[   40.943875]  ? print_usage_bug+0xc0/0xc0
[   40.947938]  ? find_held_lock+0x36/0x1c0
[   40.952007]  ? mark_held_locks+0xc7/0x130
[   40.956136]  ? __local_bh_enable_ip+0x160/0x260
[   40.960786]  ? __local_bh_enable_ip+0x160/0x260
[   40.965438]  ? lockdep_hardirqs_on+0x3bb/0x5b0
[   40.970005]  ? trace_hardirqs_on+0xbd/0x310
[   40.974310]  ? lock_release+0xa00/0xa00
[   40.978267]  ? lock_sock_nested+0xe2/0x120
[   40.982495]  ? trace_hardirqs_off_caller+0x310/0x310
[   40.987582]  ? __sanitizer_cov_trace_const_cmp4+0x16/0x20
[   40.993104]  ? check_preemption_disabled+0x48/0x280
[   40.998101]  ? lock_sock_nested+0x9a/0x120
[   41.002323]  ? lock_sock_nested+0x9a/0x120
[   41.006547]  ? __local_bh_enable_ip+0x160/0x260
[   41.011203]  tipc_sendmsg+0x50/0x70
[   41.014820]  ? __tipc_sendmsg+0x1d40/0x1d40
[   41.019131]  sock_sendmsg+0xd5/0x120
[   41.022840]  ___sys_sendmsg+0x7fd/0x930
[   41.026799]  ? find_held_lock+0x36/0x1c0
[   41.030858]  ? copy_msghdr_from_user+0x580/0x580
[   41.035602]  ? __fd_install+0x2b5/0x8f0
[   41.039578]  ? check_preemption_disabled+0x48/0x280
[   41.044583]  ? __fget_light+0x2e9/0x430
[   41.048540]  ? fget_raw+0x20/0x20
[   41.052025]  ? __sanitizer_cov_trace_const_cmp4+0x16/0x20
[   41.057550]  ? __fd_install+0x2f9/0x8f0
[   41.061507]  ? get_unused_fd_flags+0x1a0/0x1a0
[   41.066075]  ? __sanitizer_cov_trace_const_cmp8+0x18/0x20
[   41.071599]  ? sockfd_lookup_light+0xc5/0x160
[   41.076081]  __sys_sendmsg+0x11d/0x280
[   41.079981]  ? __ia32_sys_shutdown+0x80/0x80
[   41.084400]  ? __x64_sys_futex+0x47f/0x6a0
[   41.088637]  ? do_syscall_64+0x9a/0x820
[   41.092603]  ? do_syscall_64+0x9a/0x820
[   41.096565]  ? trace_hardirqs_off_caller+0x310/0x310
[   41.101652]  __x64_sys_sendmsg+0x78/0xb0
[   41.105697]  do_syscall_64+0x1b9/0x820
[   41.109564]  ? entry_SYSCALL_64_after_hwframe+0x3e/0xbe
[   41.114904]  ? syscall_return_slowpath+0x5e0/0x5e0
[   41.119811]  ? trace_hardirqs_on_caller+0x310/0x310
[   41.124803]  ? prepare_exit_to_usermode+0x3b0/0x3b0
[   41.129798]  ? post_copy_siginfo_from_user.isra.25.part.26+0x250/0x250
[   41.136445]  ? __switch_to_asm+0x40/0x70
[   41.140493]  ? __switch_to_asm+0x34/0x70
[   41.144541]  ? trace_hardirqs_off_thunk+0x1a/0x1c
[   41.149364]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
[   41.154544] RIP: 0033:0x446389
[   41.157718] Code: e8 2c b3 02 00 48 83 c4 18 c3 0f 1f 80 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 2b 09 fc ff c3 66 2e 0f 1f 84 00 00 00 00
[   41.176602] RSP: 002b:00007f98a0791db8 EFLAGS: 00000297 ORIG_RAX: 000000000000002e
[   41.184339] RAX: ffffffffffffffda RBX: 00000000006dac38 RCX: 0000000000446389
[   41.191678] RDX: 0000000000000000 RSI: 00000000200006c0 RDI: 0000000000000005
[   41.198926] RBP: 00000000006dac30 R08: 0000000000000000 R09: 0000000000000000
[   41.206173] R10: 0000000000000000 R11: 0000000000000297 R12: 00000000006dac3c
[   41.213426] R13: 00007ffd267944ff R14: 00007f98a07929c0 R15: 00000000006dad2c
[   41.221624] Kernel Offset: disabled
[   41.225267] Rebooting in 86400 seconds..