[ 43.002998][ T27] audit: type=1800 audit(1576365127.157:22): pid=7633 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="motd" dev="sda1" ino=2480 res=0 [....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 43.824401][ T7707] cron (7707) used greatest stack depth: 10152 bytes left [....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [ 44.113212][ T7709] sshd (7709) used greatest stack depth: 10136 bytes left [....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 Warning: Permanently added '10.128.0.10' (ECDSA) to the list of known hosts. 2019/12/14 23:12:18 fuzzer started 2019/12/14 23:12:20 dialing manager at 10.128.0.105:44249 2019/12/14 23:12:20 syscalls: 2686 2019/12/14 23:12:20 code coverage: enabled 2019/12/14 23:12:20 comparison tracing: enabled 2019/12/14 23:12:20 extra coverage: enabled 2019/12/14 23:12:20 setuid sandbox: enabled 2019/12/14 23:12:20 namespace sandbox: enabled 2019/12/14 23:12:20 Android sandbox: /sys/fs/selinux/policy does not exist 2019/12/14 23:12:20 fault injection: enabled 2019/12/14 23:12:20 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/12/14 23:12:20 net packet injection: enabled 2019/12/14 23:12:20 net device setup: enabled 2019/12/14 23:12:20 concurrency sanitizer: enabled 2019/12/14 23:12:20 devlink PCI setup: PCI device 0000:00:10.0 is not available syzkaller login: [ 58.062128][ T7795] KCSAN: could not find function: 'poll_schedule_timeout' 2019/12/14 23:12:30 adding functions to KCSAN blacklist: '__hrtimer_run_queues' 'echo_char' 'enqueue_timer' 'commit_echoes' 'pid_update_inode' 'rcu_gp_fqs_loop' 'poll_schedule_timeout' 'ext4_free_inode' 'iomap_dio_bio_actor' 'ext4_mark_iloc_dirty' 'tick_sched_do_timer' 'yama_ptracer_del' 'audit_log_start' 'ext4_nonda_switch' 'pcpu_alloc' 'atime_needs_update' 'iput' 'ext4_has_free_clusters' 'generic_fillattr' 'do_signal_stop' 'wbt_done' 'tomoyo_supervisor' 'sit_tunnel_xmit' 'blk_mq_dispatch_rq_list' 'lruvec_lru_size' '__delete_from_page_cache' 'kauditd_thread' 'rcu_gp_fqs_check_wake' 'schedule_hrtimeout_range_clock' 'do_readlinkat' 'add_timer_on' 'run_timer_softirq' 'kcm_rfree' 'ep_poll' 'tick_nohz_idle_stop_tick' 'blk_mq_sched_dispatch_requests' '__dentry_kill' 'futex_wait_queue_me' 'generic_write_end' 'n_tty_receive_buf_common' 'wbt_wait' 'do_try_to_free_pages' 'add_timer' 'find_next_bit' 'do_exit' 'xas_find_marked' 'do_nanosleep' 'timer_clear_idle' 'ext4_mb_good_group' 'find_get_pages_range_tag' 'ext4_free_inodes_count' 'tick_do_update_jiffies64' 'do_syslog' '__mark_inode_dirty' 'wbt_issue' 'blk_mq_get_request' 'vm_area_dup' '__ext4_new_inode' 'copy_process' '__snd_rawmidi_transmit_ack' 'ext4_sync_file' 'mod_timer' 'taskstats_exit' 'dd_has_work' 'mmap_region' 'common_perm_cond' 'xas_clear_mark' 'page_counter_try_charge' 'ktime_get_real_seconds' [ 224.766787][ T7780] ================================================================== [ 224.774962][ T7780] BUG: KCSAN: data-race in poll_schedule_timeout.constprop.0 / watchdog [ 224.783257][ T7780] [ 224.785567][ T7780] read to 0xffff888126da4090 of 8 bytes by task 857 on cpu 0: [ 224.793017][ T7780] watchdog+0x2b1/0x960 [ 224.797175][ T7780] kthread+0x1d4/0x200 [ 224.801245][ T7780] ret_from_fork+0x1f/0x30 [ 224.805645][ T7780] [ 224.807975][ T7780] write to 0xffff888126da4090 of 8 bytes by task 7780 on cpu 1: [ 224.815621][ T7780] poll_schedule_timeout.constprop.0+0x8f/0xc0 [ 224.821788][ T7780] do_select+0xd7f/0x1020 [ 224.826108][ T7780] core_sys_select+0x312/0x650 [ 224.830878][ T7780] do_pselect.constprop.0+0x11d/0x160 [ 224.836585][ T7780] __x64_sys_pselect6+0x12e/0x170 [ 224.841600][ T7780] do_syscall_64+0xcc/0x3a0 [ 224.846095][ T7780] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 224.852073][ T7780] [ 224.854416][ T7780] Reported by Kernel Concurrency Sanitizer on: [ 224.860565][ T7780] CPU: 1 PID: 7780 Comm: syz-fuzzer Not tainted 5.5.0-rc1-syzkaller #0 [ 224.868786][ T7780] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 224.878837][ T7780] ================================================================== [ 224.886888][ T7780] Kernel panic - not syncing: panic_on_warn set ... [ 224.893493][ T7780] CPU: 1 PID: 7780 Comm: syz-fuzzer Not tainted 5.5.0-rc1-syzkaller #0 [ 224.901713][ T7780] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 224.916020][ T7780] Call Trace: [ 224.919308][ T7780] dump_stack+0x11d/0x181 [ 224.923632][ T7780] panic+0x210/0x640 [ 224.927539][ T7780] ? vprintk_func+0x8d/0x140 [ 224.932129][ T7780] kcsan_report.cold+0xc/0xd [ 224.936715][ T7780] kcsan_setup_watchpoint+0x3fe/0x460 [ 224.942089][ T7780] __tsan_unaligned_write8+0xc7/0x110 [ 224.947472][ T7780] poll_schedule_timeout.constprop.0+0x8f/0xc0 [ 224.953622][ T7780] do_select+0xd7f/0x1020 [ 224.957951][ T7780] ? __const_udelay+0x36/0x40 [ 224.962618][ T7780] ? __udelay+0x10/0x20 [ 224.966770][ T7780] ? __rcu_read_unlock+0x66/0x3d0 [ 224.971804][ T7780] ? __rcu_read_unlock+0x66/0x3d0 [ 224.976828][ T7780] ? update_load_avg+0x7b/0x5d0 [ 224.981673][ T7780] ? __sanitizer_cov_trace_switch+0x49/0x80 [ 224.987557][ T7780] ? __read_once_size+0x41/0xe0 [ 224.992413][ T7780] ? __sanitizer_cov_trace_cmp8+0x18/0x20 [ 224.998138][ T7780] ? gup_pgd_range+0x5cb/0x1990 [ 225.002989][ T7780] ? __read_once_size.constprop.0+0x12/0x20 [ 225.008871][ T7780] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 225.015100][ T7780] ? should_fail+0xd4/0x45d [ 225.019601][ T7780] ? __sanitizer_cov_trace_switch+0x49/0x80 [ 225.025483][ T7780] ? __read_once_size+0x41/0xe0 [ 225.030325][ T7780] ? __sanitizer_cov_trace_const_cmp1+0x1a/0x20 [ 225.036551][ T7780] ? get_futex_key+0x55e/0xa10 [ 225.041304][ T7780] ? __rcu_read_unlock+0x66/0x3d0 [ 225.046319][ T7780] ? __sanitizer_cov_trace_switch+0x49/0x80 [ 225.052205][ T7780] core_sys_select+0x312/0x650 [ 225.056966][ T7780] ? __sanitizer_cov_trace_switch+0x49/0x80 [ 225.062848][ T7780] ? __sanitizer_cov_trace_cmp8+0x18/0x20 [ 225.068564][ T7780] ? _copy_to_user+0x84/0xb0 [ 225.073143][ T7780] ? __sanitizer_cov_trace_switch+0x49/0x80 [ 225.079021][ T7780] ? __read_once_size+0x5a/0xe0 [ 225.083862][ T7780] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 225.090091][ T7780] ? ktime_get_ts64+0x286/0x2c0 [ 225.094932][ T7780] ? __sanitizer_cov_trace_cmp8+0x18/0x20 [ 225.100637][ T7780] ? timespec64_add_safe+0xae/0xd0 [ 225.105749][ T7780] do_pselect.constprop.0+0x11d/0x160 [ 225.111130][ T7780] __x64_sys_pselect6+0x12e/0x170 [ 225.116152][ T7780] ? switch_fpu_return+0x11e/0x250 [ 225.121266][ T7780] do_syscall_64+0xcc/0x3a0 [ 225.125772][ T7780] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 225.131653][ T7780] RIP: 0033:0x45ac23 [ 225.135544][ T7780] Code: 48 89 44 24 08 bf 00 00 00 00 be 00 00 00 00 ba 00 00 00 00 41 ba 00 00 00 00 49 89 e0 41 b9 00 00 00 00 b8 0e 01 00 00 0f 05 <48> 8b 6c 24 10 48 83 c4 18 c3 cc cc cc b8 ba 00 00 00 0f 05 89 44 [ 225.155149][ T7780] RSP: 002b:000000c42004ff08 EFLAGS: 00000202 ORIG_RAX: 000000000000010e [ 225.163551][ T7780] RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 000000000045ac23 [ 225.171510][ T7780] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 [ 225.179476][ T7780] RBP: 000000c42004ff18 R08: 000000c42004ff08 R09: 0000000000000000 [ 225.187433][ T7780] R10: 0000000000000000 R11: 0000000000000202 R12: 000000000042f0a0 [ 225.195392][ T7780] R13: 00000000000000f1 R14: 0000000000000011 R15: 0000000000000000 [ 225.204712][ T7780] Kernel Offset: disabled [ 225.209124][ T7780] Rebooting in 86400 seconds..