[....] 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.
[   53.590801][   T26] kauditd_printk_skb: 7 callbacks suppressed
[   53.590816][   T26] audit: type=1800 audit(1574289344.726:29): pid=7446 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="rc.local" dev="sda1" ino=2465 res=0
[   53.624112][   T26] audit: type=1800 audit(1574289344.726:30): pid=7446 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="rmnologin" dev="sda1" ino=2456 res=0

Debian GNU/Linux 7 syzkaller ttyS0

Warning: Permanently added '10.128.0.135' (ECDSA) to the list of known hosts.
2019/11/20 22:35:54 fuzzer started
2019/11/20 22:35:56 dialing manager at 10.128.0.105:37585
2019/11/20 22:35:57 syscalls: 2566
2019/11/20 22:35:57 code coverage: enabled
2019/11/20 22:35:57 comparison tracing: enabled
2019/11/20 22:35:57 extra coverage: extra coverage is not supported by the kernel
2019/11/20 22:35:57 setuid sandbox: enabled
2019/11/20 22:35:57 namespace sandbox: enabled
2019/11/20 22:35:57 Android sandbox: /sys/fs/selinux/policy does not exist
2019/11/20 22:35:57 fault injection: enabled
2019/11/20 22:35:57 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled
2019/11/20 22:35:57 net packet injection: enabled
2019/11/20 22:35:57 net device setup: enabled
2019/11/20 22:35:57 concurrency sanitizer: enabled
2019/11/20 22:35:57 devlink PCI setup: PCI device 0000:00:10.0 is not available
2019/11/20 22:36:01 adding functions to KCSAN blacklist: 'ext4_nonda_switch' 'blk_mq_sched_dispatch_requests' 'pid_update_inode' 'xas_clear_mark' 'ext4_mb_find_by_goal' 'pipe_poll' 'atime_needs_update' 'blk_mq_dispatch_rq_list' 'ext4_free_inode' 'tomoyo_supervisor' 'run_timer_softirq' 'ep_poll' '__ext4_new_inode' 'tcp_add_backlog' 'sctp_assoc_migrate' 'taskstats_exit' '__hrtimer_run_queues' 'futex_wait_queue_me' 'find_get_pages_range_tag' 'find_next_bit' 'tick_do_update_jiffies64' 'ext4_has_free_clusters' 'generic_write_end' 'wbt_done' 'generic_fillattr' 'do_nanosleep' 'poll_schedule_timeout' 'rcu_gp_fqs_check_wake' 
syzkaller login: [   70.672404][ T7608] KCSAN: could not find function: 'poll_schedule_timeout'
[   77.917088][ T7595] ==================================================================
[   77.925596][ T7595] BUG: KCSAN: data-race in mod_timer / timer_clear_idle
[   77.933246][ T7595] 
[   77.935737][ T7595] write to 0xffff88812bf1b6e4 of 1 bytes by task 0 on cpu 1:
[   77.943113][ T7595]  timer_clear_idle+0x42/0x50
[   77.947909][ T7595]  __tick_nohz_idle_restart_tick+0x36/0x1b0
[   77.953792][ T7595]  tick_nohz_idle_exit+0x1af/0x1e0
[   77.958933][ T7595]  do_idle+0xb1/0x280
[   77.962946][ T7595]  cpu_startup_entry+0x1b/0x20
[   77.967905][ T7595]  start_secondary+0x168/0x1b0
[   77.972857][ T7595]  secondary_startup_64+0xa4/0xb0
[   77.977989][ T7595] 
[   77.980326][ T7595] read to 0xffff88812bf1b6e4 of 1 bytes by task 7595 on cpu 0:
[   77.988413][ T7595]  mod_timer+0x50d/0x7a0
[   77.992653][ T7595]  sk_reset_timer+0x2d/0x70
[   77.997315][ T7595]  tcp_rearm_rto+0x1e7/0x2a0
[   78.002011][ T7595]  tcp_event_new_data_sent+0x218/0x220
[   78.007586][ T7595]  tcp_write_xmit+0xa77/0x3120
[   78.012372][ T7595]  __tcp_push_pending_frames+0x7b/0x1d0
[   78.018295][ T7595]  tcp_push+0x1e9/0x3d0
[   78.022531][ T7595]  tcp_sendmsg_locked+0x1d2b/0x1fb0
[   78.027724][ T7595]  tcp_sendmsg+0x39/0x60
[   78.032129][ T7595]  inet_sendmsg+0x6d/0x90
[   78.036449][ T7595]  sock_sendmsg+0x9f/0xc0
[   78.040809][ T7595]  sock_write_iter+0x16b/0x210
[   78.045575][ T7595]  new_sync_write+0x388/0x4a0
[   78.050480][ T7595]  __vfs_write+0xb1/0xc0
[   78.055865][ T7595]  vfs_write+0x18a/0x390
[   78.060887][ T7595]  ksys_write+0xd5/0x1b0
[   78.065288][ T7595]  __x64_sys_write+0x4c/0x60
[   78.070035][ T7595]  do_syscall_64+0xcc/0x370
[   78.074545][ T7595]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
[   78.080420][ T7595] 
[   78.082737][ T7595] Reported by Kernel Concurrency Sanitizer on:
[   78.088930][ T7595] CPU: 0 PID: 7595 Comm: syz-fuzzer Not tainted 5.4.0-rc7+ #0
[   78.096496][ T7595] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
[   78.106622][ T7595] ==================================================================
[   78.114670][ T7595] Kernel panic - not syncing: panic_on_warn set ...
[   78.121251][ T7595] CPU: 0 PID: 7595 Comm: syz-fuzzer Not tainted 5.4.0-rc7+ #0
[   78.129103][ T7595] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
[   78.139196][ T7595] Call Trace:
[   78.142680][ T7595]  dump_stack+0x11d/0x181
[   78.147011][ T7595]  panic+0x210/0x640
[   78.151116][ T7595]  ? vprintk_func+0x8d/0x140
[   78.155791][ T7595]  kcsan_report.cold+0xc/0xd
[   78.160448][ T7595]  kcsan_setup_watchpoint+0x3fe/0x460
[   78.166037][ T7595]  __tsan_read1+0xc2/0x100
[   78.170458][ T7595]  mod_timer+0x50d/0x7a0
[   78.175104][ T7595]  ? tcp_update_skb_after_send+0x1a6/0x260
[   78.181215][ T7595]  ? __sanitizer_cov_trace_const_cmp4+0x16/0x20
[   78.188237][ T7595]  sk_reset_timer+0x2d/0x70
[   78.192736][ T7595]  tcp_rearm_rto+0x1e7/0x2a0
[   78.197323][ T7595]  tcp_event_new_data_sent+0x218/0x220
[   78.202860][ T7595]  tcp_write_xmit+0xa77/0x3120
[   78.207622][ T7595]  ? kmem_cache_alloc_node_trace+0x273/0x670
[   78.213687][ T7595]  __tcp_push_pending_frames+0x7b/0x1d0
[   78.220141][ T7595]  tcp_push+0x1e9/0x3d0
[   78.224287][ T7595]  tcp_sendmsg_locked+0x1d2b/0x1fb0
[   78.229488][ T7595]  tcp_sendmsg+0x39/0x60
[   78.233752][ T7595]  inet_sendmsg+0x6d/0x90
[   78.238301][ T7595]  ? inet_send_prepare+0x200/0x200
[   78.243439][ T7595]  sock_sendmsg+0x9f/0xc0
[   78.247761][ T7595]  sock_write_iter+0x16b/0x210
[   78.252554][ T7595]  new_sync_write+0x388/0x4a0
[   78.257233][ T7595]  __vfs_write+0xb1/0xc0
[   78.261551][ T7595]  vfs_write+0x18a/0x390
[   78.265960][ T7595]  ksys_write+0xd5/0x1b0
[   78.270192][ T7595]  __x64_sys_write+0x4c/0x60
[   78.274782][ T7595]  do_syscall_64+0xcc/0x370
[   78.279284][ T7595]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
[   78.285164][ T7595] RIP: 0033:0x47c530
[   78.289055][ T7595] Code: 8b 7c 24 10 48 8b 74 24 18 48 8b 54 24 20 49 c7 c2 00 00 00 00 49 c7 c0 00 00 00 00 49 c7 c1 00 00 00 00 48 8b 44 24 08 0f 05 <48> 3d 01 f0 ff ff 76 20 48 c7 44 24 28 ff ff ff ff 48 c7 44 24 30
[   78.308993][ T7595] RSP: 002b:000000c4208694f8 EFLAGS: 00000216 ORIG_RAX: 0000000000000001
[   78.317620][ T7595] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000047c530
[   78.325672][ T7595] RDX: 0000000000000007 RSI: 000000c42016a020 RDI: 0000000000000003
[   78.333633][ T7595] RBP: 000000c420869550 R08: 0000000000000000 R09: 0000000000000000
[   78.341859][ T7595] R10: 0000000000000000 R11: 0000000000000216 R12: 000000c4200c5b00
[   78.349827][ T7595] R13: 000000000000000f R14: 0000000000c1ec00 R15: 0000000000000741
[   79.497903][ T7595] Shutting down cpus with NMI
[   79.503986][ T7595] Kernel Offset: disabled
[   79.508662][ T7595] Rebooting in 86400 seconds..