[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c.
[ 35.543495][ T25] audit: type=1800 audit(1572003886.018:25): pid=7027 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0
[ 35.570486][ T25] audit: type=1800 audit(1572003886.018:26): pid=7027 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0
[ 35.597291][ T25] audit: type=1800 audit(1572003886.018:27): pid=7027 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="restorecond" dev="sda1" ino=2469 res=0
[....] Starting periodic command scheduler: cron[?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c.
[....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c.
Debian GNU/Linux 7 syzkaller ttyS0
Warning: Permanently added '10.128.0.225' (ECDSA) to the list of known hosts.
2019/10/25 11:44:56 fuzzer started
2019/10/25 11:44:58 dialing manager at 10.128.0.105:33971
2019/10/25 11:44:58 syscalls: 2529
2019/10/25 11:44:58 code coverage: enabled
2019/10/25 11:44:58 comparison tracing: enabled
2019/10/25 11:44:58 extra coverage: extra coverage is not supported by the kernel
2019/10/25 11:44:58 setuid sandbox: enabled
2019/10/25 11:44:58 namespace sandbox: enabled
2019/10/25 11:44:58 Android sandbox: /sys/fs/selinux/policy does not exist
2019/10/25 11:44:58 fault injection: enabled
2019/10/25 11:44:58 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled
2019/10/25 11:44:58 net packet injection: enabled
2019/10/25 11:44:58 net device setup: enabled
2019/10/25 11:44:58 concurrency sanitizer: enabled
2019/10/25 11:45:02 adding functions to KCSAN blacklist: 'echo_char' 'ktime_get_real_seconds' 'pipe_poll' 'mod_timer' 'ext4_setattr' '__nf_ct_refresh_acct' 'tick_do_update_jiffies64' 'generic_permission' 'run_timer_softirq' 'ext4_free_inodes_count' 'tcp_add_backlog' 'ep_poll' 'tcp_poll' 'taskstats_exit' '__hrtimer_run_queues' '__tcp_select_window' 'generic_write_end' 'pid_update_inode' 'find_next_bit' 'tomoyo_supervisor' 'rcu_gp_fqs_check_wake'
syzkaller login: [ 56.962172][ C0] ==================================================================
[ 56.970333][ C0] BUG: KCSAN: data-race in tick_sched_do_timer / tick_sched_do_timer
[ 56.978406][ C0]
[ 56.980720][ C0] read to 0xffffffff85cb2790 of 4 bytes by interrupt on cpu 1:
[ 56.988239][ C0] tick_sched_do_timer+0x33/0xe0
[ 56.993600][ C0] tick_sched_timer+0x43/0xe0
[ 56.998252][ C0] __hrtimer_run_queues+0x288/0x600
[ 57.003425][ C0] hrtimer_interrupt+0x22a/0x480
[ 57.008349][ C0] smp_apic_timer_interrupt+0xdc/0x280
[ 57.013780][ C0] apic_timer_interrupt+0xf/0x20
[ 57.018737][ C0] _raw_spin_unlock_irq+0x4e/0x80
[ 57.023744][ C0] finish_task_switch+0x7b/0x260
[ 57.028656][ C0] __schedule+0x319/0x640
[ 57.032963][ C0] schedule_idle+0x27/0x40
[ 57.037355][ C0] do_idle+0xc9/0x280
[ 57.041317][ C0] cpu_startup_entry+0x1b/0x20
[ 57.046057][ C0] start_secondary+0x208/0x260
[ 57.050796][ C0] secondary_startup_64+0xa4/0xb0
[ 57.055789][ C0]
[ 57.058094][ C0] write to 0xffffffff85cb2790 of 4 bytes by interrupt on cpu 0:
[ 57.065731][ C0] tick_sched_do_timer+0xc0/0xe0
[ 57.070645][ C0] tick_sched_timer+0x43/0xe0
[ 57.075298][ C0] __hrtimer_run_queues+0x288/0x600
[ 57.080468][ C0] hrtimer_interrupt+0x22a/0x480
[ 57.085379][ C0] smp_apic_timer_interrupt+0xdc/0x280
[ 57.090830][ C0] apic_timer_interrupt+0xf/0x20
[ 57.095745][ C0] handle_mm_fault+0x138/0x530
[ 57.100484][ C0] __do_page_fault+0x3fb/0x9e0
[ 57.105221][ C0] do_page_fault+0x54/0x233
[ 57.109696][ C0] page_fault+0x34/0x40
[ 57.113828][ C0]
[ 57.116128][ C0] Reported by Kernel Concurrency Sanitizer on:
[ 57.122259][ C0] CPU: 0 PID: 7179 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0
[ 57.129684][ C0] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
[ 57.139753][ C0] ==================================================================
[ 57.147794][ C0] Kernel panic - not syncing: panic_on_warn set ...
[ 57.154359][ C0] CPU: 0 PID: 7179 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0
[ 57.161793][ C0] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
[ 57.171823][ C0] Call Trace:
[ 57.175083][ C0]
[ 57.177923][ C0] dump_stack+0xf5/0x159
[ 57.182140][ C0] panic+0x210/0x640
[ 57.186010][ C0] ? do_page_fault+0x54/0x233
[ 57.190673][ C0] ? vprintk_func+0x8d/0x140
[ 57.195239][ C0] kcsan_report.cold+0xc/0x10
[ 57.199903][ C0] __kcsan_setup_watchpoint+0x32e/0x4a0
[ 57.205425][ C0] __tsan_write4+0x32/0x40
[ 57.209831][ C0] tick_sched_do_timer+0xc0/0xe0
[ 57.214745][ C0] tick_sched_timer+0x43/0xe0
[ 57.219403][ C0] __hrtimer_run_queues+0x288/0x600
[ 57.224577][ C0] ? tick_sched_do_timer+0xe0/0xe0
[ 57.229674][ C0] hrtimer_interrupt+0x22a/0x480
[ 57.234593][ C0] smp_apic_timer_interrupt+0xdc/0x280
[ 57.240035][ C0] ? smp_reschedule_interrupt+0x71/0x1d0
[ 57.245644][ C0] apic_timer_interrupt+0xf/0x20
[ 57.250551][ C0]
[ 57.253465][ C0] RIP: 0010:handle_mm_fault+0x138/0x530
[ 57.258988][ C0] Code: ff e8 0c 50 0b 00 48 c7 c7 a0 63 a5 85 e8 10 21 f3 ff 48 83 3d a8 bd 45 04 00 0f 84 5e 03 00 00 e8 dd 21 e6 ff 48 89 df 57 9d <0f> 1f 44 00 00 e8 ce 21 e6 ff e8 49 20 db ff e8 c4 21 e6 ff e8 bf
[ 57.278568][ C0] RSP: 0000:ffffc900015d7e28 EFLAGS: 00000293 ORIG_RAX: ffffffffffffff13
[ 57.286954][ C0] RAX: ffff88812a2b4100 RBX: 0000000000000293 RCX: 0000000000000784
[ 57.294900][ C0] RDX: 0000000000000000 RSI: ffffffff815fa603 RDI: 0000000000000293
[ 57.302867][ C0] RBP: ffffc900015d7e80 R08: 0000000000000000 R09: 0000ffff85a563a7
[ 57.310824][ C0] R10: 00000000aaaaaaab R11: ffffffff86045cc8 R12: ffff888122497898
[ 57.318780][ C0] R13: 0000000000000055 R14: ffff8881224978d8 R15: ffff88812b33b000
[ 57.326741][ C0] ? handle_mm_fault+0x133/0x530
[ 57.331660][ C0] __do_page_fault+0x3fb/0x9e0
[ 57.336406][ C0] do_page_fault+0x54/0x233
[ 57.341148][ C0] ? do_syscall_64+0x270/0x370
[ 57.345906][ C0] page_fault+0x34/0x40
[ 57.350047][ C0] RIP: 0033:0x45a2a3
[ 57.353932][ C0] Code: 00 48 81 eb 00 01 00 00 48 81 c7 00 01 00 00 48 81 fb 00 01 00 00 73 82 e9 07 ff ff ff c5 fd ef c0 48 81 fb 00 00 00 02 73 46 fe 7f 07 c5 fe 7f 47 20 c5 fe 7f 47 40 c5 fe 7f 47 60 48 81 eb
[ 57.373532][ C0] RSP: 002b:00007ffef8929c98 EFLAGS: 00010202
[ 57.379570][ C0] RAX: 0000000000000000 RBX: 0000000000001000 RCX: 0000000000002000
[ 57.387515][ C0] RDX: 0000000000000000 RSI: 0000000000000001 RDI: 000000c420601000
[ 57.395463][ C0] RBP: 00007ffef8929ce0 R08: 000000c000000000 R09: 0000000000000300
[ 57.403420][ C0] R10: 00007f5fce7b9228 R11: 7fffffffffffffff R12: 0000000000000000
[ 57.411368][ C0] R13: 0000000000000001 R14: 0000000000000001 R15: 0000000000000001
[ 57.420613][ C0] Kernel Offset: disabled
[ 57.424928][ C0] Rebooting in 86400 seconds..