[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 35.663643][ T25] audit: type=1800 audit(1571323549.874:25): pid=7231 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 35.709779][ T25] audit: type=1800 audit(1571323549.874:26): pid=7231 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [ 36.305657][ T7299] sshd (7299) 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 '10.128.0.12' (ECDSA) to the list of known hosts. 2019/10/17 14:45:58 fuzzer started 2019/10/17 14:46:00 dialing manager at 10.128.0.105:43535 2019/10/17 14:46:00 syscalls: 2524 2019/10/17 14:46:00 code coverage: enabled 2019/10/17 14:46:00 comparison tracing: enabled 2019/10/17 14:46:00 extra coverage: extra coverage is not supported by the kernel 2019/10/17 14:46:00 setuid sandbox: enabled 2019/10/17 14:46:00 namespace sandbox: enabled 2019/10/17 14:46:00 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/17 14:46:00 fault injection: enabled 2019/10/17 14:46:00 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/17 14:46:00 net packet injection: enabled 2019/10/17 14:46:00 net device setup: enabled 2019/10/17 14:46:00 concurrency sanitizer: enabled syzkaller login: [ 47.331580][ T7382] ================================================================== [ 47.341215][ T7382] BUG: KCSAN: data-race in mod_timer / timer_clear_idle [ 47.348127][ T7382] [ 47.350443][ T7382] write to 0xffff88812bf1b6e4 of 1 bytes by task 0 on cpu 1: [ 47.357888][ T7382] timer_clear_idle+0x42/0x50 [ 47.362664][ T7382] __tick_nohz_idle_restart_tick+0x36/0x1b0 [ 47.368714][ T7382] tick_nohz_idle_exit+0x1af/0x1e0 [ 47.374763][ T7382] do_idle+0xb1/0x280 [ 47.378732][ T7382] cpu_startup_entry+0x1b/0x20 [ 47.383482][ T7382] start_secondary+0x208/0x260 [ 47.388232][ T7382] secondary_startup_64+0xa4/0xb0 [ 47.393249][ T7382] [ 47.395567][ T7382] read to 0xffff88812bf1b6e4 of 1 bytes by task 7382 on cpu 0: [ 47.403095][ T7382] mod_timer+0x50d/0x7a0 [ 47.407321][ T7382] sk_reset_timer+0x2d/0x70 [ 47.411813][ T7382] tcp_rearm_rto.part.0+0x190/0x240 [ 47.416993][ T7382] tcp_rearm_rto+0x4f/0x60 [ 47.421404][ T7382] tcp_event_new_data_sent+0x1bb/0x1c0 [ 47.426855][ T7382] tcp_write_xmit+0xa16/0x3080 [ 47.431607][ T7382] __tcp_push_pending_frames+0x7b/0x1d0 [ 47.437310][ T7382] tcp_push+0x1e9/0x3d0 [ 47.441712][ T7382] tcp_sendmsg_locked+0x1d1e/0x1f30 [ 47.447069][ T7382] tcp_sendmsg+0x39/0x60 [ 47.451825][ T7382] inet_sendmsg+0x6d/0x90 [ 47.456137][ T7382] sock_sendmsg+0x9f/0xc0 [ 47.460468][ T7382] sock_write_iter+0x16b/0x210 [ 47.465227][ T7382] [ 47.467625][ T7382] Reported by Kernel Concurrency Sanitizer on: [ 47.475262][ T7382] CPU: 0 PID: 7382 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 47.482709][ T7382] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 47.492850][ T7382] ================================================================== [ 47.500895][ T7382] Kernel panic - not syncing: panic_on_warn set ... [ 47.507467][ T7382] CPU: 0 PID: 7382 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 47.515093][ T7382] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 47.525131][ T7382] Call Trace: [ 47.528429][ T7382] dump_stack+0xf5/0x159 [ 47.532688][ T7382] panic+0x210/0x640 [ 47.536578][ T7382] ? tcp_sendmsg_locked+0x1d1e/0x1f30 [ 47.546203][ T7382] ? vprintk_func+0x8d/0x140 [ 47.550882][ T7382] kcsan_report.cold+0xc/0x10 [ 47.555546][ T7382] __kcsan_setup_watchpoint+0x32e/0x4a0 [ 47.561085][ T7382] __tsan_read1+0x2c/0x30 [ 47.565415][ T7382] mod_timer+0x50d/0x7a0 [ 47.569654][ T7382] ? __kcsan_setup_watchpoint+0x6b/0x4a0 [ 47.575271][ T7382] ? __kcsan_setup_watchpoint+0x6b/0x4a0 [ 47.580902][ T7382] sk_reset_timer+0x2d/0x70 [ 47.585390][ T7382] tcp_rearm_rto.part.0+0x190/0x240 [ 47.590585][ T7382] tcp_rearm_rto+0x4f/0x60 [ 47.594987][ T7382] tcp_event_new_data_sent+0x1bb/0x1c0 [ 47.600433][ T7382] tcp_write_xmit+0xa16/0x3080 [ 47.605194][ T7382] ? kmem_cache_alloc_node_trace+0x273/0x670 [ 47.611181][ T7382] __tcp_push_pending_frames+0x7b/0x1d0 [ 47.616713][ T7382] tcp_push+0x1e9/0x3d0 [ 47.620862][ T7382] tcp_sendmsg_locked+0x1d1e/0x1f30 [ 47.626061][ T7382] tcp_sendmsg+0x39/0x60 [ 47.630293][ T7382] inet_sendmsg+0x6d/0x90 [ 47.634609][ T7382] ? inet_send_prepare+0x200/0x200 [ 47.639717][ T7382] sock_sendmsg+0x9f/0xc0 [ 47.644215][ T7382] sock_write_iter+0x16b/0x210 [ 47.648972][ T7382] new_sync_write+0x388/0x4a0 [ 47.653640][ T7382] __vfs_write+0xb1/0xc0 [ 47.657886][ T7382] vfs_write+0x18a/0x390 [ 47.662117][ T7382] ksys_write+0xd5/0x1b0 [ 47.666347][ T7382] __x64_sys_write+0x4c/0x60 [ 47.670925][ T7382] do_syscall_64+0xcc/0x370 [ 47.675414][ T7382] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 47.681309][ T7382] RIP: 0033:0x47c530 [ 47.685198][ T7382] 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 [ 47.705131][ T7382] RSP: 002b:000000c4203c34f8 EFLAGS: 00000216 ORIG_RAX: 0000000000000001 [ 47.713525][ T7382] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000047c530 [ 47.721485][ T7382] RDX: 0000000000000007 RSI: 000000c4203d0020 RDI: 0000000000000003 [ 47.729440][ T7382] RBP: 000000c4203c3550 R08: 0000000000000000 R09: 0000000000000000 [ 47.737410][ T7382] R10: 0000000000000000 R11: 0000000000000216 R12: 000000c4200c5b00 [ 47.745366][ T7382] R13: 000000000000000f R14: 0000000000c14060 R15: 0000000000000c41 [ 48.881806][ T7382] Shutting down cpus with NMI [ 48.888341][ T7382] Kernel Offset: disabled [ 48.892808][ T7382] Rebooting in 86400 seconds..