[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 35.111702][ T25] audit: type=1800 audit(1572728779.236:25): pid=7122 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 35.145955][ T25] audit: type=1800 audit(1572728779.236:26): pid=7122 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 35.169353][ T25] audit: type=1800 audit(1572728779.236:27): pid=7122 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[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 Warning: Permanently added '10.128.0.45' (ECDSA) to the list of known hosts. 2019/11/02 21:06:31 fuzzer started 2019/11/02 21:06:33 dialing manager at 10.128.0.105:46001 2019/11/02 21:06:33 syscalls: 2554 2019/11/02 21:06:33 code coverage: enabled 2019/11/02 21:06:33 comparison tracing: enabled 2019/11/02 21:06:33 extra coverage: extra coverage is not supported by the kernel 2019/11/02 21:06:33 setuid sandbox: enabled 2019/11/02 21:06:33 namespace sandbox: enabled 2019/11/02 21:06:33 Android sandbox: /sys/fs/selinux/policy does not exist 2019/11/02 21:06:33 fault injection: enabled 2019/11/02 21:06:33 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/11/02 21:06:33 net packet injection: enabled 2019/11/02 21:06:33 net device setup: enabled 2019/11/02 21:06:33 concurrency sanitizer: enabled 2019/11/02 21:06:35 adding functions to KCSAN blacklist: '__nf_conntrack_find_get' 'find_next_bit' 'vm_area_dup' 'task_dump_owner' 'tcp_add_backlog' 'pcpu_alloc' '__hrtimer_run_queues' 'rcu_gp_fqs_check_wake' '__tcp_select_window' syzkaller login: [ 52.067350][ T7291] ================================================================== [ 52.075474][ T7291] BUG: KCSAN: data-race in mod_timer / timer_clear_idle [ 52.082381][ T7291] [ 52.084696][ T7291] write to 0xffff88812bf1b6e4 of 1 bytes by task 0 on cpu 1: [ 52.092048][ T7291] timer_clear_idle+0x42/0x50 [ 52.096712][ T7291] __tick_nohz_idle_restart_tick+0x36/0x1b0 [ 52.102605][ T7291] tick_nohz_idle_exit+0x1af/0x1e0 [ 52.107698][ T7291] do_idle+0xb1/0x280 [ 52.111663][ T7291] cpu_startup_entry+0x1b/0x20 [ 52.116410][ T7291] start_secondary+0x208/0x260 [ 52.121159][ T7291] secondary_startup_64+0xa4/0xb0 [ 52.126157][ T7291] [ 52.128474][ T7291] read to 0xffff88812bf1b6e4 of 1 bytes by task 7291 on cpu 0: [ 52.136009][ T7291] mod_timer+0x50d/0x7a0 [ 52.140248][ T7291] sk_reset_timer+0x2d/0x70 [ 52.144742][ T7291] tcp_rearm_rto.part.0+0x190/0x240 [ 52.149935][ T7291] tcp_rearm_rto+0x4f/0x60 [ 52.154341][ T7291] tcp_event_new_data_sent+0x1bb/0x1c0 [ 52.159784][ T7291] tcp_write_xmit+0xa16/0x3080 [ 52.164532][ T7291] __tcp_push_pending_frames+0x7b/0x1d0 [ 52.170058][ T7291] tcp_push+0x1e9/0x3d0 [ 52.174198][ T7291] tcp_sendmsg_locked+0x1d1e/0x1f30 [ 52.179391][ T7291] tcp_sendmsg+0x39/0x60 [ 52.183616][ T7291] inet_sendmsg+0x6d/0x90 [ 52.187928][ T7291] sock_sendmsg+0x9f/0xc0 [ 52.192240][ T7291] sock_write_iter+0x16b/0x210 [ 52.196987][ T7291] [ 52.199293][ T7291] Reported by Kernel Concurrency Sanitizer on: [ 52.205429][ T7291] CPU: 0 PID: 7291 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 52.212860][ T7291] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 52.222901][ T7291] ================================================================== [ 52.230941][ T7291] Kernel panic - not syncing: panic_on_warn set ... [ 52.237511][ T7291] CPU: 0 PID: 7291 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 52.244946][ T7291] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 52.254978][ T7291] Call Trace: [ 52.258260][ T7291] dump_stack+0xf5/0x159 [ 52.262496][ T7291] panic+0x210/0x640 [ 52.266380][ T7291] ? tcp_sendmsg_locked+0x1d1e/0x1f30 [ 52.271747][ T7291] ? vprintk_func+0x8d/0x140 [ 52.276323][ T7291] kcsan_report.cold+0xc/0x10 [ 52.280986][ T7291] __kcsan_setup_watchpoint+0x32e/0x4a0 [ 52.286513][ T7291] __tsan_read1+0x2c/0x30 [ 52.290829][ T7291] mod_timer+0x50d/0x7a0 [ 52.295053][ T7291] ? __kcsan_setup_watchpoint+0x6b/0x4a0 [ 52.300668][ T7291] ? __kcsan_setup_watchpoint+0x6b/0x4a0 [ 52.306301][ T7291] sk_reset_timer+0x2d/0x70 [ 52.310800][ T7291] tcp_rearm_rto.part.0+0x190/0x240 [ 52.315992][ T7291] tcp_rearm_rto+0x4f/0x60 [ 52.320395][ T7291] tcp_event_new_data_sent+0x1bb/0x1c0 [ 52.325850][ T7291] tcp_write_xmit+0xa16/0x3080 [ 52.330602][ T7291] ? kmem_cache_alloc_node_trace+0x273/0x670 [ 52.336577][ T7291] __tcp_push_pending_frames+0x7b/0x1d0 [ 52.342105][ T7291] tcp_push+0x1e9/0x3d0 [ 52.346252][ T7291] tcp_sendmsg_locked+0x1d1e/0x1f30 [ 52.351459][ T7291] tcp_sendmsg+0x39/0x60 [ 52.355687][ T7291] inet_sendmsg+0x6d/0x90 [ 52.360001][ T7291] ? inet_send_prepare+0x200/0x200 [ 52.365100][ T7291] sock_sendmsg+0x9f/0xc0 [ 52.369416][ T7291] sock_write_iter+0x16b/0x210 [ 52.374177][ T7291] new_sync_write+0x388/0x4a0 [ 52.378844][ T7291] __vfs_write+0xb1/0xc0 [ 52.383070][ T7291] vfs_write+0x18a/0x390 [ 52.387298][ T7291] ksys_write+0xd5/0x1b0 [ 52.391530][ T7291] __x64_sys_write+0x4c/0x60 [ 52.396107][ T7291] do_syscall_64+0xcc/0x370 [ 52.400598][ T7291] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 52.406473][ T7291] RIP: 0033:0x47c530 [ 52.410356][ T7291] 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 [ 52.429941][ T7291] RSP: 002b:000000c4204ef4f8 EFLAGS: 00000216 ORIG_RAX: 0000000000000001 [ 52.438336][ T7291] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000047c530 [ 52.446291][ T7291] RDX: 0000000000000007 RSI: 000000c420052200 RDI: 0000000000000003 [ 52.454242][ T7291] RBP: 000000c4204ef550 R08: 0000000000000000 R09: 0000000000000000 [ 52.462203][ T7291] R10: 0000000000000000 R11: 0000000000000216 R12: 000000c4200c3b00 [ 52.472675][ T7291] R13: 000000000000000f R14: 0000000000c1da60 R15: 0000000000000e41 [ 53.607518][ T7291] Shutting down cpus with NMI [ 53.613428][ T7291] Kernel Offset: disabled [ 53.617751][ T7291] Rebooting in 86400 seconds..