[ 43.012425][ T26] audit: type=1800 audit(1572322688.652:24): pid=7146 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="sudo" dev="sda1" ino=2487 res=0 [....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 43.329898][ T26] audit: type=1800 audit(1572322689.062:25): pid=7146 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 43.349931][ T26] audit: type=1800 audit(1572322689.072:26): pid=7146 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. [....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 Warning: Permanently added '10.128.0.103' (ECDSA) to the list of known hosts. 2019/10/29 04:18:19 fuzzer started 2019/10/29 04:18:20 dialing manager at 10.128.0.105:40771 2019/10/29 04:18:21 syscalls: 2540 2019/10/29 04:18:21 code coverage: enabled 2019/10/29 04:18:21 comparison tracing: enabled 2019/10/29 04:18:21 extra coverage: extra coverage is not supported by the kernel 2019/10/29 04:18:21 setuid sandbox: enabled 2019/10/29 04:18:21 namespace sandbox: enabled 2019/10/29 04:18:21 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/29 04:18:21 fault injection: enabled 2019/10/29 04:18:21 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/29 04:18:21 net packet injection: enabled 2019/10/29 04:18:21 net device setup: enabled 2019/10/29 04:18:21 concurrency sanitizer: enabled 2019/10/29 04:18:25 adding functions to KCSAN blacklist: '__hrtimer_run_queues' 'tomoyo_supervisor' 'pid_update_inode' 'alloc_pid' 'generic_permission' 'do_nanosleep' 'tcp_add_backlog' 'page_counter_try_charge' 'ep_poll' 'tcp_poll' 'tick_nohz_idle_stop_tick' 'do_exit' '__nf_conntrack_find_get' 'task_dump_owner' '__nf_ct_refresh_acct' 'queue_access_lock' 'ktime_get_real_seconds' 'find_next_bit' syzkaller login: [ 65.883052][ T7311] ================================================================== [ 65.891205][ T7311] BUG: KCSAN: data-race in mod_timer / timer_clear_idle [ 65.898127][ T7311] [ 65.900455][ T7311] write to 0xffff88812bf1b6e4 of 1 bytes by task 0 on cpu 1: [ 65.907813][ T7311] timer_clear_idle+0x42/0x50 [ 65.912476][ T7311] __tick_nohz_idle_restart_tick+0x36/0x1b0 [ 65.918368][ T7311] tick_nohz_idle_exit+0x1af/0x1e0 [ 65.923464][ T7311] do_idle+0xb1/0x280 [ 65.927431][ T7311] cpu_startup_entry+0x1b/0x20 [ 65.932192][ T7311] start_secondary+0x208/0x260 [ 65.936942][ T7311] secondary_startup_64+0xa4/0xb0 [ 65.941939][ T7311] [ 65.944265][ T7311] read to 0xffff88812bf1b6e4 of 1 bytes by task 7311 on cpu 0: [ 65.951794][ T7311] mod_timer+0x50d/0x7a0 [ 65.956151][ T7311] sk_reset_timer+0x2d/0x70 [ 65.960698][ T7311] tcp_rearm_rto.part.0+0x190/0x240 [ 65.965888][ T7311] tcp_rearm_rto+0x4f/0x60 [ 65.970380][ T7311] tcp_event_new_data_sent+0x1bb/0x1c0 [ 65.975834][ T7311] tcp_write_xmit+0xa16/0x3080 [ 65.980583][ T7311] __tcp_push_pending_frames+0x7b/0x1d0 [ 65.986114][ T7311] tcp_push+0x1e9/0x3d0 [ 65.990271][ T7311] tcp_sendmsg_locked+0x1d1e/0x1f30 [ 65.995455][ T7311] tcp_sendmsg+0x39/0x60 [ 65.999679][ T7311] inet_sendmsg+0x6d/0x90 [ 66.003997][ T7311] sock_sendmsg+0x9f/0xc0 [ 66.008313][ T7311] sock_write_iter+0x16b/0x210 [ 66.013060][ T7311] [ 66.015372][ T7311] Reported by Kernel Concurrency Sanitizer on: [ 66.021525][ T7311] CPU: 0 PID: 7311 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 66.028966][ T7311] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 66.039023][ T7311] ================================================================== [ 66.047983][ T7311] Kernel panic - not syncing: panic_on_warn set ... [ 66.054919][ T7311] CPU: 0 PID: 7311 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 66.062624][ T7311] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 66.072778][ T7311] Call Trace: [ 66.076073][ T7311] dump_stack+0xf5/0x159 [ 66.080305][ T7311] panic+0x210/0x640 [ 66.084200][ T7311] ? tcp_sendmsg_locked+0x1d1e/0x1f30 [ 66.089591][ T7311] ? vprintk_func+0x8d/0x140 [ 66.094202][ T7311] kcsan_report.cold+0xc/0x10 [ 66.098889][ T7311] __kcsan_setup_watchpoint+0x32e/0x4a0 [ 66.104428][ T7311] __tsan_read1+0x2c/0x30 [ 66.108757][ T7311] mod_timer+0x50d/0x7a0 [ 66.112989][ T7311] ? __kcsan_setup_watchpoint+0x6b/0x4a0 [ 66.118615][ T7311] ? __kcsan_setup_watchpoint+0x6b/0x4a0 [ 66.124239][ T7311] sk_reset_timer+0x2d/0x70 [ 66.128730][ T7311] tcp_rearm_rto.part.0+0x190/0x240 [ 66.133913][ T7311] tcp_rearm_rto+0x4f/0x60 [ 66.138322][ T7311] tcp_event_new_data_sent+0x1bb/0x1c0 [ 66.143769][ T7311] tcp_write_xmit+0xa16/0x3080 [ 66.148522][ T7311] ? kmem_cache_alloc_node_trace+0x273/0x670 [ 66.154526][ T7311] __tcp_push_pending_frames+0x7b/0x1d0 [ 66.160071][ T7311] tcp_push+0x1e9/0x3d0 [ 66.164224][ T7311] tcp_sendmsg_locked+0x1d1e/0x1f30 [ 66.169431][ T7311] tcp_sendmsg+0x39/0x60 [ 66.173679][ T7311] inet_sendmsg+0x6d/0x90 [ 66.178003][ T7311] ? inet_send_prepare+0x200/0x200 [ 66.183372][ T7311] sock_sendmsg+0x9f/0xc0 [ 66.187881][ T7311] sock_write_iter+0x16b/0x210 [ 66.192655][ T7311] new_sync_write+0x388/0x4a0 [ 66.197356][ T7311] __vfs_write+0xb1/0xc0 [ 66.201596][ T7311] vfs_write+0x18a/0x390 [ 66.205828][ T7311] ksys_write+0xd5/0x1b0 [ 66.210059][ T7311] __x64_sys_write+0x4c/0x60 [ 66.214640][ T7311] do_syscall_64+0xcc/0x370 [ 66.220048][ T7311] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 66.226188][ T7311] RIP: 0033:0x47c530 [ 66.230226][ T7311] 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 [ 66.250219][ T7311] RSP: 002b:000000c4208dd4f8 EFLAGS: 00000216 ORIG_RAX: 0000000000000001 [ 66.259583][ T7311] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000047c530 [ 66.267557][ T7311] RDX: 0000000000000007 RSI: 000000c420098020 RDI: 0000000000000003 [ 66.275807][ T7311] RBP: 000000c4208dd550 R08: 0000000000000000 R09: 0000000000000000 [ 66.283863][ T7311] R10: 0000000000000000 R11: 0000000000000216 R12: 000000c4200b5b00 [ 66.291819][ T7311] R13: 0000000000000007 R14: 0000000000c1d600 R15: 00000000000003e0 [ 67.431876][ T7311] Shutting down cpus with NMI [ 67.438012][ T7311] Kernel Offset: disabled [ 67.442473][ T7311] Rebooting in 86400 seconds..