[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 38.040819][ T25] audit: type=1800 audit(1570445807.193:25): pid=7022 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 38.073719][ T25] audit: type=1800 audit(1570445807.193:26): pid=7022 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 38.103342][ T25] audit: type=1800 audit(1570445807.203:27): pid=7022 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 '10.128.1.6' (ECDSA) to the list of known hosts. 2019/10/07 10:56:54 fuzzer started 2019/10/07 10:56:54 dialing manager at 10.128.0.105:39369 2019/10/07 10:56:54 syscalls: 2523 2019/10/07 10:56:54 code coverage: enabled 2019/10/07 10:56:54 comparison tracing: enabled 2019/10/07 10:56:54 extra coverage: extra coverage is not supported by the kernel 2019/10/07 10:56:54 setuid sandbox: enabled 2019/10/07 10:56:54 namespace sandbox: enabled 2019/10/07 10:56:54 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/07 10:56:54 fault injection: enabled 2019/10/07 10:56:54 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/07 10:56:54 net packet injection: enabled 2019/10/07 10:56:54 net device setup: enabled 2019/10/07 10:56:54 concurrency sanitizer: enabled syzkaller login: [ 45.766173][ T7167] ================================================================== [ 45.774598][ T7167] BUG: KCSAN: data-race in tcp_ack / tcp_poll [ 45.786065][ T7167] [ 45.788427][ T7167] write to 0xffff88812121c188 of 4 bytes by interrupt on cpu 0: [ 45.796130][ T7167] tcp_ack+0xf2c/0x3160 [ 45.800269][ T7167] tcp_rcv_established+0x37e/0xf50 [ 45.805365][ T7167] tcp_v4_do_rcv+0x381/0x4e0 [ 45.810138][ T7167] tcp_v4_rcv+0x1a03/0x1bf0 [ 45.814655][ T7167] ip_protocol_deliver_rcu+0x51/0x470 [ 45.820005][ T7167] ip_local_deliver_finish+0x110/0x140 [ 45.825440][ T7167] ip_local_deliver+0x133/0x210 [ 45.830266][ T7167] ip_rcv_finish+0x121/0x160 [ 45.835273][ T7167] ip_rcv+0x18f/0x1a0 [ 45.839235][ T7167] __netif_receive_skb_one_core+0xa7/0xe0 [ 45.844931][ T7167] __netif_receive_skb+0x37/0xf0 [ 45.849841][ T7167] netif_receive_skb_internal+0x59/0x190 [ 45.855449][ T7167] napi_gro_receive+0x28f/0x330 [ 45.860274][ T7167] receive_buf+0x284/0x30b0 [ 45.864748][ T7167] [ 45.867062][ T7167] read to 0xffff88812121c188 of 4 bytes by task 7167 on cpu 1: [ 45.874580][ T7167] tcp_poll+0x422/0x6b0 [ 45.878720][ T7167] sock_poll+0xed/0x250 [ 45.882880][ T7167] do_select+0x7d0/0x1020 [ 45.887194][ T7167] core_sys_select+0x38b/0x520 [ 45.891932][ T7167] kern_select+0x106/0x170 [ 45.896413][ T7167] __x64_sys_select+0x70/0x90 [ 45.902211][ T7167] do_syscall_64+0xcf/0x2f0 [ 45.906706][ T7167] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 45.914863][ T7167] [ 45.917207][ T7167] Reported by Kernel Concurrency Sanitizer on: [ 45.923343][ T7167] CPU: 1 PID: 7167 Comm: sshd Not tainted 5.3.0+ #0 [ 45.929904][ T7167] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 45.939947][ T7167] ================================================================== [ 45.947983][ T7167] Kernel panic - not syncing: panic_on_warn set ... [ 45.954548][ T7167] CPU: 1 PID: 7167 Comm: sshd Not tainted 5.3.0+ #0 [ 45.961119][ T7167] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 45.971150][ T7167] Call Trace: [ 45.974421][ T7167] dump_stack+0xf5/0x159 [ 45.978659][ T7167] panic+0x209/0x639 [ 45.982535][ T7167] ? vprintk_func+0x8d/0x140 [ 45.987207][ T7167] kcsan_report.cold+0x57/0xeb [ 45.991963][ T7167] __kcsan_setup_watchpoint+0x342/0x500 [ 45.997492][ T7167] __tsan_read4+0x2c/0x30 [ 46.001817][ T7167] tcp_poll+0x422/0x6b0 [ 46.005955][ T7167] ? tcp_alloc_md5sig_pool+0x320/0x320 [ 46.011611][ T7167] sock_poll+0xed/0x250 [ 46.015980][ T7167] ? sock_read_iter+0x1e0/0x1e0 [ 46.020835][ T7167] do_select+0x7d0/0x1020 [ 46.025158][ T7167] ? poll_initwait+0xa0/0xa0 [ 46.029738][ T7167] ? set_fd_set.part.0+0x60/0x60 [ 46.034668][ T7167] ? tcp_push+0x1f3/0x3d0 [ 46.038979][ T7167] ? sock_zerocopy_put+0x78/0x90 [ 46.043897][ T7167] ? tcp_sendmsg_locked+0xc0a/0x1ef0 [ 46.049253][ T7167] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 46.055477][ T7167] ? __this_cpu_preempt_check+0x4a/0x170 [ 46.061091][ T7167] ? __local_bh_enable_ip+0x32/0x80 [ 46.066272][ T7167] ? _raw_spin_unlock_bh+0x44/0x50 [ 46.071365][ T7167] ? __tsan_read8+0x2c/0x30 [ 46.075850][ T7167] ? check_stack_object+0xda/0x110 [ 46.080940][ T7167] ? __tsan_read8+0x2c/0x30 [ 46.085431][ T7167] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 46.091666][ T7167] core_sys_select+0x38b/0x520 [ 46.096456][ T7167] ? __tsan_read8+0x2c/0x30 [ 46.100989][ T7167] ? __sanitizer_cov_trace_switch+0x49/0x80 [ 46.106897][ T7167] ? __tsan_write8+0x32/0x40 [ 46.111537][ T7167] ? ktime_get_ts64+0x286/0x2b0 [ 46.116429][ T7167] ? __sanitizer_cov_trace_cmp8+0x18/0x20 [ 46.122248][ T7167] ? timespec64_add_safe+0xae/0xd0 [ 46.127845][ T7167] kern_select+0x106/0x170 [ 46.132497][ T7167] __x64_sys_select+0x70/0x90 [ 46.138507][ T7167] do_syscall_64+0xcf/0x2f0 [ 46.143187][ T7167] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 46.149111][ T7167] RIP: 0033:0x7ff7abdb7dd3 [ 46.153540][ T7167] Code: 48 29 c2 64 89 11 48 83 c8 ff eb ea 90 90 90 90 90 90 90 90 90 90 90 83 3d 25 48 2b 00 00 75 13 49 89 ca b8 17 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 34 c3 48 83 ec 08 e8 ab 2f 01 00 48 89 04 24 [ 46.173156][ T7167] RSP: 002b:00007ffe8160be18 EFLAGS: 00000246 ORIG_RAX: 0000000000000017 [ 46.181566][ T7167] RAX: ffffffffffffffda RBX: 00007ffe8160bea0 RCX: 00007ff7abdb7dd3 [ 46.189582][ T7167] RDX: 0000555b86a06b00 RSI: 0000555b86a06b20 RDI: 000000000000000c [ 46.200600][ T7167] RBP: 0000555b85d7b8dc R08: 00007ffe8160be40 R09: 0101010101010101 [ 46.208672][ T7167] R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffe8160bea8 [ 46.216687][ T7167] R13: 0000000000000000 R14: 00007ffe8160be98 R15: 00007ffe8160be9c [ 46.225952][ T7167] Kernel Offset: disabled [ 46.230330][ T7167] Rebooting in 86400 seconds..