[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 36.054772][ T25] audit: type=1800 audit(1571779499.376:25): pid=7136 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 36.097329][ T25] audit: type=1800 audit(1571779499.376:26): pid=7136 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 36.125711][ T25] audit: type=1800 audit(1571779499.376:27): pid=7136 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 '10.128.0.144' (ECDSA) to the list of known hosts. 2019/10/22 21:25:10 fuzzer started 2019/10/22 21:25:12 dialing manager at 10.128.0.105:33369 2019/10/22 21:25:12 syscalls: 2524 2019/10/22 21:25:12 code coverage: enabled 2019/10/22 21:25:12 comparison tracing: enabled 2019/10/22 21:25:12 extra coverage: extra coverage is not supported by the kernel 2019/10/22 21:25:12 setuid sandbox: enabled 2019/10/22 21:25:12 namespace sandbox: enabled 2019/10/22 21:25:12 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/22 21:25:12 fault injection: enabled 2019/10/22 21:25:12 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/22 21:25:12 net packet injection: enabled 2019/10/22 21:25:12 net device setup: enabled 2019/10/22 21:25:12 concurrency sanitizer: enabled syzkaller login: [ 49.704521][ T7304] ================================================================== [ 49.712819][ T7304] BUG: KCSAN: data-race in tcp_poll / tcp_queue_rcv [ 49.719441][ T7304] [ 49.721863][ T7304] write to 0xffff888126fcd778 of 4 bytes by interrupt on cpu 0: [ 49.729670][ T7304] tcp_queue_rcv+0xe9/0x380 [ 49.734451][ T7304] tcp_rcv_established+0xbf1/0xf50 [ 49.739588][ T7304] tcp_v4_do_rcv+0x381/0x4e0 [ 49.744604][ T7304] tcp_v4_rcv+0x19dc/0x1bb0 [ 49.749542][ T7304] ip_protocol_deliver_rcu+0x4d/0x420 [ 49.755132][ T7304] ip_local_deliver_finish+0x110/0x140 [ 49.760989][ T7304] ip_local_deliver+0x133/0x210 [ 49.766177][ T7304] ip_rcv_finish+0x121/0x160 [ 49.770818][ T7304] ip_rcv+0x18f/0x1a0 [ 49.774890][ T7304] __netif_receive_skb_one_core+0xa7/0xe0 [ 49.780828][ T7304] __netif_receive_skb+0x37/0xf0 [ 49.786156][ T7304] netif_receive_skb_internal+0x59/0x190 [ 49.792052][ T7304] napi_gro_receive+0x28f/0x330 [ 49.797172][ T7304] receive_buf+0x284/0x30b0 [ 49.801796][ T7304] [ 49.804119][ T7304] read to 0xffff888126fcd778 of 4 bytes by task 7304 on cpu 1: [ 49.813101][ T7304] tcp_poll+0x204/0x6b0 [ 49.817706][ T7304] sock_poll+0xed/0x250 [ 49.822206][ T7304] ep_item_poll.isra.0+0x90/0x190 [ 49.827236][ T7304] ep_send_events_proc+0x113/0x590 [ 49.832526][ T7304] ep_scan_ready_list.constprop.0+0x189/0x500 [ 49.838790][ T7304] ep_poll+0xe3/0x900 [ 49.842874][ T7304] do_epoll_wait+0x162/0x180 [ 49.847574][ T7304] __x64_sys_epoll_pwait+0xcd/0x180 [ 49.853910][ T7304] do_syscall_64+0xcc/0x370 [ 49.858643][ T7304] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 49.864829][ T7304] [ 49.867341][ T7304] Reported by Kernel Concurrency Sanitizer on: [ 49.874003][ T7304] CPU: 1 PID: 7304 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 49.882071][ T7304] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 49.892420][ T7304] ================================================================== [ 49.900957][ T7304] Kernel panic - not syncing: panic_on_warn set ... [ 49.907877][ T7304] CPU: 1 PID: 7304 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 49.916384][ T7304] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 49.927293][ T7304] Call Trace: [ 49.930700][ T7304] dump_stack+0xf5/0x159 [ 49.934955][ T7304] panic+0x210/0x640 [ 49.940307][ T7304] ? do_syscall_64+0xcc/0x370 [ 49.945561][ T7304] ? vprintk_func+0x8d/0x140 [ 49.950271][ T7304] kcsan_report.cold+0xc/0x10 [ 49.955060][ T7304] __kcsan_setup_watchpoint+0x32e/0x4a0 [ 49.960695][ T7304] __tsan_read4+0x2c/0x30 [ 49.965606][ T7304] tcp_poll+0x204/0x6b0 [ 49.969767][ T7304] ? tcp_alloc_md5sig_pool+0x320/0x320 [ 49.975527][ T7304] sock_poll+0xed/0x250 [ 49.980070][ T7304] ? sock_read_iter+0x1e0/0x1e0 [ 49.985183][ T7304] ep_item_poll.isra.0+0x90/0x190 [ 49.990517][ T7304] ep_send_events_proc+0x113/0x590 [ 49.995631][ T7304] ? __schedule+0x319/0x640 [ 50.000478][ T7304] ? __kcsan_setup_watchpoint+0x6b/0x4a0 [ 50.009915][ T7304] ep_scan_ready_list.constprop.0+0x189/0x500 [ 50.016185][ T7304] ? ep_loop_check_proc+0x2f0/0x2f0 [ 50.021426][ T7304] ep_poll+0xe3/0x900 [ 50.025586][ T7304] ? wake_up_q+0x70/0x70 [ 50.030049][ T7304] do_epoll_wait+0x162/0x180 [ 50.034637][ T7304] __x64_sys_epoll_pwait+0xcd/0x180 [ 50.039900][ T7304] do_syscall_64+0xcc/0x370 [ 50.044533][ T7304] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 50.050894][ T7304] RIP: 0033:0x45b300 [ 50.055529][ T7304] Code: 0f 05 89 44 24 20 c3 cc cc cc 8b 7c 24 08 48 8b 74 24 10 8b 54 24 18 44 8b 54 24 1c 49 c7 c0 00 00 00 00 b8 19 01 00 00 0f 05 <89> 44 24 20 c3 cc cc cc cc cc cc cc cc cc cc cc 8b 7c 24 08 48 c7 [ 50.076807][ T7304] RSP: 002b:000000c4202f3860 EFLAGS: 00000246 ORIG_RAX: 0000000000000119 [ 50.085806][ T7304] RAX: ffffffffffffffda RBX: 00000000ffffffff RCX: 000000000045b300 [ 50.094499][ T7304] RDX: 0000000000000080 RSI: 000000c4202f38a0 RDI: 0000000000000004 [ 50.102781][ T7304] RBP: 000000c4202f3ea0 R08: 0000000000000000 R09: 0000000000000000 [ 50.110905][ T7304] R10: 00000000ffffffff R11: 0000000000000246 R12: 0000000000000200 [ 50.119880][ T7304] R13: ffffffffffffffff R14: 0000000000000002 R15: ffffffffffffffff [ 50.129721][ T7304] Kernel Offset: disabled [ 50.134224][ T7304] Rebooting in 86400 seconds..