[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 35.652777][ T26] audit: type=1800 audit(1572869086.621:25): pid=7065 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 35.679726][ T26] audit: type=1800 audit(1572869086.621:26): pid=7065 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 35.706494][ T26] audit: type=1800 audit(1572869086.621:27): pid=7065 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 '10.128.10.43' (ECDSA) to the list of known hosts. 2019/11/04 12:04:57 fuzzer started 2019/11/04 12:04:58 dialing manager at 10.128.0.105:43623 2019/11/04 12:04:59 syscalls: 2553 2019/11/04 12:04:59 code coverage: enabled 2019/11/04 12:04:59 comparison tracing: enabled 2019/11/04 12:04:59 extra coverage: extra coverage is not supported by the kernel 2019/11/04 12:04:59 setuid sandbox: enabled 2019/11/04 12:04:59 namespace sandbox: enabled 2019/11/04 12:04:59 Android sandbox: /sys/fs/selinux/policy does not exist 2019/11/04 12:04:59 fault injection: enabled 2019/11/04 12:04:59 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/11/04 12:04:59 net packet injection: enabled 2019/11/04 12:04:59 net device setup: enabled 2019/11/04 12:04:59 concurrency sanitizer: enabled 2019/11/04 12:04:59 devlink PCI setup: PCI device 0000:00:10.0 is not available 2019/11/04 12:05:00 adding functions to KCSAN blacklist: 'generic_fillattr' 'tcp_add_backlog' 'generic_permission' 'pipe_poll' '__hrtimer_run_queues' 'find_next_bit' 'ep_poll' '__tcp_select_window' 'tomoyo_supervisor' syzkaller login: [ 50.764391][ T7214] ================================================================== [ 50.772513][ T7214] BUG: KCSAN: data-race in tcp_poll / tcp_queue_rcv [ 50.779073][ T7214] [ 50.781383][ T7214] write to 0xffff8881241c85f8 of 4 bytes by interrupt on cpu 1: [ 50.789005][ T7214] tcp_queue_rcv+0xe9/0x380 [ 50.793485][ T7214] tcp_rcv_established+0xbf1/0xf50 [ 50.798573][ T7214] tcp_v4_do_rcv+0x381/0x4e0 [ 50.803142][ T7214] tcp_v4_rcv+0x19dc/0x1bb0 [ 50.808248][ T7214] ip_protocol_deliver_rcu+0x4d/0x420 [ 50.813597][ T7214] ip_local_deliver_finish+0x110/0x140 [ 50.819032][ T7214] ip_local_deliver+0x133/0x210 [ 50.823874][ T7214] ip_rcv_finish+0x121/0x160 [ 50.828449][ T7214] ip_rcv+0x18f/0x1a0 [ 50.832410][ T7214] __netif_receive_skb_one_core+0xa7/0xe0 [ 50.838482][ T7214] __netif_receive_skb+0x37/0xf0 [ 50.843393][ T7214] netif_receive_skb_internal+0x59/0x190 [ 50.849012][ T7214] napi_gro_receive+0x28f/0x330 [ 50.853855][ T7214] receive_buf+0x284/0x30b0 [ 50.858327][ T7214] [ 50.860648][ T7214] read to 0xffff8881241c85f8 of 4 bytes by task 7214 on cpu 0: [ 50.868167][ T7214] tcp_poll+0x204/0x6b0 [ 50.872315][ T7214] sock_poll+0xed/0x250 [ 50.876449][ T7214] ep_item_poll.isra.0+0x90/0x190 [ 50.881448][ T7214] ep_send_events_proc+0x113/0x590 [ 50.886547][ T7214] ep_scan_ready_list.constprop.0+0x189/0x500 [ 50.892591][ T7214] ep_poll+0xe3/0x900 [ 50.896552][ T7214] do_epoll_wait+0x162/0x180 [ 50.901118][ T7214] __x64_sys_epoll_pwait+0xcd/0x180 [ 50.906295][ T7214] do_syscall_64+0xcc/0x370 [ 50.910774][ T7214] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 50.916637][ T7214] [ 50.919546][ T7214] Reported by Kernel Concurrency Sanitizer on: [ 50.925687][ T7214] CPU: 0 PID: 7214 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 50.933115][ T7214] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 50.943160][ T7214] ================================================================== [ 50.951978][ T7214] Kernel panic - not syncing: panic_on_warn set ... [ 50.958553][ T7214] CPU: 0 PID: 7214 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 50.965982][ T7214] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 50.976098][ T7214] Call Trace: [ 50.979458][ T7214] dump_stack+0xf5/0x159 [ 50.983678][ T7214] panic+0x210/0x640 [ 50.987568][ T7214] ? do_syscall_64+0xcc/0x370 [ 50.992232][ T7214] ? vprintk_func+0x8d/0x140 [ 50.996801][ T7214] kcsan_report.cold+0xc/0x10 [ 51.001980][ T7214] __kcsan_setup_watchpoint+0x32e/0x4a0 [ 51.007523][ T7214] __tsan_read4+0x2c/0x30 [ 51.011836][ T7214] tcp_poll+0x204/0x6b0 [ 51.015975][ T7214] ? tcp_alloc_md5sig_pool+0x320/0x320 [ 51.021411][ T7214] sock_poll+0xed/0x250 [ 51.025544][ T7214] ? sock_read_iter+0x1e0/0x1e0 [ 51.030463][ T7214] ep_item_poll.isra.0+0x90/0x190 [ 51.035470][ T7214] ep_send_events_proc+0x113/0x590 [ 51.040573][ T7214] ? __schedule+0x319/0x640 [ 51.045054][ T7214] ? __kcsan_setup_watchpoint+0x6b/0x4a0 [ 51.050675][ T7214] ep_scan_ready_list.constprop.0+0x189/0x500 [ 51.056733][ T7214] ? ep_loop_check_proc+0x2f0/0x2f0 [ 51.061919][ T7214] ep_poll+0xe3/0x900 [ 51.065882][ T7214] ? wake_up_q+0x70/0x70 [ 51.070105][ T7214] do_epoll_wait+0x162/0x180 [ 51.074678][ T7214] __x64_sys_epoll_pwait+0xcd/0x180 [ 51.079858][ T7214] do_syscall_64+0xcc/0x370 [ 51.084518][ T7214] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 51.090907][ T7214] RIP: 0033:0x45b300 [ 51.094783][ T7214] 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 [ 51.114363][ T7214] RSP: 002b:00007ffc3b00b100 EFLAGS: 00000246 ORIG_RAX: 0000000000000119 [ 51.122760][ T7214] RAX: ffffffffffffffda RBX: 00000000ffffffff RCX: 000000000045b300 [ 51.130713][ T7214] RDX: 0000000000000080 RSI: 00007ffc3b00b140 RDI: 0000000000000004 [ 51.138676][ T7214] RBP: 00007ffc3b00b740 R08: 0000000000000000 R09: 0000000000000000 [ 51.146638][ T7214] R10: 00000000ffffffff R11: 0000000000000246 R12: 0000000000000008 [ 51.154594][ T7214] R13: ffffffffffffffff R14: 0000000000000008 R15: ffffffffffffffff [ 51.163845][ T7214] Kernel Offset: disabled [ 51.168440][ T7214] Rebooting in 86400 seconds..