[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 33.972778][ T25] audit: type=1800 audit(1571840433.550:25): pid=7041 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 34.017574][ T25] audit: type=1800 audit(1571840433.550:26): pid=7041 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 34.046575][ T25] audit: type=1800 audit(1571840433.560:27): pid=7041 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 '10.128.0.191' (ECDSA) to the list of known hosts. 2019/10/23 14:20:45 fuzzer started 2019/10/23 14:20:47 dialing manager at 10.128.0.105:40369 2019/10/23 14:20:47 syscalls: 2524 2019/10/23 14:20:47 code coverage: enabled 2019/10/23 14:20:47 comparison tracing: enabled 2019/10/23 14:20:47 extra coverage: extra coverage is not supported by the kernel 2019/10/23 14:20:47 setuid sandbox: enabled 2019/10/23 14:20:47 namespace sandbox: enabled 2019/10/23 14:20:47 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/23 14:20:47 fault injection: enabled 2019/10/23 14:20:47 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/23 14:20:47 net packet injection: enabled 2019/10/23 14:20:47 net device setup: enabled 2019/10/23 14:20:47 concurrency sanitizer: enabled 2019/10/23 14:20:48 adding functions to KCSAN blacklist: 'taskstats_exit' 'generic_write_end' 'common_perm_cond' 'tomoyo_supervisor' 'tcp_add_backlog' 'generic_fillattr' '__hrtimer_run_queues' syzkaller login: [ 49.315966][ T7210] ================================================================== [ 49.324088][ T7210] BUG: KCSAN: data-race in tcp_poll / tcp_queue_rcv [ 49.330686][ T7210] [ 49.332993][ T7210] write to 0xffff8881225e7778 of 4 bytes by interrupt on cpu 1: [ 49.340599][ T7210] tcp_queue_rcv+0xe9/0x380 [ 49.345078][ T7210] tcp_rcv_established+0xbf1/0xf50 [ 49.350165][ T7210] tcp_v4_do_rcv+0x381/0x4e0 [ 49.354730][ T7210] tcp_v4_rcv+0x19dc/0x1bb0 [ 49.359405][ T7210] ip_protocol_deliver_rcu+0x4d/0x420 [ 49.365276][ T7210] ip_local_deliver_finish+0x110/0x140 [ 49.370713][ T7210] ip_local_deliver+0x133/0x210 [ 49.375573][ T7210] ip_rcv_finish+0x121/0x160 [ 49.380137][ T7210] ip_rcv+0x18f/0x1a0 [ 49.384183][ T7210] __netif_receive_skb_one_core+0xa7/0xe0 [ 49.389875][ T7210] __netif_receive_skb+0x37/0xf0 [ 49.394796][ T7210] netif_receive_skb_internal+0x59/0x190 [ 49.400401][ T7210] napi_gro_receive+0x28f/0x330 [ 49.405225][ T7210] receive_buf+0x284/0x30b0 [ 49.409697][ T7210] [ 49.412005][ T7210] read to 0xffff8881225e7778 of 4 bytes by task 7210 on cpu 0: [ 49.419519][ T7210] tcp_poll+0x204/0x6b0 [ 49.423648][ T7210] sock_poll+0xed/0x250 [ 49.427778][ T7210] ep_item_poll.isra.0+0x90/0x190 [ 49.432777][ T7210] ep_send_events_proc+0x113/0x590 [ 49.437865][ T7210] ep_scan_ready_list.constprop.0+0x189/0x500 [ 49.443905][ T7210] ep_poll+0xe3/0x900 [ 49.447861][ T7210] do_epoll_wait+0x162/0x180 [ 49.452428][ T7210] __x64_sys_epoll_pwait+0xcd/0x180 [ 49.457602][ T7210] do_syscall_64+0xcc/0x370 [ 49.462091][ T7210] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 49.467971][ T7210] [ 49.470281][ T7210] Reported by Kernel Concurrency Sanitizer on: [ 49.476523][ T7210] CPU: 0 PID: 7210 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 49.483971][ T7210] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 49.494414][ T7210] ================================================================== [ 49.502450][ T7210] Kernel panic - not syncing: panic_on_warn set ... [ 49.509013][ T7210] CPU: 0 PID: 7210 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 49.516446][ T7210] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 49.526486][ T7210] Call Trace: [ 49.529757][ T7210] dump_stack+0xf5/0x159 [ 49.533975][ T7210] panic+0x210/0x640 [ 49.537953][ T7210] ? do_syscall_64+0xcc/0x370 [ 49.542957][ T7210] ? vprintk_func+0x8d/0x140 [ 49.547551][ T7210] kcsan_report.cold+0xc/0x10 [ 49.552220][ T7210] __kcsan_setup_watchpoint+0x32e/0x4a0 [ 49.557748][ T7210] __tsan_read4+0x2c/0x30 [ 49.562071][ T7210] tcp_poll+0x204/0x6b0 [ 49.566206][ T7210] ? tcp_alloc_md5sig_pool+0x320/0x320 [ 49.571644][ T7210] sock_poll+0xed/0x250 [ 49.575863][ T7210] ? sock_read_iter+0x1e0/0x1e0 [ 49.580692][ T7210] ep_item_poll.isra.0+0x90/0x190 [ 49.585705][ T7210] ep_send_events_proc+0x113/0x590 [ 49.590793][ T7210] ? __schedule+0x319/0x640 [ 49.595270][ T7210] ? __kcsan_setup_watchpoint+0x6b/0x4a0 [ 49.600893][ T7210] ep_scan_ready_list.constprop.0+0x189/0x500 [ 49.607056][ T7210] ? ep_loop_check_proc+0x2f0/0x2f0 [ 49.612235][ T7210] ep_poll+0xe3/0x900 [ 49.616208][ T7210] ? wake_up_q+0x70/0x70 [ 49.620455][ T7210] do_epoll_wait+0x162/0x180 [ 49.625027][ T7210] __x64_sys_epoll_pwait+0xcd/0x180 [ 49.630210][ T7210] do_syscall_64+0xcc/0x370 [ 49.634701][ T7210] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 49.640577][ T7210] RIP: 0033:0x45b300 [ 49.644471][ T7210] 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 [ 49.664048][ T7210] RSP: 002b:000000c4203b9860 EFLAGS: 00000246 ORIG_RAX: 0000000000000119 [ 49.672442][ T7210] RAX: ffffffffffffffda RBX: 00000000ffffffff RCX: 000000000045b300 [ 49.680399][ T7210] RDX: 0000000000000080 RSI: 000000c4203b98a0 RDI: 0000000000000004 [ 49.688346][ T7210] RBP: 000000c4203b9ea0 R08: 0000000000000000 R09: 0000000000000000 [ 49.696304][ T7210] R10: 00000000ffffffff R11: 0000000000000246 R12: 000000c42017c8d8 [ 49.704265][ T7210] R13: 000000000000000f R14: 0000000000c15060 R15: 0000000000000221 [ 49.713506][ T7210] Kernel Offset: disabled [ 49.717829][ T7210] Rebooting in 86400 seconds..