[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 41.018949][ T23] audit: type=1800 audit(1571787037.373:25): pid=7055 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 41.038776][ T23] audit: type=1800 audit(1571787037.373:26): pid=7055 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 41.060658][ T23] audit: type=1800 audit(1571787037.373:27): pid=7055 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 '10.128.0.224' (ECDSA) to the list of known hosts. 2019/10/22 23:30:48 fuzzer started 2019/10/22 23:30:50 dialing manager at 10.128.0.105:33369 2019/10/22 23:30:50 syscalls: 2524 2019/10/22 23:30:50 code coverage: enabled 2019/10/22 23:30:50 comparison tracing: enabled 2019/10/22 23:30:50 extra coverage: extra coverage is not supported by the kernel 2019/10/22 23:30:50 setuid sandbox: enabled 2019/10/22 23:30:50 namespace sandbox: enabled 2019/10/22 23:30:50 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/22 23:30:50 fault injection: enabled 2019/10/22 23:30:50 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/22 23:30:50 net packet injection: enabled 2019/10/22 23:30:50 net device setup: enabled 2019/10/22 23:30:50 concurrency sanitizer: enabled syzkaller login: [ 54.265476][ T7206] ================================================================== [ 54.273618][ T7206] BUG: KCSAN: data-race in tcp_poll / tcp_queue_rcv [ 54.280190][ T7206] [ 54.282543][ T7206] write to 0xffff88811e0bce78 of 4 bytes by interrupt on cpu 0: [ 54.290158][ T7206] tcp_queue_rcv+0x180/0x380 [ 54.294740][ T7206] tcp_rcv_established+0xbf1/0xf50 [ 54.299838][ T7206] tcp_v4_do_rcv+0x381/0x4e0 [ 54.304424][ T7206] tcp_v4_rcv+0x19dc/0x1bb0 [ 54.308914][ T7206] ip_protocol_deliver_rcu+0x4d/0x420 [ 54.314277][ T7206] ip_local_deliver_finish+0x110/0x140 [ 54.319721][ T7206] ip_local_deliver+0x133/0x210 [ 54.324555][ T7206] ip_rcv_finish+0x121/0x160 [ 54.329129][ T7206] ip_rcv+0x18f/0x1a0 [ 54.333095][ T7206] __netif_receive_skb_one_core+0xa7/0xe0 [ 54.338804][ T7206] __netif_receive_skb+0x37/0xf0 [ 54.343729][ T7206] netif_receive_skb_internal+0x59/0x190 [ 54.349421][ T7206] napi_gro_receive+0x28f/0x330 [ 54.354251][ T7206] receive_buf+0x284/0x30b0 [ 54.358723][ T7206] [ 54.361032][ T7206] read to 0xffff88811e0bce78 of 4 bytes by task 7206 on cpu 1: [ 54.368659][ T7206] tcp_poll+0x204/0x6b0 [ 54.372850][ T7206] sock_poll+0xed/0x250 [ 54.376992][ T7206] ep_item_poll.isra.0+0x90/0x190 [ 54.382011][ T7206] ep_send_events_proc+0x113/0x590 [ 54.387106][ T7206] ep_scan_ready_list.constprop.0+0x189/0x500 [ 54.393150][ T7206] ep_poll+0xe3/0x900 [ 54.397113][ T7206] do_epoll_wait+0x162/0x180 [ 54.401678][ T7206] __x64_sys_epoll_pwait+0xcd/0x180 [ 54.406855][ T7206] do_syscall_64+0xcc/0x370 [ 54.411335][ T7206] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 54.417193][ T7206] [ 54.419505][ T7206] Reported by Kernel Concurrency Sanitizer on: [ 54.425642][ T7206] CPU: 1 PID: 7206 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 54.433079][ T7206] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 54.443118][ T7206] ================================================================== [ 54.451151][ T7206] Kernel panic - not syncing: panic_on_warn set ... [ 54.457715][ T7206] CPU: 1 PID: 7206 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 54.465158][ T7206] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 54.475205][ T7206] Call Trace: [ 54.479175][ T7206] dump_stack+0xf5/0x159 [ 54.483404][ T7206] panic+0x210/0x640 [ 54.487276][ T7206] ? do_syscall_64+0xcc/0x370 [ 54.491940][ T7206] ? vprintk_func+0x8d/0x140 [ 54.496595][ T7206] kcsan_report.cold+0xc/0x10 [ 54.501250][ T7206] __kcsan_setup_watchpoint+0x32e/0x4a0 [ 54.506794][ T7206] ? tcp_recvmsg+0x65b/0x1a30 [ 54.511456][ T7206] __tsan_read4+0x2c/0x30 [ 54.515767][ T7206] tcp_poll+0x204/0x6b0 [ 54.519901][ T7206] ? tcp_alloc_md5sig_pool+0x320/0x320 [ 54.525337][ T7206] sock_poll+0xed/0x250 [ 54.529471][ T7206] ? sock_read_iter+0x1e0/0x1e0 [ 54.534305][ T7206] ep_item_poll.isra.0+0x90/0x190 [ 54.539308][ T7206] ep_send_events_proc+0x113/0x590 [ 54.544397][ T7206] ? __kcsan_setup_watchpoint+0x6b/0x4a0 [ 54.550116][ T7206] ep_scan_ready_list.constprop.0+0x189/0x500 [ 54.556161][ T7206] ? ep_loop_check_proc+0x2f0/0x2f0 [ 54.561337][ T7206] ep_poll+0xe3/0x900 [ 54.565293][ T7206] ? __fget+0xb8/0x1d0 [ 54.569352][ T7206] ? __kcsan_setup_watchpoint+0x6b/0x4a0 [ 54.574961][ T7206] ? __fget_light+0xaf/0x190 [ 54.579528][ T7206] do_epoll_wait+0x162/0x180 [ 54.584106][ T7206] __x64_sys_epoll_pwait+0xcd/0x180 [ 54.589281][ T7206] do_syscall_64+0xcc/0x370 [ 54.593761][ T7206] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 54.599634][ T7206] RIP: 0033:0x45b300 [ 54.603517][ T7206] 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 [ 54.623105][ T7206] RSP: 002b:000000c42015b860 EFLAGS: 00000246 ORIG_RAX: 0000000000000119 [ 54.631489][ T7206] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000045b300 [ 54.639436][ T7206] RDX: 0000000000000080 RSI: 000000c42015b8a0 RDI: 0000000000000004 [ 54.647380][ T7206] RBP: 000000c42015bea0 R08: 0000000000000000 R09: 0000000000000000 [ 54.655336][ T7206] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000020 [ 54.663280][ T7206] R13: ffffffffffffffff R14: 0000000000000004 R15: ffffffffffffffff [ 54.672769][ T7206] Kernel Offset: disabled [ 54.677099][ T7206] Rebooting in 86400 seconds..