[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 34.741703][ T26] audit: type=1800 audit(1571759421.871:25): pid=7009 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 34.768725][ T26] audit: type=1800 audit(1571759421.871:26): pid=7009 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 34.816644][ T26] audit: type=1800 audit(1571759421.871:27): pid=7009 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 '10.128.0.68' (ECDSA) to the list of known hosts. 2019/10/22 15:50:32 fuzzer started 2019/10/22 15:50:33 dialing manager at 10.128.0.105:33369 2019/10/22 15:50:34 syscalls: 2524 2019/10/22 15:50:34 code coverage: enabled 2019/10/22 15:50:34 comparison tracing: enabled 2019/10/22 15:50:34 extra coverage: extra coverage is not supported by the kernel 2019/10/22 15:50:34 setuid sandbox: enabled 2019/10/22 15:50:34 namespace sandbox: enabled 2019/10/22 15:50:34 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/22 15:50:34 fault injection: enabled 2019/10/22 15:50:34 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/22 15:50:34 net packet injection: enabled 2019/10/22 15:50:34 net device setup: enabled 2019/10/22 15:50:34 concurrency sanitizer: enabled syzkaller login: [ 47.255865][ T7172] ================================================================== [ 47.264163][ T7172] BUG: KCSAN: data-race in tcp_add_backlog / tcp_recvmsg [ 47.271308][ T7172] [ 47.273625][ T7172] write to 0xffff8881251e09f8 of 8 bytes by interrupt on cpu 1: [ 47.281249][ T7172] tcp_add_backlog+0x45a/0xcc0 [ 47.286157][ T7172] tcp_v4_rcv+0x1a60/0x1bb0 [ 47.290648][ T7172] ip_protocol_deliver_rcu+0x4d/0x420 [ 47.296003][ T7172] ip_local_deliver_finish+0x110/0x140 [ 47.301449][ T7172] ip_local_deliver+0x133/0x210 [ 47.306283][ T7172] ip_rcv_finish+0x121/0x160 [ 47.310858][ T7172] ip_rcv+0x18f/0x1a0 [ 47.314821][ T7172] __netif_receive_skb_one_core+0xa7/0xe0 [ 47.320528][ T7172] __netif_receive_skb+0x37/0xf0 [ 47.325488][ T7172] netif_receive_skb_internal+0x59/0x190 [ 47.331218][ T7172] napi_gro_receive+0x28f/0x330 [ 47.336079][ T7172] receive_buf+0x284/0x30b0 [ 47.340565][ T7172] virtnet_poll+0x436/0x7d0 [ 47.345050][ T7172] net_rx_action+0x3ae/0xa90 [ 47.349614][ T7172] [ 47.351967][ T7172] read to 0xffff8881251e09f8 of 8 bytes by task 7172 on cpu 0: [ 47.359492][ T7172] tcp_recvmsg+0x470/0x1a30 [ 47.364005][ T7172] inet_recvmsg+0xbb/0x250 [ 47.368403][ T7172] sock_recvmsg+0x92/0xb0 [ 47.372718][ T7172] sock_read_iter+0x15f/0x1e0 [ 47.377375][ T7172] new_sync_read+0x389/0x4f0 [ 47.381952][ T7172] __vfs_read+0xb1/0xc0 [ 47.386088][ T7172] vfs_read+0x143/0x2c0 [ 47.390228][ T7172] ksys_read+0xd5/0x1b0 [ 47.394371][ T7172] __x64_sys_read+0x4c/0x60 [ 47.398859][ T7172] do_syscall_64+0xcc/0x370 [ 47.403345][ T7172] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 47.409217][ T7172] [ 47.411526][ T7172] Reported by Kernel Concurrency Sanitizer on: [ 47.417695][ T7172] CPU: 0 PID: 7172 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 47.425130][ T7172] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 47.435201][ T7172] ================================================================== [ 47.443245][ T7172] Kernel panic - not syncing: panic_on_warn set ... [ 47.449827][ T7172] CPU: 0 PID: 7172 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 47.457258][ T7172] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 47.467325][ T7172] Call Trace: [ 47.470604][ T7172] dump_stack+0xf5/0x159 [ 47.474829][ T7172] panic+0x210/0x640 [ 47.478715][ T7172] ? __x64_sys_read+0x4c/0x60 [ 47.483409][ T7172] ? vprintk_func+0x8d/0x140 [ 47.488019][ T7172] kcsan_report.cold+0xc/0x10 [ 47.492681][ T7172] __kcsan_setup_watchpoint+0x32e/0x4a0 [ 47.498211][ T7172] __tsan_read8+0x2c/0x30 [ 47.502543][ T7172] tcp_recvmsg+0x470/0x1a30 [ 47.507042][ T7172] inet_recvmsg+0xbb/0x250 [ 47.511471][ T7172] ? __tsan_read8+0x2c/0x30 [ 47.515956][ T7172] ? inet_sendpage+0x100/0x100 [ 47.520708][ T7172] sock_recvmsg+0x92/0xb0 [ 47.525022][ T7172] sock_read_iter+0x15f/0x1e0 [ 47.529684][ T7172] new_sync_read+0x389/0x4f0 [ 47.534263][ T7172] __vfs_read+0xb1/0xc0 [ 47.538431][ T7172] vfs_read+0x143/0x2c0 [ 47.542575][ T7172] ksys_read+0xd5/0x1b0 [ 47.546831][ T7172] __x64_sys_read+0x4c/0x60 [ 47.551420][ T7172] do_syscall_64+0xcc/0x370 [ 47.555909][ T7172] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 47.561783][ T7172] RIP: 0033:0x47c530 [ 47.565667][ T7172] Code: 8b 7c 24 10 48 8b 74 24 18 48 8b 54 24 20 49 c7 c2 00 00 00 00 49 c7 c0 00 00 00 00 49 c7 c1 00 00 00 00 48 8b 44 24 08 0f 05 <48> 3d 01 f0 ff ff 76 20 48 c7 44 24 28 ff ff ff ff 48 c7 44 24 30 [ 47.585258][ T7172] RSP: 002b:000000c4204ef7d8 EFLAGS: 00000212 ORIG_RAX: 0000000000000000 [ 47.593653][ T7172] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000047c530 [ 47.601783][ T7172] RDX: 0000000000001000 RSI: 000000c4203b2000 RDI: 0000000000000003 [ 47.609746][ T7172] RBP: 000000c4204ef830 R08: 0000000000000000 R09: 0000000000000000 [ 47.617704][ T7172] R10: 0000000000000000 R11: 0000000000000212 R12: 0000000000000010 [ 47.625661][ T7172] R13: ffffffffffffffff R14: 0000000000000002 R15: ffffffffffffffff [ 47.635414][ T7172] Kernel Offset: disabled [ 47.639747][ T7172] Rebooting in 86400 seconds..