[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 35.868200][ T25] audit: type=1800 audit(1571766688.421:25): pid=7032 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 35.919835][ T25] audit: type=1800 audit(1571766688.421:26): pid=7032 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 35.941494][ T25] audit: type=1800 audit(1571766688.421:27): pid=7032 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 '10.128.0.2' (ECDSA) to the list of known hosts. 2019/10/22 17:51:38 fuzzer started 2019/10/22 17:51:39 dialing manager at 10.128.0.105:33369 2019/10/22 17:51:39 syscalls: 2524 2019/10/22 17:51:39 code coverage: enabled 2019/10/22 17:51:39 comparison tracing: enabled 2019/10/22 17:51:39 extra coverage: extra coverage is not supported by the kernel 2019/10/22 17:51:39 setuid sandbox: enabled 2019/10/22 17:51:39 namespace sandbox: enabled 2019/10/22 17:51:39 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/22 17:51:39 fault injection: enabled 2019/10/22 17:51:39 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/22 17:51:39 net packet injection: enabled 2019/10/22 17:51:39 net device setup: enabled 2019/10/22 17:51:39 concurrency sanitizer: enabled syzkaller login: [ 47.439156][ T7184] ================================================================== [ 47.447292][ T7184] BUG: KCSAN: data-race in tcp_add_backlog / tcp_grow_window.isra.0 [ 47.455253][ T7184] [ 47.457567][ T7184] write to 0xffff88812936aa2c of 4 bytes by interrupt on cpu 1: [ 47.465181][ T7184] tcp_add_backlog+0x4a0/0xcc0 [ 47.469942][ T7184] tcp_v4_rcv+0x1a60/0x1bb0 [ 47.474432][ T7184] ip_protocol_deliver_rcu+0x4d/0x420 [ 47.479783][ T7184] ip_local_deliver_finish+0x110/0x140 [ 47.485225][ T7184] ip_local_deliver+0x133/0x210 [ 47.490050][ T7184] ip_rcv_finish+0x121/0x160 [ 47.494615][ T7184] ip_rcv+0x18f/0x1a0 [ 47.498575][ T7184] __netif_receive_skb_one_core+0xa7/0xe0 [ 47.504269][ T7184] __netif_receive_skb+0x37/0xf0 [ 47.509197][ T7184] netif_receive_skb_internal+0x59/0x190 [ 47.514929][ T7184] napi_gro_receive+0x28f/0x330 [ 47.519773][ T7184] receive_buf+0x284/0x30b0 [ 47.524253][ T7184] virtnet_poll+0x436/0x7d0 [ 47.528754][ T7184] net_rx_action+0x3ae/0xa90 [ 47.533314][ T7184] [ 47.535638][ T7184] read to 0xffff88812936aa2c of 4 bytes by task 7184 on cpu 0: [ 47.543156][ T7184] tcp_grow_window.isra.0+0x6b/0x480 [ 47.548429][ T7184] tcp_event_data_recv+0x68f/0x990 [ 47.553534][ T7184] tcp_rcv_established+0xbfe/0xf50 [ 47.558624][ T7184] tcp_v4_do_rcv+0x381/0x4e0 [ 47.563204][ T7184] __release_sock+0x135/0x1e0 [ 47.567870][ T7184] release_sock+0x61/0x160 [ 47.572268][ T7184] tcp_recvmsg+0x63b/0x1a30 [ 47.576751][ T7184] inet_recvmsg+0xbb/0x250 [ 47.581147][ T7184] sock_recvmsg+0x92/0xb0 [ 47.585468][ T7184] sock_read_iter+0x15f/0x1e0 [ 47.590170][ T7184] new_sync_read+0x389/0x4f0 [ 47.594737][ T7184] __vfs_read+0xb1/0xc0 [ 47.598898][ T7184] vfs_read+0x143/0x2c0 [ 47.603806][ T7184] [ 47.606107][ T7184] Reported by Kernel Concurrency Sanitizer on: [ 47.612236][ T7184] CPU: 0 PID: 7184 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 47.619689][ T7184] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 47.629749][ T7184] ================================================================== [ 47.637808][ T7184] Kernel panic - not syncing: panic_on_warn set ... [ 47.644378][ T7184] CPU: 0 PID: 7184 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 47.651855][ T7184] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 47.662191][ T7184] Call Trace: [ 47.665555][ T7184] dump_stack+0xf5/0x159 [ 47.669797][ T7184] panic+0x210/0x640 [ 47.673835][ T7184] ? sock_recvmsg+0x92/0xb0 [ 47.678337][ T7184] ? vprintk_func+0x8d/0x140 [ 47.682934][ T7184] kcsan_report.cold+0xc/0x10 [ 47.687597][ T7184] __kcsan_setup_watchpoint+0x32e/0x4a0 [ 47.693125][ T7184] __tsan_read4+0x2c/0x30 [ 47.697450][ T7184] tcp_grow_window.isra.0+0x6b/0x480 [ 47.702710][ T7184] ? __kcsan_setup_watchpoint+0x6b/0x4a0 [ 47.708582][ T7184] tcp_event_data_recv+0x68f/0x990 [ 47.713682][ T7184] tcp_rcv_established+0xbfe/0xf50 [ 47.718772][ T7184] ? ipv4_dst_check+0xc6/0xf0 [ 47.723451][ T7184] tcp_v4_do_rcv+0x381/0x4e0 [ 47.728129][ T7184] __release_sock+0x135/0x1e0 [ 47.732813][ T7184] release_sock+0x61/0x160 [ 47.737208][ T7184] tcp_recvmsg+0x63b/0x1a30 [ 47.741696][ T7184] inet_recvmsg+0xbb/0x250 [ 47.746088][ T7184] ? __tsan_read8+0x2c/0x30 [ 47.750567][ T7184] ? inet_sendpage+0x100/0x100 [ 47.755309][ T7184] sock_recvmsg+0x92/0xb0 [ 47.759617][ T7184] sock_read_iter+0x15f/0x1e0 [ 47.764274][ T7184] new_sync_read+0x389/0x4f0 [ 47.768850][ T7184] __vfs_read+0xb1/0xc0 [ 47.772983][ T7184] vfs_read+0x143/0x2c0 [ 47.777173][ T7184] ksys_read+0xd5/0x1b0 [ 47.781329][ T7184] __x64_sys_read+0x4c/0x60 [ 47.785819][ T7184] do_syscall_64+0xcc/0x370 [ 47.790302][ T7184] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 47.796166][ T7184] RIP: 0033:0x47c530 [ 47.800047][ T7184] 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 [ 47.820417][ T7184] RSP: 002b:000000c4201497d8 EFLAGS: 00000212 ORIG_RAX: 0000000000000000 [ 47.828810][ T7184] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000047c530 [ 47.836849][ T7184] RDX: 0000000000001000 RSI: 000000c4203e8000 RDI: 0000000000000003 [ 47.844813][ T7184] RBP: 000000c420149830 R08: 0000000000000000 R09: 0000000000000000 [ 47.852925][ T7184] R10: 0000000000000000 R11: 0000000000000212 R12: 0000000000000008 [ 47.860888][ T7184] R13: ffffffffffffffff R14: 0000000000000002 R15: ffffffffffffffff [ 47.870337][ T7184] Kernel Offset: disabled [ 47.874665][ T7184] Rebooting in 86400 seconds..