[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 34.924253][ T26] audit: type=1800 audit(1571768272.938:25): 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 [ 34.967705][ T26] audit: type=1800 audit(1571768272.938:26): 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 [ 34.992225][ T26] audit: type=1800 audit(1571768272.938:27): 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 '10.128.1.28' (ECDSA) to the list of known hosts. 2019/10/22 18:18:02 fuzzer started 2019/10/22 18:18:03 dialing manager at 10.128.0.105:33369 2019/10/22 18:18:03 syscalls: 2524 2019/10/22 18:18:03 code coverage: enabled 2019/10/22 18:18:03 comparison tracing: enabled 2019/10/22 18:18:03 extra coverage: extra coverage is not supported by the kernel 2019/10/22 18:18:03 setuid sandbox: enabled 2019/10/22 18:18:03 namespace sandbox: enabled 2019/10/22 18:18:03 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/22 18:18:03 fault injection: enabled 2019/10/22 18:18:03 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/22 18:18:03 net packet injection: enabled 2019/10/22 18:18:03 net device setup: enabled 2019/10/22 18:18:03 concurrency sanitizer: enabled syzkaller login: [ 45.724814][ T7157] ================================================================== [ 45.732927][ T7157] BUG: KCSAN: data-race in __tcp_select_window / tcp_add_backlog [ 45.740651][ T7157] [ 45.742955][ T7157] write to 0xffff8881265fe9ec of 4 bytes by interrupt on cpu 1: [ 45.750586][ T7157] tcp_add_backlog+0x4a0/0xcc0 [ 45.755324][ T7157] tcp_v4_rcv+0x1a60/0x1bb0 [ 45.759802][ T7157] ip_protocol_deliver_rcu+0x4d/0x420 [ 45.765145][ T7157] ip_local_deliver_finish+0x110/0x140 [ 45.770580][ T7157] ip_local_deliver+0x133/0x210 [ 45.775401][ T7157] ip_rcv_finish+0x121/0x160 [ 45.779962][ T7157] ip_rcv+0x18f/0x1a0 [ 45.783920][ T7157] __netif_receive_skb_one_core+0xa7/0xe0 [ 45.789623][ T7157] __netif_receive_skb+0x37/0xf0 [ 45.794551][ T7157] netif_receive_skb_internal+0x59/0x190 [ 45.800158][ T7157] napi_gro_receive+0x28f/0x330 [ 45.804983][ T7157] receive_buf+0x284/0x30b0 [ 45.809461][ T7157] virtnet_poll+0x436/0x7d0 [ 45.813937][ T7157] net_rx_action+0x3ae/0xa90 [ 45.818505][ T7157] [ 45.820811][ T7157] read to 0xffff8881265fe9ec of 4 bytes by task 7157 on cpu 0: [ 45.828327][ T7157] __tcp_select_window+0x6b/0x4d0 [ 45.833327][ T7157] __tcp_transmit_skb+0x700/0x1d60 [ 45.838409][ T7157] __tcp_send_ack+0x246/0x300 [ 45.843057][ T7157] tcp_send_ack+0x34/0x40 [ 45.847360][ T7157] tcp_cleanup_rbuf+0x130/0x360 [ 45.852185][ T7157] tcp_recvmsg+0x633/0x1a30 [ 45.856772][ T7157] inet_recvmsg+0xbb/0x250 [ 45.861252][ T7157] sock_recvmsg+0x92/0xb0 [ 45.865585][ T7157] sock_read_iter+0x15f/0x1e0 [ 45.870236][ T7157] new_sync_read+0x389/0x4f0 [ 45.874799][ T7157] __vfs_read+0xb1/0xc0 [ 45.878926][ T7157] vfs_read+0x143/0x2c0 [ 45.883056][ T7157] ksys_read+0xd5/0x1b0 [ 45.887179][ T7157] [ 45.889479][ T7157] Reported by Kernel Concurrency Sanitizer on: [ 45.895607][ T7157] CPU: 0 PID: 7157 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 45.903035][ T7157] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 45.913196][ T7157] ================================================================== [ 45.921226][ T7157] Kernel panic - not syncing: panic_on_warn set ... [ 45.927787][ T7157] CPU: 0 PID: 7157 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 45.935209][ T7157] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 45.945236][ T7157] Call Trace: [ 45.948505][ T7157] dump_stack+0xf5/0x159 [ 45.952725][ T7157] panic+0x210/0x640 [ 45.956595][ T7157] ? sock_read_iter+0x15f/0x1e0 [ 45.961418][ T7157] ? vprintk_func+0x8d/0x140 [ 45.965985][ T7157] kcsan_report.cold+0xc/0x10 [ 45.970639][ T7157] __kcsan_setup_watchpoint+0x32e/0x4a0 [ 45.976168][ T7157] __tsan_read4+0x2c/0x30 [ 45.980470][ T7157] __tcp_select_window+0x6b/0x4d0 [ 45.985472][ T7157] __tcp_transmit_skb+0x700/0x1d60 [ 45.990565][ T7157] __tcp_send_ack+0x246/0x300 [ 45.995218][ T7157] tcp_send_ack+0x34/0x40 [ 45.999525][ T7157] tcp_cleanup_rbuf+0x130/0x360 [ 46.004365][ T7157] tcp_recvmsg+0x633/0x1a30 [ 46.008852][ T7157] inet_recvmsg+0xbb/0x250 [ 46.013255][ T7157] ? __tsan_read8+0x2c/0x30 [ 46.017731][ T7157] ? inet_sendpage+0x100/0x100 [ 46.022500][ T7157] sock_recvmsg+0x92/0xb0 [ 46.026812][ T7157] sock_read_iter+0x15f/0x1e0 [ 46.031486][ T7157] new_sync_read+0x389/0x4f0 [ 46.036057][ T7157] __vfs_read+0xb1/0xc0 [ 46.040188][ T7157] vfs_read+0x143/0x2c0 [ 46.044328][ T7157] ksys_read+0xd5/0x1b0 [ 46.048478][ T7157] __x64_sys_read+0x4c/0x60 [ 46.052961][ T7157] do_syscall_64+0xcc/0x370 [ 46.057440][ T7157] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 46.063304][ T7157] RIP: 0033:0x47c530 [ 46.067174][ T7157] 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 [ 46.086747][ T7157] RSP: 002b:000000c4204ef810 EFLAGS: 00000202 ORIG_RAX: 0000000000000000 [ 46.095130][ T7157] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000047c530 [ 46.103074][ T7157] RDX: 0000000000001000 RSI: 000000c42006c000 RDI: 0000000000000003 [ 46.111019][ T7157] RBP: 000000c4204ef868 R08: 0000000000000000 R09: 0000000000000000 [ 46.119051][ T7157] R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000004 [ 46.127003][ T7157] R13: ffffffffffffffff R14: 0000000000000040 R15: ffffffffffffffff [ 46.136130][ T7157] Kernel Offset: disabled [ 46.140446][ T7157] Rebooting in 86400 seconds..