[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 37.644281][ T25] audit: type=1800 audit(1571484138.211:25): pid=6930 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 37.671772][ T25] audit: type=1800 audit(1571484138.211:26): pid=6930 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 37.698478][ T25] audit: type=1800 audit(1571484138.211:27): pid=6930 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 '10.128.0.143' (ECDSA) to the list of known hosts. 2019/10/19 11:22:29 fuzzer started 2019/10/19 11:22:31 dialing manager at 10.128.0.105:43535 2019/10/19 11:22:31 syscalls: 2524 2019/10/19 11:22:31 code coverage: enabled 2019/10/19 11:22:31 comparison tracing: enabled 2019/10/19 11:22:31 extra coverage: extra coverage is not supported by the kernel 2019/10/19 11:22:31 setuid sandbox: enabled 2019/10/19 11:22:31 namespace sandbox: enabled 2019/10/19 11:22:31 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/19 11:22:31 fault injection: enabled 2019/10/19 11:22:31 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/19 11:22:31 net packet injection: enabled 2019/10/19 11:22:31 net device setup: enabled 2019/10/19 11:22:31 concurrency sanitizer: enabled syzkaller login: [ 51.121058][ T7099] ================================================================== [ 51.129313][ T7099] BUG: KCSAN: data-race in tcp_add_backlog / tcp_rcv_space_adjust [ 51.137118][ T7099] [ 51.139443][ T7099] read to 0xffff8881293d0a0c of 4 bytes by interrupt on cpu 0: [ 51.147151][ T7099] tcp_add_backlog+0x43/0xcc0 [ 51.151829][ T7099] tcp_v4_rcv+0x1a60/0x1bb0 [ 51.156396][ T7099] ip_protocol_deliver_rcu+0x4d/0x420 [ 51.161750][ T7099] ip_local_deliver_finish+0x110/0x140 [ 51.167188][ T7099] ip_local_deliver+0x133/0x210 [ 51.172097][ T7099] ip_rcv_finish+0x121/0x160 [ 51.176660][ T7099] ip_rcv+0x18f/0x1a0 [ 51.180729][ T7099] __netif_receive_skb_one_core+0xa7/0xe0 [ 51.186430][ T7099] __netif_receive_skb+0x37/0xf0 [ 51.191350][ T7099] netif_receive_skb_internal+0x59/0x190 [ 51.196960][ T7099] napi_gro_receive+0x28f/0x330 [ 51.201973][ T7099] receive_buf+0x284/0x30b0 [ 51.206474][ T7099] virtnet_poll+0x436/0x7d0 [ 51.210954][ T7099] net_rx_action+0x3ae/0xa90 [ 51.215529][ T7099] [ 51.217862][ T7099] write to 0xffff8881293d0a0c of 4 bytes by task 7099 on cpu 1: [ 51.225749][ T7099] tcp_rcv_space_adjust+0x40f/0x4c0 [ 51.230938][ T7099] tcp_recvmsg+0xdaa/0x1a30 [ 51.235446][ T7099] inet_recvmsg+0xbb/0x250 [ 51.239839][ T7099] sock_recvmsg+0x92/0xb0 [ 51.244153][ T7099] sock_read_iter+0x15f/0x1e0 [ 51.248981][ T7099] new_sync_read+0x389/0x4f0 [ 51.253545][ T7099] __vfs_read+0xb1/0xc0 [ 51.257675][ T7099] vfs_read+0x143/0x2c0 [ 51.261811][ T7099] ksys_read+0xd5/0x1b0 [ 51.265940][ T7099] __x64_sys_read+0x4c/0x60 [ 51.270430][ T7099] do_syscall_64+0xcc/0x370 [ 51.274908][ T7099] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 51.280777][ T7099] [ 51.283193][ T7099] Reported by Kernel Concurrency Sanitizer on: [ 51.289504][ T7099] CPU: 1 PID: 7099 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 51.296944][ T7099] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 51.307539][ T7099] ================================================================== [ 51.315575][ T7099] Kernel panic - not syncing: panic_on_warn set ... [ 51.322140][ T7099] CPU: 1 PID: 7099 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 51.329582][ T7099] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 51.339610][ T7099] Call Trace: [ 51.342882][ T7099] dump_stack+0xf5/0x159 [ 51.347102][ T7099] panic+0x210/0x640 [ 51.350988][ T7099] ? ksys_read+0xd5/0x1b0 [ 51.355301][ T7099] ? vprintk_func+0x8d/0x140 [ 51.359869][ T7099] kcsan_report.cold+0xc/0x10 [ 51.364637][ T7099] __kcsan_setup_watchpoint+0x32e/0x4a0 [ 51.370246][ T7099] __tsan_write4+0x32/0x40 [ 51.374638][ T7099] tcp_rcv_space_adjust+0x40f/0x4c0 [ 51.379827][ T7099] tcp_recvmsg+0xdaa/0x1a30 [ 51.384323][ T7099] ? __kcsan_setup_watchpoint+0x6b/0x4a0 [ 51.389951][ T7099] inet_recvmsg+0xbb/0x250 [ 51.394449][ T7099] ? __tsan_read8+0x2c/0x30 [ 51.398946][ T7099] ? inet_sendpage+0x100/0x100 [ 51.403718][ T7099] sock_recvmsg+0x92/0xb0 [ 51.408030][ T7099] sock_read_iter+0x15f/0x1e0 [ 51.412690][ T7099] new_sync_read+0x389/0x4f0 [ 51.417263][ T7099] __vfs_read+0xb1/0xc0 [ 51.421410][ T7099] vfs_read+0x143/0x2c0 [ 51.425553][ T7099] ksys_read+0xd5/0x1b0 [ 51.429936][ T7099] __x64_sys_read+0x4c/0x60 [ 51.434485][ T7099] do_syscall_64+0xcc/0x370 [ 51.438978][ T7099] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 51.444946][ T7099] RIP: 0033:0x47c530 [ 51.448825][ T7099] 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 [ 51.468412][ T7099] RSP: 002b:000000c42034f810 EFLAGS: 00000202 ORIG_RAX: 0000000000000000 [ 51.476808][ T7099] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000047c530 [ 51.485028][ T7099] RDX: 0000000000001000 RSI: 000000c420090000 RDI: 0000000000000003 [ 51.493062][ T7099] RBP: 000000c42034f868 R08: 0000000000000000 R09: 0000000000000000 [ 51.501019][ T7099] R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000004 [ 51.508977][ T7099] R13: ffffffffffffffff R14: 0000000000000002 R15: ffffffffffffffff [ 51.518825][ T7099] Kernel Offset: disabled [ 51.523149][ T7099] Rebooting in 86400 seconds..