[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 35.111906][ T25] audit: type=1800 audit(1570201760.791:25): pid=7129 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c[ 35.315584][ T25] audit: type=1800 audit(1570201760.991:26): pid=7129 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 35.342662][ T25] audit: type=1800 audit(1570201761.021:27): pid=7129 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 OpenBSD Secure Shell server: sshd[?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 Warning: Permanently added '10.128.0.19' (ECDSA) to the list of known hosts. 2019/10/04 15:09:28 fuzzer started 2019/10/04 15:09:29 dialing manager at 10.128.0.105:44881 2019/10/04 15:09:29 syscalls: 2523 2019/10/04 15:09:29 code coverage: enabled 2019/10/04 15:09:29 comparison tracing: enabled 2019/10/04 15:09:29 extra coverage: extra coverage is not supported by the kernel 2019/10/04 15:09:29 setuid sandbox: enabled 2019/10/04 15:09:29 namespace sandbox: enabled 2019/10/04 15:09:29 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/04 15:09:29 fault injection: enabled 2019/10/04 15:09:29 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/04 15:09:29 net packet injection: enabled 2019/10/04 15:09:29 net device setup: enabled 2019/10/04 15:09:29 concurrency sanitizer: enabled syzkaller login: [ 44.273115][ T7292] ================================================================== [ 44.281429][ T7292] BUG: KCSAN: data-race in tcp_add_backlog / tcp_grow_window.isra.0 [ 44.289510][ T7292] [ 44.291969][ T7292] write to 0xffff88812665f32c of 4 bytes by interrupt on cpu 1: [ 44.299679][ T7292] tcp_add_backlog+0x4a0/0xcc0 [ 44.304470][ T7292] tcp_v4_rcv+0x1aba/0x1bf0 [ 44.308961][ T7292] ip_protocol_deliver_rcu+0x51/0x470 [ 44.314466][ T7292] ip_local_deliver_finish+0x110/0x140 [ 44.319941][ T7292] ip_local_deliver+0x133/0x210 [ 44.324777][ T7292] ip_rcv_finish+0x121/0x160 [ 44.329343][ T7292] ip_rcv+0x18f/0x1a0 [ 44.333308][ T7292] __netif_receive_skb_one_core+0xa7/0xe0 [ 44.339009][ T7292] __netif_receive_skb+0x37/0xf0 [ 44.343944][ T7292] netif_receive_skb_internal+0x59/0x190 [ 44.349562][ T7292] napi_gro_receive+0x28f/0x330 [ 44.354401][ T7292] receive_buf+0x284/0x30b0 [ 44.359005][ T7292] virtnet_poll+0x436/0x7d0 [ 44.363501][ T7292] net_rx_action+0x3ae/0xa50 [ 44.368066][ T7292] [ 44.370468][ T7292] read to 0xffff88812665f32c of 4 bytes by task 7292 on cpu 0: [ 44.378001][ T7292] tcp_grow_window.isra.0+0x6b/0x480 [ 44.383273][ T7292] tcp_event_data_recv+0x68f/0x990 [ 44.388379][ T7292] tcp_rcv_established+0xbfe/0xf50 [ 44.393480][ T7292] tcp_v4_do_rcv+0x381/0x4e0 [ 44.398072][ T7292] __release_sock+0x135/0x1e0 [ 44.402749][ T7292] release_sock+0x61/0x160 [ 44.407141][ T7292] tcp_recvmsg+0x63b/0x1a30 [ 44.411624][ T7292] inet_recvmsg+0xbb/0x250 [ 44.416030][ T7292] sock_recvmsg+0x92/0xb0 [ 44.420334][ T7292] sock_read_iter+0x15f/0x1e0 [ 44.424987][ T7292] new_sync_read+0x389/0x4f0 [ 44.429553][ T7292] __vfs_read+0xb1/0xc0 [ 44.433697][ T7292] vfs_read+0x143/0x2c0 [ 44.437834][ T7292] [ 44.440138][ T7292] Reported by Kernel Concurrency Sanitizer on: [ 44.446273][ T7292] CPU: 0 PID: 7292 Comm: syz-fuzzer Not tainted 5.3.0+ #0 [ 44.453355][ T7292] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 44.463399][ T7292] ================================================================== [ 44.471444][ T7292] Kernel panic - not syncing: panic_on_warn set ... [ 44.478010][ T7292] CPU: 0 PID: 7292 Comm: syz-fuzzer Not tainted 5.3.0+ #0 [ 44.485091][ T7292] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 44.495120][ T7292] Call Trace: [ 44.498393][ T7292] dump_stack+0xf5/0x159 [ 44.502618][ T7292] panic+0x209/0x639 [ 44.506497][ T7292] ? vprintk_func+0x8d/0x140 [ 44.511124][ T7292] kcsan_report.cold+0x57/0xeb [ 44.515878][ T7292] __kcsan_setup_watchpoint+0x342/0x500 [ 44.521412][ T7292] __tsan_read4+0x2c/0x30 [ 44.525733][ T7292] tcp_grow_window.isra.0+0x6b/0x480 [ 44.531119][ T7292] tcp_event_data_recv+0x68f/0x990 [ 44.536226][ T7292] tcp_rcv_established+0xbfe/0xf50 [ 44.541335][ T7292] ? ipv4_dst_check+0xc6/0xf0 [ 44.546011][ T7292] tcp_v4_do_rcv+0x381/0x4e0 [ 44.550596][ T7292] __release_sock+0x135/0x1e0 [ 44.555352][ T7292] release_sock+0x61/0x160 [ 44.559821][ T7292] tcp_recvmsg+0x63b/0x1a30 [ 44.564326][ T7292] inet_recvmsg+0xbb/0x250 [ 44.568747][ T7292] ? __tsan_read8+0x2c/0x30 [ 44.573240][ T7292] ? inet_sendpage+0x100/0x100 [ 44.577991][ T7292] sock_recvmsg+0x92/0xb0 [ 44.582300][ T7292] sock_read_iter+0x15f/0x1e0 [ 44.586974][ T7292] new_sync_read+0x389/0x4f0 [ 44.591555][ T7292] __vfs_read+0xb1/0xc0 [ 44.595697][ T7292] vfs_read+0x143/0x2c0 [ 44.599934][ T7292] ksys_read+0xd5/0x1b0 [ 44.604079][ T7292] __x64_sys_read+0x4c/0x60 [ 44.608571][ T7292] do_syscall_64+0xcf/0x2f0 [ 44.613060][ T7292] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 44.618947][ T7292] RIP: 0033:0x47c530 [ 44.622826][ T7292] 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 [ 44.642413][ T7292] RSP: 002b:000000c420361810 EFLAGS: 00000202 ORIG_RAX: 0000000000000000 [ 44.650831][ T7292] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000047c530 [ 44.658786][ T7292] RDX: 0000000000001000 RSI: 000000c420330000 RDI: 0000000000000003 [ 44.666745][ T7292] RBP: 000000c420361868 R08: 0000000000000000 R09: 0000000000000000 [ 44.674699][ T7292] R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000010 [ 44.682652][ T7292] R13: ffffffffffffffff R14: 0000000000000004 R15: ffffffffffffffff [ 44.692234][ T7292] Kernel Offset: disabled [ 44.696555][ T7292] Rebooting in 86400 seconds..