[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 38.451716][ T25] audit: type=1800 audit(1572003348.753:25): pid=7036 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 38.495208][ T25] audit: type=1800 audit(1572003348.763:26): pid=7036 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 38.561312][ T25] audit: type=1800 audit(1572003348.763:27): pid=7036 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 '10.128.0.199' (ECDSA) to the list of known hosts. 2019/10/25 11:35:55 fuzzer started 2019/10/25 11:35:56 dialing manager at 10.128.0.105:33971 2019/10/25 11:35:56 syscalls: 2529 2019/10/25 11:35:56 code coverage: enabled 2019/10/25 11:35:56 comparison tracing: enabled 2019/10/25 11:35:56 extra coverage: extra coverage is not supported by the kernel 2019/10/25 11:35:56 setuid sandbox: enabled 2019/10/25 11:35:56 namespace sandbox: enabled 2019/10/25 11:35:56 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/25 11:35:56 fault injection: enabled 2019/10/25 11:35:56 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/25 11:35:56 net packet injection: enabled 2019/10/25 11:35:56 net device setup: enabled 2019/10/25 11:35:56 concurrency sanitizer: enabled 2019/10/25 11:35:57 adding functions to KCSAN blacklist: 'ext4_free_inodes_count' '__hrtimer_run_queues' 'generic_permission' 'find_next_bit' 'tomoyo_supervisor' 'run_timer_softirq' syzkaller login: [ 47.504372][ T7208] ================================================================== [ 47.512503][ T7208] BUG: KCSAN: data-race in __tcp_select_window / tcp_add_backlog [ 47.520224][ T7208] [ 47.522533][ T7208] write to 0xffff8881209c89ec of 4 bytes by interrupt on cpu 0: [ 47.530138][ T7208] tcp_add_backlog+0x4a0/0xcc0 [ 47.534879][ T7208] tcp_v4_rcv+0x1a60/0x1bb0 [ 47.539398][ T7208] ip_protocol_deliver_rcu+0x4d/0x420 [ 47.544790][ T7208] ip_local_deliver_finish+0x110/0x140 [ 47.550231][ T7208] ip_local_deliver+0x133/0x210 [ 47.555066][ T7208] ip_rcv_finish+0x121/0x160 [ 47.559639][ T7208] ip_rcv+0x18f/0x1a0 [ 47.563608][ T7208] __netif_receive_skb_one_core+0xa7/0xe0 [ 47.569310][ T7208] __netif_receive_skb+0x37/0xf0 [ 47.574226][ T7208] netif_receive_skb_internal+0x59/0x190 [ 47.579833][ T7208] napi_gro_receive+0x28f/0x330 [ 47.584670][ T7208] receive_buf+0x284/0x30b0 [ 47.589161][ T7208] virtnet_poll+0x436/0x7d0 [ 47.593641][ T7208] net_rx_action+0x3ae/0xa90 [ 47.598222][ T7208] [ 47.600533][ T7208] read to 0xffff8881209c89ec of 4 bytes by task 7208 on cpu 1: [ 47.608053][ T7208] __tcp_select_window+0x6b/0x4d0 [ 47.613056][ T7208] __tcp_ack_snd_check+0x117/0x4f0 [ 47.618145][ T7208] tcp_rcv_established+0xce9/0xf50 [ 47.623235][ T7208] tcp_v4_do_rcv+0x381/0x4e0 [ 47.627798][ T7208] __release_sock+0x135/0x1e0 [ 47.632449][ T7208] release_sock+0x61/0x160 [ 47.636856][ T7208] tcp_recvmsg+0x63b/0x1a30 [ 47.641346][ T7208] inet_recvmsg+0xbb/0x250 [ 47.645740][ T7208] sock_recvmsg+0x92/0xb0 [ 47.650043][ T7208] sock_read_iter+0x15f/0x1e0 [ 47.654698][ T7208] new_sync_read+0x389/0x4f0 [ 47.659273][ T7208] __vfs_read+0xb1/0xc0 [ 47.663415][ T7208] vfs_read+0x143/0x2c0 [ 47.667539][ T7208] [ 47.669841][ T7208] Reported by Kernel Concurrency Sanitizer on: [ 47.675980][ T7208] CPU: 1 PID: 7208 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 47.683416][ T7208] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 47.693446][ T7208] ================================================================== [ 47.701486][ T7208] Kernel panic - not syncing: panic_on_warn set ... [ 47.708058][ T7208] CPU: 1 PID: 7208 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 47.715487][ T7208] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 47.725516][ T7208] Call Trace: [ 47.728799][ T7208] dump_stack+0xf5/0x159 [ 47.733022][ T7208] panic+0x210/0x640 [ 47.736896][ T7208] ? sock_recvmsg+0x92/0xb0 [ 47.741375][ T7208] ? vprintk_func+0x8d/0x140 [ 47.745946][ T7208] kcsan_report.cold+0xc/0x10 [ 47.750602][ T7208] __kcsan_setup_watchpoint+0x32e/0x4a0 [ 47.756126][ T7208] __tsan_read4+0x2c/0x30 [ 47.760434][ T7208] __tcp_select_window+0x6b/0x4d0 [ 47.765441][ T7208] __tcp_ack_snd_check+0x117/0x4f0 [ 47.770533][ T7208] tcp_rcv_established+0xce9/0xf50 [ 47.775623][ T7208] ? ipv4_dst_check+0xc6/0xf0 [ 47.780278][ T7208] tcp_v4_do_rcv+0x381/0x4e0 [ 47.784857][ T7208] __release_sock+0x135/0x1e0 [ 47.789510][ T7208] release_sock+0x61/0x160 [ 47.793907][ T7208] tcp_recvmsg+0x63b/0x1a30 [ 47.798390][ T7208] ? __kcsan_setup_watchpoint+0x6b/0x4a0 [ 47.804009][ T7208] inet_recvmsg+0xbb/0x250 [ 47.808408][ T7208] ? __tsan_read8+0x2c/0x30 [ 47.812891][ T7208] ? inet_sendpage+0x100/0x100 [ 47.817637][ T7208] sock_recvmsg+0x92/0xb0 [ 47.821948][ T7208] sock_read_iter+0x15f/0x1e0 [ 47.826615][ T7208] new_sync_read+0x389/0x4f0 [ 47.831185][ T7208] __vfs_read+0xb1/0xc0 [ 47.835321][ T7208] vfs_read+0x143/0x2c0 [ 47.839455][ T7208] ksys_read+0xd5/0x1b0 [ 47.843593][ T7208] __x64_sys_read+0x4c/0x60 [ 47.848079][ T7208] do_syscall_64+0xcc/0x370 [ 47.852571][ T7208] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 47.858440][ T7208] RIP: 0033:0x47c530 [ 47.862332][ T7208] 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 [ 47.881923][ T7208] RSP: 002b:000000c4204df7d8 EFLAGS: 00000212 ORIG_RAX: 0000000000000000 [ 47.890319][ T7208] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000047c530 [ 47.898267][ T7208] RDX: 0000000000001000 RSI: 000000c42015e000 RDI: 0000000000000003 [ 47.906217][ T7208] RBP: 000000c4204df830 R08: 0000000000000000 R09: 0000000000000000 [ 47.914166][ T7208] R10: 0000000000000000 R11: 0000000000000212 R12: 0000000000000100 [ 47.922113][ T7208] R13: ffffffffffffffff R14: 0000000000000002 R15: ffffffffffffffff [ 47.931592][ T7208] Kernel Offset: disabled [ 47.935928][ T7208] Rebooting in 86400 seconds..