[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 36.158753][ T26] audit: type=1800 audit(1571787288.423:25): pid=7026 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 36.202338][ T26] audit: type=1800 audit(1571787288.433:26): pid=7026 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 36.224817][ T26] audit: type=1800 audit(1571787288.433:27): pid=7026 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 '10.128.0.167' (ECDSA) to the list of known hosts. 2019/10/22 23:35:00 fuzzer started 2019/10/22 23:35:02 dialing manager at 10.128.0.105:33369 2019/10/22 23:35:02 syscalls: 2524 2019/10/22 23:35:02 code coverage: enabled 2019/10/22 23:35:02 comparison tracing: enabled 2019/10/22 23:35:02 extra coverage: extra coverage is not supported by the kernel 2019/10/22 23:35:02 setuid sandbox: enabled 2019/10/22 23:35:02 namespace sandbox: enabled 2019/10/22 23:35:02 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/22 23:35:02 fault injection: enabled 2019/10/22 23:35:02 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/22 23:35:02 net packet injection: enabled 2019/10/22 23:35:02 net device setup: enabled 2019/10/22 23:35:02 concurrency sanitizer: enabled syzkaller login: [ 50.217986][ T7195] ================================================================== [ 50.226134][ T7195] BUG: KCSAN: data-race in tcp_add_backlog / tcp_grow_window.isra.0 [ 50.234095][ T7195] [ 50.236438][ T7195] write to 0xffff8881218a212c of 4 bytes by interrupt on cpu 0: [ 50.244056][ T7195] tcp_add_backlog+0x4a0/0xcc0 [ 50.249175][ T7195] tcp_v4_rcv+0x1a60/0x1bb0 [ 50.253831][ T7195] ip_protocol_deliver_rcu+0x4d/0x420 [ 50.259201][ T7195] ip_local_deliver_finish+0x110/0x140 [ 50.264643][ T7195] ip_local_deliver+0x133/0x210 [ 50.269602][ T7195] ip_rcv_finish+0x121/0x160 [ 50.274214][ T7195] ip_rcv+0x18f/0x1a0 [ 50.278187][ T7195] __netif_receive_skb_one_core+0xa7/0xe0 [ 50.283974][ T7195] __netif_receive_skb+0x37/0xf0 [ 50.288901][ T7195] netif_receive_skb_internal+0x59/0x190 [ 50.294517][ T7195] napi_gro_receive+0x28f/0x330 [ 50.299342][ T7195] receive_buf+0x284/0x30b0 [ 50.304426][ T7195] virtnet_poll+0x436/0x7d0 [ 50.308906][ T7195] net_rx_action+0x3ae/0xa90 [ 50.313474][ T7195] [ 50.315796][ T7195] read to 0xffff8881218a212c of 4 bytes by task 7195 on cpu 1: [ 50.323318][ T7195] tcp_grow_window.isra.0+0x6b/0x480 [ 50.328589][ T7195] tcp_event_data_recv+0x68f/0x990 [ 50.333677][ T7195] tcp_rcv_established+0xbfe/0xf50 [ 50.338782][ T7195] tcp_v4_do_rcv+0x381/0x4e0 [ 50.343348][ T7195] __release_sock+0x135/0x1e0 [ 50.348004][ T7195] release_sock+0x61/0x160 [ 50.352413][ T7195] tcp_recvmsg+0x63b/0x1a30 [ 50.356982][ T7195] inet_recvmsg+0xbb/0x250 [ 50.361373][ T7195] sock_recvmsg+0x92/0xb0 [ 50.365683][ T7195] sock_read_iter+0x15f/0x1e0 [ 50.370332][ T7195] new_sync_read+0x389/0x4f0 [ 50.374906][ T7195] __vfs_read+0xb1/0xc0 [ 50.379036][ T7195] vfs_read+0x143/0x2c0 [ 50.383172][ T7195] [ 50.385471][ T7195] Reported by Kernel Concurrency Sanitizer on: [ 50.391606][ T7195] CPU: 1 PID: 7195 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 50.399033][ T7195] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 50.409076][ T7195] ================================================================== [ 50.417123][ T7195] Kernel panic - not syncing: panic_on_warn set ... [ 50.423689][ T7195] CPU: 1 PID: 7195 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 50.431120][ T7195] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 50.441235][ T7195] Call Trace: [ 50.444510][ T7195] dump_stack+0xf5/0x159 [ 50.448742][ T7195] panic+0x210/0x640 [ 50.452622][ T7195] ? sock_recvmsg+0x92/0xb0 [ 50.457122][ T7195] ? vprintk_func+0x8d/0x140 [ 50.461714][ T7195] kcsan_report.cold+0xc/0x10 [ 50.466805][ T7195] __kcsan_setup_watchpoint+0x32e/0x4a0 [ 50.472340][ T7195] __tsan_read4+0x2c/0x30 [ 50.476653][ T7195] tcp_grow_window.isra.0+0x6b/0x480 [ 50.481998][ T7195] ? __kcsan_setup_watchpoint+0x6b/0x4a0 [ 50.487608][ T7195] tcp_event_data_recv+0x68f/0x990 [ 50.492698][ T7195] tcp_rcv_established+0xbfe/0xf50 [ 50.497788][ T7195] ? ipv4_dst_check+0xc6/0xf0 [ 50.502443][ T7195] tcp_v4_do_rcv+0x381/0x4e0 [ 50.507021][ T7195] __release_sock+0x135/0x1e0 [ 50.511676][ T7195] release_sock+0x61/0x160 [ 50.516079][ T7195] tcp_recvmsg+0x63b/0x1a30 [ 50.520595][ T7195] inet_recvmsg+0xbb/0x250 [ 50.524987][ T7195] ? __tsan_read8+0x2c/0x30 [ 50.529471][ T7195] ? inet_sendpage+0x100/0x100 [ 50.534214][ T7195] sock_recvmsg+0x92/0xb0 [ 50.538520][ T7195] sock_read_iter+0x15f/0x1e0 [ 50.543181][ T7195] new_sync_read+0x389/0x4f0 [ 50.547765][ T7195] __vfs_read+0xb1/0xc0 [ 50.551909][ T7195] vfs_read+0x143/0x2c0 [ 50.556050][ T7195] ksys_read+0xd5/0x1b0 [ 50.560197][ T7195] __x64_sys_read+0x4c/0x60 [ 50.564691][ T7195] do_syscall_64+0xcc/0x370 [ 50.569193][ T7195] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 50.575092][ T7195] RIP: 0033:0x47c530 [ 50.578970][ T7195] 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 [ 50.598564][ T7195] RSP: 002b:000000c420343810 EFLAGS: 00000202 ORIG_RAX: 0000000000000000 [ 50.607063][ T7195] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000047c530 [ 50.615034][ T7195] RDX: 0000000000001000 RSI: 000000c4202c2000 RDI: 0000000000000003 [ 50.622995][ T7195] RBP: 000000c420343868 R08: 0000000000000000 R09: 0000000000000000 [ 50.630946][ T7195] R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000008 [ 50.638895][ T7195] R13: ffffffffffffffff R14: 0000000000000002 R15: ffffffffffffffff [ 50.648446][ T7195] Kernel Offset: disabled [ 50.652820][ T7195] Rebooting in 86400 seconds..