[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 33.562970][ T26] audit: type=1800 audit(1571298587.731:25): pid=7012 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 33.582765][ T26] audit: type=1800 audit(1571298587.731:26): pid=7012 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 33.602694][ T26] audit: type=1800 audit(1571298587.731:27): pid=7012 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 '10.128.1.52' (ECDSA) to the list of known hosts. 2019/10/17 07:49:56 fuzzer started 2019/10/17 07:49:57 dialing manager at 10.128.0.105:33899 2019/10/17 07:49:57 syscalls: 2524 2019/10/17 07:49:57 code coverage: enabled 2019/10/17 07:49:57 comparison tracing: enabled 2019/10/17 07:49:57 extra coverage: extra coverage is not supported by the kernel 2019/10/17 07:49:57 setuid sandbox: enabled 2019/10/17 07:49:57 namespace sandbox: enabled 2019/10/17 07:49:57 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/17 07:49:57 fault injection: enabled 2019/10/17 07:49:57 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/17 07:49:57 net packet injection: enabled 2019/10/17 07:49:57 net device setup: enabled 2019/10/17 07:49:57 concurrency sanitizer: enabled syzkaller login: [ 43.434676][ T7171] ================================================================== [ 43.442882][ T7171] BUG: KCSAN: data-race in tcp_add_backlog / tcp_rcv_space_adjust [ 43.450656][ T7171] [ 43.452970][ T7171] read to 0xffff88812559ea4c of 4 bytes by interrupt on cpu 0: [ 43.460489][ T7171] tcp_add_backlog+0x43/0xcc0 [ 43.465140][ T7171] tcp_v4_rcv+0x1a60/0x1bb0 [ 43.469639][ T7171] ip_protocol_deliver_rcu+0x4d/0x420 [ 43.475013][ T7171] ip_local_deliver_finish+0x110/0x140 [ 43.480444][ T7171] ip_local_deliver+0x133/0x210 [ 43.485270][ T7171] ip_rcv_finish+0x121/0x160 [ 43.489835][ T7171] ip_rcv+0x18f/0x1a0 [ 43.493793][ T7171] __netif_receive_skb_one_core+0xa7/0xe0 [ 43.499485][ T7171] __netif_receive_skb+0x37/0xf0 [ 43.504409][ T7171] netif_receive_skb_internal+0x59/0x190 [ 43.510034][ T7171] napi_gro_receive+0x28f/0x330 [ 43.514870][ T7171] receive_buf+0x284/0x30b0 [ 43.519358][ T7171] virtnet_poll+0x436/0x7d0 [ 43.523836][ T7171] net_rx_action+0x3ae/0xa90 [ 43.528393][ T7171] [ 43.530709][ T7171] write to 0xffff88812559ea4c of 4 bytes by task 7171 on cpu 1: [ 43.538322][ T7171] tcp_rcv_space_adjust+0x40f/0x4c0 [ 43.543494][ T7171] tcp_recvmsg+0xdaa/0x1a30 [ 43.548148][ T7171] inet_recvmsg+0xbb/0x250 [ 43.552563][ T7171] sock_recvmsg+0x92/0xb0 [ 43.556872][ T7171] sock_read_iter+0x15f/0x1e0 [ 43.561539][ T7171] new_sync_read+0x389/0x4f0 [ 43.566115][ T7171] __vfs_read+0xb1/0xc0 [ 43.570243][ T7171] vfs_read+0x143/0x2c0 [ 43.574386][ T7171] ksys_read+0xd5/0x1b0 [ 43.578526][ T7171] __x64_sys_read+0x4c/0x60 [ 43.583017][ T7171] do_syscall_64+0xcc/0x370 [ 43.587497][ T7171] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 43.593357][ T7171] [ 43.595659][ T7171] Reported by Kernel Concurrency Sanitizer on: [ 43.601789][ T7171] CPU: 1 PID: 7171 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 43.609213][ T7171] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 43.619240][ T7171] ================================================================== [ 43.627284][ T7171] Kernel panic - not syncing: panic_on_warn set ... [ 43.633853][ T7171] CPU: 1 PID: 7171 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 43.641280][ T7171] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 43.651322][ T7171] Call Trace: [ 43.654591][ T7171] dump_stack+0xf5/0x159 [ 43.658823][ T7171] panic+0x210/0x640 [ 43.662694][ T7171] ? ksys_read+0xd5/0x1b0 [ 43.667002][ T7171] ? vprintk_func+0x8d/0x140 [ 43.671594][ T7171] kcsan_report.cold+0xc/0x1b [ 43.676248][ T7171] __kcsan_setup_watchpoint+0x3ee/0x510 [ 43.681770][ T7171] __tsan_write4+0x32/0x40 [ 43.686164][ T7171] tcp_rcv_space_adjust+0x40f/0x4c0 [ 43.691343][ T7171] tcp_recvmsg+0xdaa/0x1a30 [ 43.695824][ T7171] ? __kcsan_setup_watchpoint+0x96/0x510 [ 43.701431][ T7171] inet_recvmsg+0xbb/0x250 [ 43.705824][ T7171] ? __tsan_read8+0x2c/0x30 [ 43.710315][ T7171] ? inet_sendpage+0x100/0x100 [ 43.715056][ T7171] sock_recvmsg+0x92/0xb0 [ 43.719364][ T7171] sock_read_iter+0x15f/0x1e0 [ 43.724022][ T7171] new_sync_read+0x389/0x4f0 [ 43.728593][ T7171] __vfs_read+0xb1/0xc0 [ 43.732726][ T7171] vfs_read+0x143/0x2c0 [ 43.736869][ T7171] ksys_read+0xd5/0x1b0 [ 43.741106][ T7171] __x64_sys_read+0x4c/0x60 [ 43.745591][ T7171] do_syscall_64+0xcc/0x370 [ 43.750072][ T7171] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 43.755948][ T7171] RIP: 0033:0x47c530 [ 43.760003][ T7171] 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 [ 43.779598][ T7171] RSP: 002b:000000c42014d7d8 EFLAGS: 00000212 ORIG_RAX: 0000000000000000 [ 43.788001][ T7171] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000047c530 [ 43.795970][ T7171] RDX: 0000000000001000 RSI: 000000c42015c000 RDI: 0000000000000003 [ 43.803924][ T7171] RBP: 000000c42014d830 R08: 0000000000000000 R09: 0000000000000000 [ 43.811885][ T7171] R10: 0000000000000000 R11: 0000000000000212 R12: 0000000000000200 [ 43.819845][ T7171] R13: ffffffffffffffff R14: 0000000000000002 R15: ffffffffffffffff [ 43.829142][ T7171] Kernel Offset: disabled [ 43.833462][ T7171] Rebooting in 86400 seconds..