[ 41.943057][ T25] audit: type=1800 audit(1571886952.561:24): pid=7142 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="sudo" dev="sda1" ino=2487 res=0 [....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 42.484107][ T25] audit: type=1800 audit(1571886953.181:25): pid=7142 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 42.521300][ T25] audit: type=1800 audit(1571886953.181:26): pid=7142 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 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 '10.128.0.23' (ECDSA) to the list of known hosts. 2019/10/24 03:16:05 fuzzer started 2019/10/24 03:16:07 dialing manager at 10.128.0.105:40369 2019/10/24 03:16:07 syscalls: 2524 2019/10/24 03:16:07 code coverage: enabled 2019/10/24 03:16:07 comparison tracing: enabled syzkaller login: [ 56.941738][ T7291] ================================================================== [ 56.952693][ T7291] BUG: KCSAN: data-race in __tcp_select_window / tcp_add_backlog [ 56.961676][ T7291] [ 56.964979][ T7291] write to 0xffff88811fdc816c of 4 bytes by interrupt on cpu 1: [ 56.973965][ T7291] tcp_add_backlog+0x4a0/0xcc0 [ 56.981762][ T7291] tcp_v4_rcv+0x1a60/0x1bb0 [ 56.986563][ T7291] ip_protocol_deliver_rcu+0x4d/0x420 [ 56.992919][ T7291] ip_local_deliver_finish+0x110/0x140 [ 56.998663][ T7291] ip_local_deliver+0x133/0x210 [ 57.005088][ T7291] ip_rcv_finish+0x121/0x160 [ 57.010490][ T7291] ip_rcv+0x18f/0x1a0 [ 57.014825][ T7291] __netif_receive_skb_one_core+0xa7/0xe0 [ 57.020907][ T7291] __netif_receive_skb+0x37/0xf0 [ 57.026766][ T7291] netif_receive_skb_internal+0x59/0x190 [ 57.032674][ T7291] napi_gro_receive+0x28f/0x330 [ 57.038324][ T7291] receive_buf+0x284/0x30b0 [ 57.043110][ T7291] virtnet_poll+0x436/0x7d0 [ 57.048071][ T7291] net_rx_action+0x3ae/0xa90 [ 57.052847][ T7291] [ 57.055378][ T7291] read to 0xffff88811fdc816c of 4 bytes by task 7291 on cpu 0: [ 57.063399][ T7291] __tcp_select_window+0x6b/0x4d0 [ 57.068912][ T7291] __tcp_transmit_skb+0x700/0x1d60 [ 57.074413][ T7291] tcp_write_xmit+0x9f3/0x3080 [ 57.079561][ T7291] __tcp_push_pending_frames+0x7b/0x1d0 [ 57.085614][ T7291] tcp_push+0x1e9/0x3d0 [ 57.090036][ T7291] tcp_sendmsg_locked+0x1d1e/0x1f30 [ 57.095909][ T7291] tcp_sendmsg+0x39/0x60 [ 57.100652][ T7291] inet_sendmsg+0x6d/0x90 [ 57.106092][ T7291] sock_sendmsg+0x9f/0xc0 [ 57.111563][ T7291] sock_write_iter+0x16b/0x210 [ 57.116354][ T7291] new_sync_write+0x388/0x4a0 [ 57.121896][ T7291] __vfs_write+0xb1/0xc0 [ 57.129413][ T7291] vfs_write+0x18a/0x390 [ 57.134190][ T7291] [ 57.137129][ T7291] Reported by Kernel Concurrency Sanitizer on: [ 57.143561][ T7291] CPU: 0 PID: 7291 Comm: sshd Not tainted 5.4.0-rc3+ #0 [ 57.152082][ T7291] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 57.163335][ T7291] ================================================================== [ 57.173240][ T7291] Kernel panic - not syncing: panic_on_warn set ... [ 57.180802][ T7291] CPU: 0 PID: 7291 Comm: sshd Not tainted 5.4.0-rc3+ #0 [ 57.198924][ T7291] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 57.209619][ T7291] Call Trace: [ 57.213094][ T7291] dump_stack+0xf5/0x159 [ 57.217645][ T7291] panic+0x210/0x640 [ 57.221639][ T7291] ? sock_sendmsg+0x9f/0xc0 [ 57.226427][ T7291] ? vprintk_func+0x8d/0x140 [ 57.231728][ T7291] kcsan_report.cold+0xc/0x10 [ 57.236973][ T7291] __kcsan_setup_watchpoint+0x32e/0x4a0 [ 57.243348][ T7291] __tsan_read4+0x2c/0x30 [ 57.248252][ T7291] __tcp_select_window+0x6b/0x4d0 [ 57.253557][ T7291] __tcp_transmit_skb+0x700/0x1d60 [ 57.258885][ T7291] tcp_write_xmit+0x9f3/0x3080 [ 57.264259][ T7291] ? kmem_cache_alloc_node_trace+0x273/0x670 [ 57.271012][ T7291] __tcp_push_pending_frames+0x7b/0x1d0 [ 57.277268][ T7291] tcp_push+0x1e9/0x3d0 [ 57.282150][ T7291] tcp_sendmsg_locked+0x1d1e/0x1f30 [ 57.291953][ T7291] tcp_sendmsg+0x39/0x60 [ 57.299534][ T7291] inet_sendmsg+0x6d/0x90 [ 57.304129][ T7291] ? inet_send_prepare+0x200/0x200 [ 57.309692][ T7291] sock_sendmsg+0x9f/0xc0 [ 57.314613][ T7291] sock_write_iter+0x16b/0x210 [ 57.319793][ T7291] new_sync_write+0x388/0x4a0 [ 57.325376][ T7291] __vfs_write+0xb1/0xc0 [ 57.329816][ T7291] vfs_write+0x18a/0x390 [ 57.334252][ T7291] ksys_write+0xd5/0x1b0 [ 57.338941][ T7291] __x64_sys_write+0x4c/0x60 [ 57.343780][ T7291] do_syscall_64+0xcc/0x370 [ 57.348902][ T7291] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 57.355377][ T7291] RIP: 0033:0x7fac7356d370 [ 57.360269][ T7291] Code: 73 01 c3 48 8b 0d c8 4a 2b 00 31 d2 48 29 c2 64 89 11 48 83 c8 ff eb ea 90 90 83 3d 85 a2 2b 00 00 75 10 b8 01 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 0e 8a 01 00 48 89 04 24 [ 57.382286][ T7291] RSP: 002b:00007fff110b0a58 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 [ 57.391501][ T7291] RAX: ffffffffffffffda RBX: 00000000000001f8 RCX: 00007fac7356d370 [ 57.400224][ T7291] RDX: 00000000000001f8 RSI: 00005570f7f9b460 RDI: 0000000000000003 [ 57.408770][ T7291] RBP: 00005570f7f9b460 R08: 0000000000000001 R09: 0101010101010101 [ 57.418025][ T7291] R10: 0000000000000008 R11: 0000000000000246 R12: 00007fff110b0abc [ 57.427488][ T7291] R13: 00005570f7e13fb4 R14: 0000000000000028 R15: 00005570f7e15ca0 [ 57.703626][ T7291] Kernel Offset: disabled [ 57.708772][ T7291] Rebooting in 86400 seconds..