[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 37.873774][ T26] audit: type=1800 audit(1571771675.655:25): pid=7061 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 37.901128][ T26] audit: type=1800 audit(1571771675.655:26): pid=7061 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 37.927846][ T26] audit: type=1800 audit(1571771675.655:27): pid=7061 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 '10.128.1.28' (ECDSA) to the list of known hosts. 2019/10/22 19:14:44 fuzzer started 2019/10/22 19:14:45 dialing manager at 10.128.0.105:33369 2019/10/22 19:14:45 syscalls: 2524 2019/10/22 19:14:45 code coverage: enabled 2019/10/22 19:14:45 comparison tracing: enabled 2019/10/22 19:14:45 extra coverage: extra coverage is not supported by the kernel 2019/10/22 19:14:45 setuid sandbox: enabled 2019/10/22 19:14:45 namespace sandbox: enabled 2019/10/22 19:14:45 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/22 19:14:45 fault injection: enabled 2019/10/22 19:14:45 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/22 19:14:45 net packet injection: enabled 2019/10/22 19:14:45 net device setup: enabled 2019/10/22 19:14:45 concurrency sanitizer: enabled syzkaller login: [ 48.736577][ T7213] ================================================================== [ 48.744713][ T7213] BUG: KCSAN: data-race in tcp_add_backlog / tcp_grow_window.isra.0 [ 48.752677][ T7213] [ 48.755013][ T7213] write to 0xffff888128c5412c of 4 bytes by interrupt on cpu 0: [ 48.762667][ T7213] tcp_add_backlog+0x4a0/0xcc0 [ 48.767441][ T7213] tcp_v4_rcv+0x1a60/0x1bb0 [ 48.771919][ T7213] ip_protocol_deliver_rcu+0x4d/0x420 [ 48.777265][ T7213] ip_local_deliver_finish+0x110/0x140 [ 48.782701][ T7213] ip_local_deliver+0x133/0x210 [ 48.787534][ T7213] ip_rcv_finish+0x121/0x160 [ 48.792107][ T7213] ip_rcv+0x18f/0x1a0 [ 48.796064][ T7213] __netif_receive_skb_one_core+0xa7/0xe0 [ 48.801754][ T7213] __netif_receive_skb+0x37/0xf0 [ 48.806664][ T7213] netif_receive_skb_internal+0x59/0x190 [ 48.812270][ T7213] napi_gro_receive+0x28f/0x330 [ 48.817095][ T7213] receive_buf+0x284/0x30b0 [ 48.821573][ T7213] virtnet_poll+0x436/0x7d0 [ 48.826048][ T7213] net_rx_action+0x3ae/0xa90 [ 48.830604][ T7213] [ 48.832912][ T7213] read to 0xffff888128c5412c of 4 bytes by task 7213 on cpu 1: [ 48.840436][ T7213] tcp_grow_window.isra.0+0x6b/0x480 [ 48.845700][ T7213] tcp_event_data_recv+0x68f/0x990 [ 48.850785][ T7213] tcp_rcv_established+0xbfe/0xf50 [ 48.855875][ T7213] tcp_v4_do_rcv+0x381/0x4e0 [ 48.860438][ T7213] __release_sock+0x135/0x1e0 [ 48.865176][ T7213] release_sock+0x61/0x160 [ 48.869583][ T7213] tcp_recvmsg+0x63b/0x1a30 [ 48.874060][ T7213] inet_recvmsg+0xbb/0x250 [ 48.878452][ T7213] sock_recvmsg+0x92/0xb0 [ 48.882754][ T7213] sock_read_iter+0x15f/0x1e0 [ 48.887406][ T7213] new_sync_read+0x389/0x4f0 [ 48.891972][ T7213] __vfs_read+0xb1/0xc0 [ 48.896099][ T7213] vfs_read+0x143/0x2c0 [ 48.900221][ T7213] [ 48.902530][ T7213] Reported by Kernel Concurrency Sanitizer on: [ 48.908664][ T7213] CPU: 1 PID: 7213 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 48.919227][ T7213] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 48.929265][ T7213] ================================================================== [ 48.937309][ T7213] Kernel panic - not syncing: panic_on_warn set ... [ 48.943875][ T7213] CPU: 1 PID: 7213 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 48.951312][ T7213] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 48.961351][ T7213] Call Trace: [ 48.964621][ T7213] dump_stack+0xf5/0x159 [ 48.968843][ T7213] panic+0x210/0x640 [ 48.972719][ T7213] ? sock_recvmsg+0x92/0xb0 [ 48.977195][ T7213] ? vprintk_func+0x8d/0x140 [ 48.981764][ T7213] kcsan_report.cold+0xc/0x10 [ 48.986424][ T7213] __kcsan_setup_watchpoint+0x32e/0x4a0 [ 48.991945][ T7213] __tsan_read4+0x2c/0x30 [ 48.996261][ T7213] tcp_grow_window.isra.0+0x6b/0x480 [ 49.001532][ T7213] ? __kcsan_setup_watchpoint+0x6b/0x4a0 [ 49.007149][ T7213] tcp_event_data_recv+0x68f/0x990 [ 49.012241][ T7213] tcp_rcv_established+0xbfe/0xf50 [ 49.017331][ T7213] ? ipv4_dst_check+0xc6/0xf0 [ 49.021983][ T7213] tcp_v4_do_rcv+0x381/0x4e0 [ 49.026564][ T7213] __release_sock+0x135/0x1e0 [ 49.031577][ T7213] release_sock+0x61/0x160 [ 49.035974][ T7213] tcp_recvmsg+0x63b/0x1a30 [ 49.040460][ T7213] inet_recvmsg+0xbb/0x250 [ 49.044851][ T7213] ? __tsan_read8+0x2c/0x30 [ 49.049333][ T7213] ? inet_sendpage+0x100/0x100 [ 49.054073][ T7213] sock_recvmsg+0x92/0xb0 [ 49.058381][ T7213] sock_read_iter+0x15f/0x1e0 [ 49.063036][ T7213] new_sync_read+0x389/0x4f0 [ 49.067616][ T7213] __vfs_read+0xb1/0xc0 [ 49.071759][ T7213] vfs_read+0x143/0x2c0 [ 49.075894][ T7213] ksys_read+0xd5/0x1b0 [ 49.080031][ T7213] __x64_sys_read+0x4c/0x60 [ 49.084514][ T7213] do_syscall_64+0xcc/0x370 [ 49.088995][ T7213] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 49.094861][ T7213] RIP: 0033:0x47c530 [ 49.098735][ T7213] 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 [ 49.118325][ T7213] RSP: 002b:000000c4201497d8 EFLAGS: 00000212 ORIG_RAX: 0000000000000000 [ 49.126725][ T7213] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000047c530 [ 49.134682][ T7213] RDX: 0000000000001000 RSI: 000000c42031a000 RDI: 0000000000000003 [ 49.142627][ T7213] RBP: 000000c420149830 R08: 0000000000000000 R09: 0000000000000000 [ 49.150572][ T7213] R10: 0000000000000000 R11: 0000000000000212 R12: 0000000000000008 [ 49.158520][ T7213] R13: ffffffffffffffff R14: 0000000000000010 R15: ffffffffffffffff [ 49.167836][ T7213] Kernel Offset: disabled [ 49.172165][ T7213] Rebooting in 86400 seconds..