[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 34.848263][ T26] audit: type=1800 audit(1571746045.675:25): pid=7097 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 34.894153][ T26] audit: type=1800 audit(1571746045.675:26): pid=7097 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 34.935764][ T26] audit: type=1800 audit(1571746045.675:27): pid=7097 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 '10.128.0.147' (ECDSA) to the list of known hosts. 2019/10/22 12:07:32 fuzzer started 2019/10/22 12:07:33 dialing manager at 10.128.0.105:37053 2019/10/22 12:07:33 syscalls: 2524 2019/10/22 12:07:33 code coverage: enabled 2019/10/22 12:07:33 comparison tracing: enabled 2019/10/22 12:07:33 extra coverage: extra coverage is not supported by the kernel 2019/10/22 12:07:33 setuid sandbox: enabled 2019/10/22 12:07:33 namespace sandbox: enabled 2019/10/22 12:07:33 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/22 12:07:33 fault injection: enabled 2019/10/22 12:07:33 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/22 12:07:33 net packet injection: enabled 2019/10/22 12:07:33 net device setup: enabled 2019/10/22 12:07:33 concurrency sanitizer: enabled syzkaller login: [ 44.257297][ T7249] ================================================================== [ 44.265457][ T7249] BUG: KCSAN: data-race in tcp_add_backlog / tcp_grow_window.isra.0 [ 44.273421][ T7249] [ 44.275754][ T7249] write to 0xffff8881265ae9ec of 4 bytes by interrupt on cpu 1: [ 44.283487][ T7249] tcp_add_backlog+0x4a0/0xcc0 [ 44.288230][ T7249] tcp_v4_rcv+0x1a60/0x1bb0 [ 44.292731][ T7249] ip_protocol_deliver_rcu+0x4d/0x420 [ 44.298121][ T7249] ip_local_deliver_finish+0x110/0x140 [ 44.303557][ T7249] ip_local_deliver+0x133/0x210 [ 44.308420][ T7249] ip_rcv_finish+0x121/0x160 [ 44.313007][ T7249] ip_rcv+0x18f/0x1a0 [ 44.317057][ T7249] __netif_receive_skb_one_core+0xa7/0xe0 [ 44.322780][ T7249] __netif_receive_skb+0x37/0xf0 [ 44.327841][ T7249] netif_receive_skb_internal+0x59/0x190 [ 44.333478][ T7249] napi_gro_receive+0x28f/0x330 [ 44.338320][ T7249] receive_buf+0x284/0x30b0 [ 44.342922][ T7249] virtnet_poll+0x436/0x7d0 [ 44.347419][ T7249] net_rx_action+0x3ae/0xa90 [ 44.351983][ T7249] [ 44.354295][ T7249] read to 0xffff8881265ae9ec of 4 bytes by task 7249 on cpu 0: [ 44.361818][ T7249] tcp_grow_window.isra.0+0x6b/0x480 [ 44.367078][ T7249] tcp_event_data_recv+0x68f/0x990 [ 44.372395][ T7249] tcp_rcv_established+0xbfe/0xf50 [ 44.377495][ T7249] tcp_v4_do_rcv+0x381/0x4e0 [ 44.382094][ T7249] __release_sock+0x135/0x1e0 [ 44.386755][ T7249] release_sock+0x61/0x160 [ 44.391170][ T7249] tcp_recvmsg+0x63b/0x1a30 [ 44.395663][ T7249] inet_recvmsg+0xbb/0x250 [ 44.400060][ T7249] sock_recvmsg+0x92/0xb0 [ 44.404367][ T7249] sock_read_iter+0x15f/0x1e0 [ 44.409044][ T7249] new_sync_read+0x389/0x4f0 [ 44.413626][ T7249] __vfs_read+0xb1/0xc0 [ 44.417758][ T7249] vfs_read+0x143/0x2c0 [ 44.421883][ T7249] [ 44.424218][ T7249] Reported by Kernel Concurrency Sanitizer on: [ 44.430350][ T7249] CPU: 0 PID: 7249 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 44.437779][ T7249] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 44.447828][ T7249] ================================================================== [ 44.455895][ T7249] Kernel panic - not syncing: panic_on_warn set ... [ 44.462481][ T7249] CPU: 0 PID: 7249 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 44.469948][ T7249] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 44.479987][ T7249] Call Trace: [ 44.483268][ T7249] dump_stack+0xf5/0x159 [ 44.487501][ T7249] panic+0x210/0x640 [ 44.491383][ T7249] ? sock_recvmsg+0x92/0xb0 [ 44.495879][ T7249] ? vprintk_func+0x8d/0x140 [ 44.500450][ T7249] kcsan_report.cold+0xc/0x10 [ 44.505109][ T7249] __kcsan_setup_watchpoint+0x32e/0x4a0 [ 44.510650][ T7249] __tsan_read4+0x2c/0x30 [ 44.514959][ T7249] tcp_grow_window.isra.0+0x6b/0x480 [ 44.520219][ T7249] ? __kcsan_setup_watchpoint+0x6b/0x4a0 [ 44.525833][ T7249] tcp_event_data_recv+0x68f/0x990 [ 44.530940][ T7249] tcp_rcv_established+0xbfe/0xf50 [ 44.536143][ T7249] ? ipv4_dst_check+0xc6/0xf0 [ 44.540949][ T7249] tcp_v4_do_rcv+0x381/0x4e0 [ 44.545555][ T7249] __release_sock+0x135/0x1e0 [ 44.550275][ T7249] release_sock+0x61/0x160 [ 44.554738][ T7249] tcp_recvmsg+0x63b/0x1a30 [ 44.559229][ T7249] inet_recvmsg+0xbb/0x250 [ 44.563631][ T7249] ? __tsan_read8+0x2c/0x30 [ 44.568130][ T7249] ? inet_sendpage+0x100/0x100 [ 44.572876][ T7249] sock_recvmsg+0x92/0xb0 [ 44.577194][ T7249] sock_read_iter+0x15f/0x1e0 [ 44.581871][ T7249] new_sync_read+0x389/0x4f0 [ 44.586448][ T7249] __vfs_read+0xb1/0xc0 [ 44.590592][ T7249] vfs_read+0x143/0x2c0 [ 44.594726][ T7249] ksys_read+0xd5/0x1b0 [ 44.598878][ T7249] __x64_sys_read+0x4c/0x60 [ 44.603362][ T7249] do_syscall_64+0xcc/0x370 [ 44.607859][ T7249] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 44.613731][ T7249] RIP: 0033:0x47c530 [ 44.617608][ T7249] 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 [ 44.637205][ T7249] RSP: 002b:000000c4203417d8 EFLAGS: 00000212 ORIG_RAX: 0000000000000000 [ 44.645607][ T7249] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000047c530 [ 44.653558][ T7249] RDX: 0000000000001000 RSI: 000000c4202bc000 RDI: 0000000000000003 [ 44.661508][ T7249] RBP: 000000c420341830 R08: 0000000000000000 R09: 0000000000000000 [ 44.669456][ T7249] R10: 0000000000000000 R11: 0000000000000212 R12: 0000000000000004 [ 44.677407][ T7249] R13: ffffffffffffffff R14: 0000000000000020 R15: ffffffffffffffff [ 44.686721][ T7249] Kernel Offset: disabled [ 44.691157][ T7249] Rebooting in 86400 seconds..