[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 34.488445][ T26] audit: type=1800 audit(1571784186.570:25): pid=7021 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 34.535499][ T26] audit: type=1800 audit(1571784186.570:26): pid=7021 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 34.571447][ T26] audit: type=1800 audit(1571784186.570:27): pid=7021 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 '10.128.0.67' (ECDSA) to the list of known hosts. 2019/10/22 22:43:13 fuzzer started 2019/10/22 22:43:15 dialing manager at 10.128.0.105:33369 2019/10/22 22:43:15 syscalls: 2524 2019/10/22 22:43:15 code coverage: enabled 2019/10/22 22:43:15 comparison tracing: enabled 2019/10/22 22:43:15 extra coverage: extra coverage is not supported by the kernel 2019/10/22 22:43:15 setuid sandbox: enabled 2019/10/22 22:43:15 namespace sandbox: enabled 2019/10/22 22:43:15 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/22 22:43:15 fault injection: enabled 2019/10/22 22:43:15 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/22 22:43:15 net packet injection: enabled 2019/10/22 22:43:15 net device setup: enabled 2019/10/22 22:43:15 concurrency sanitizer: enabled syzkaller login: [ 44.094079][ T7174] ================================================================== [ 44.102838][ T7174] BUG: KCSAN: data-race in tcp_add_backlog / tcp_grow_window.isra.0 [ 44.110818][ T7174] [ 44.113144][ T7174] write to 0xffff888124a1012c of 4 bytes by interrupt on cpu 0: [ 44.120772][ T7174] tcp_add_backlog+0x4a0/0xcc0 [ 44.125511][ T7174] tcp_v4_rcv+0x1a60/0x1bb0 [ 44.130016][ T7174] ip_protocol_deliver_rcu+0x4d/0x420 [ 44.135403][ T7174] ip_local_deliver_finish+0x110/0x140 [ 44.140843][ T7174] ip_local_deliver+0x133/0x210 [ 44.145682][ T7174] ip_rcv_finish+0x121/0x160 [ 44.150250][ T7174] ip_rcv+0x18f/0x1a0 [ 44.154209][ T7174] __netif_receive_skb_one_core+0xa7/0xe0 [ 44.159919][ T7174] __netif_receive_skb+0x37/0xf0 [ 44.164846][ T7174] netif_receive_skb_internal+0x59/0x190 [ 44.170452][ T7174] napi_gro_receive+0x28f/0x330 [ 44.175292][ T7174] receive_buf+0x284/0x30b0 [ 44.179769][ T7174] virtnet_poll+0x436/0x7d0 [ 44.184263][ T7174] net_rx_action+0x3ae/0xa90 [ 44.188820][ T7174] [ 44.191140][ T7174] read to 0xffff888124a1012c of 4 bytes by task 7174 on cpu 1: [ 44.198742][ T7174] tcp_grow_window.isra.0+0x6b/0x480 [ 44.204002][ T7174] tcp_event_data_recv+0x68f/0x990 [ 44.209087][ T7174] tcp_rcv_established+0xbfe/0xf50 [ 44.214186][ T7174] tcp_v4_do_rcv+0x381/0x4e0 [ 44.218767][ T7174] __release_sock+0x135/0x1e0 [ 44.223436][ T7174] release_sock+0x61/0x160 [ 44.227841][ T7174] tcp_recvmsg+0x63b/0x1a30 [ 44.232327][ T7174] inet_recvmsg+0xbb/0x250 [ 44.236819][ T7174] sock_recvmsg+0x92/0xb0 [ 44.241125][ T7174] sock_read_iter+0x15f/0x1e0 [ 44.245777][ T7174] new_sync_read+0x389/0x4f0 [ 44.250345][ T7174] __vfs_read+0xb1/0xc0 [ 44.254485][ T7174] vfs_read+0x143/0x2c0 [ 44.258618][ T7174] [ 44.260971][ T7174] Reported by Kernel Concurrency Sanitizer on: [ 44.267120][ T7174] CPU: 1 PID: 7174 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 44.274548][ T7174] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 44.284575][ T7174] ================================================================== [ 44.292622][ T7174] Kernel panic - not syncing: panic_on_warn set ... [ 44.299189][ T7174] CPU: 1 PID: 7174 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 44.306616][ T7174] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 44.316658][ T7174] Call Trace: [ 44.320029][ T7174] dump_stack+0xf5/0x159 [ 44.324252][ T7174] panic+0x210/0x640 [ 44.328127][ T7174] ? sock_recvmsg+0x92/0xb0 [ 44.332607][ T7174] ? vprintk_func+0x8d/0x140 [ 44.337189][ T7174] kcsan_report.cold+0xc/0x10 [ 44.341845][ T7174] __kcsan_setup_watchpoint+0x32e/0x4a0 [ 44.347377][ T7174] __tsan_read4+0x2c/0x30 [ 44.351686][ T7174] tcp_grow_window.isra.0+0x6b/0x480 [ 44.357194][ T7174] ? __kcsan_setup_watchpoint+0x6b/0x4a0 [ 44.362852][ T7174] tcp_event_data_recv+0x68f/0x990 [ 44.367963][ T7174] tcp_rcv_established+0xbfe/0xf50 [ 44.373074][ T7174] ? ipv4_dst_check+0xc6/0xf0 [ 44.377910][ T7174] tcp_v4_do_rcv+0x381/0x4e0 [ 44.382484][ T7174] __release_sock+0x135/0x1e0 [ 44.387144][ T7174] release_sock+0x61/0x160 [ 44.391567][ T7174] tcp_recvmsg+0x63b/0x1a30 [ 44.396068][ T7174] ? __kcsan_setup_watchpoint+0x6b/0x4a0 [ 44.401687][ T7174] inet_recvmsg+0xbb/0x250 [ 44.406083][ T7174] ? __tsan_read8+0x2c/0x30 [ 44.410581][ T7174] ? inet_sendpage+0x100/0x100 [ 44.415339][ T7174] sock_recvmsg+0x92/0xb0 [ 44.419650][ T7174] sock_read_iter+0x15f/0x1e0 [ 44.424323][ T7174] new_sync_read+0x389/0x4f0 [ 44.428896][ T7174] __vfs_read+0xb1/0xc0 [ 44.433031][ T7174] vfs_read+0x143/0x2c0 [ 44.437174][ T7174] ksys_read+0xd5/0x1b0 [ 44.441311][ T7174] __x64_sys_read+0x4c/0x60 [ 44.445795][ T7174] do_syscall_64+0xcc/0x370 [ 44.450302][ T7174] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 44.456172][ T7174] RIP: 0033:0x47c530 [ 44.460073][ T7174] 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 [ 44.479654][ T7174] RSP: 002b:000000c4203b9810 EFLAGS: 00000202 ORIG_RAX: 0000000000000000 [ 44.488046][ T7174] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000047c530 [ 44.495994][ T7174] RDX: 0000000000001000 RSI: 000000c4201a2000 RDI: 0000000000000003 [ 44.503953][ T7174] RBP: 000000c4203b9868 R08: 0000000000000000 R09: 0000000000000000 [ 44.511915][ T7174] R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000004 [ 44.519876][ T7174] R13: ffffffffffffffff R14: 0000000000000002 R15: ffffffffffffffff [ 44.529386][ T7174] Kernel Offset: disabled [ 44.533712][ T7174] Rebooting in 86400 seconds..