[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 39.040220][ T26] audit: type=1800 audit(1571762505.060:25): pid=7118 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 39.067206][ T26] audit: type=1800 audit(1571762505.060:26): pid=7118 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 39.087411][ T26] audit: type=1800 audit(1571762505.060:27): pid=7118 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 '10.128.1.0' (ECDSA) to the list of known hosts. 2019/10/22 16:41:55 fuzzer started 2019/10/22 16:41:57 dialing manager at 10.128.0.105:33369 2019/10/22 16:41:57 syscalls: 2524 2019/10/22 16:41:57 code coverage: enabled 2019/10/22 16:41:57 comparison tracing: enabled 2019/10/22 16:41:57 extra coverage: extra coverage is not supported by the kernel 2019/10/22 16:41:57 setuid sandbox: enabled 2019/10/22 16:41:57 namespace sandbox: enabled 2019/10/22 16:41:57 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/22 16:41:57 fault injection: enabled 2019/10/22 16:41:57 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/22 16:41:57 net packet injection: enabled 2019/10/22 16:41:57 net device setup: enabled 2019/10/22 16:41:57 concurrency sanitizer: enabled syzkaller login: [ 51.506581][ T7279] ================================================================== [ 51.514742][ T7279] BUG: KCSAN: data-race in __tcp_select_window / tcp_add_backlog [ 51.522438][ T7279] [ 51.524746][ T7279] write to 0xffff8881211f12ec of 4 bytes by interrupt on cpu 1: [ 51.532352][ T7279] tcp_add_backlog+0x4a0/0xcc0 [ 51.537093][ T7279] tcp_v4_rcv+0x1a60/0x1bb0 [ 51.541571][ T7279] ip_protocol_deliver_rcu+0x4d/0x420 [ 51.546937][ T7279] ip_local_deliver_finish+0x110/0x140 [ 51.552381][ T7279] ip_local_deliver+0x133/0x210 [ 51.557203][ T7279] ip_rcv_finish+0x121/0x160 [ 51.561764][ T7279] ip_rcv+0x18f/0x1a0 [ 51.565722][ T7279] __netif_receive_skb_one_core+0xa7/0xe0 [ 51.571455][ T7279] __netif_receive_skb+0x37/0xf0 [ 51.576369][ T7279] netif_receive_skb_internal+0x59/0x190 [ 51.581974][ T7279] napi_gro_receive+0x28f/0x330 [ 51.586840][ T7279] receive_buf+0x284/0x30b0 [ 51.591329][ T7279] virtnet_poll+0x436/0x7d0 [ 51.595815][ T7279] net_rx_action+0x3ae/0xa90 [ 51.600389][ T7279] [ 51.602706][ T7279] read to 0xffff8881211f12ec of 4 bytes by task 7279 on cpu 0: [ 51.610224][ T7279] __tcp_select_window+0x6b/0x4d0 [ 51.615226][ T7279] __tcp_ack_snd_check+0x117/0x4f0 [ 51.620325][ T7279] tcp_rcv_established+0xce9/0xf50 [ 51.625422][ T7279] tcp_v4_do_rcv+0x381/0x4e0 [ 51.629998][ T7279] __release_sock+0x135/0x1e0 [ 51.634650][ T7279] release_sock+0x61/0x160 [ 51.639043][ T7279] tcp_recvmsg+0x63b/0x1a30 [ 51.643521][ T7279] inet_recvmsg+0xbb/0x250 [ 51.647913][ T7279] sock_recvmsg+0x92/0xb0 [ 51.652229][ T7279] sock_read_iter+0x15f/0x1e0 [ 51.656897][ T7279] new_sync_read+0x389/0x4f0 [ 51.661459][ T7279] __vfs_read+0xb1/0xc0 [ 51.665589][ T7279] vfs_read+0x143/0x2c0 [ 51.669722][ T7279] [ 51.672033][ T7279] Reported by Kernel Concurrency Sanitizer on: [ 51.678162][ T7279] CPU: 0 PID: 7279 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 51.685589][ T7279] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 51.695637][ T7279] ================================================================== [ 51.703673][ T7279] Kernel panic - not syncing: panic_on_warn set ... [ 51.710245][ T7279] CPU: 0 PID: 7279 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 51.717681][ T7279] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 51.727708][ T7279] Call Trace: [ 51.730977][ T7279] dump_stack+0xf5/0x159 [ 51.735194][ T7279] panic+0x210/0x640 [ 51.739066][ T7279] ? sock_recvmsg+0x92/0xb0 [ 51.743548][ T7279] ? vprintk_func+0x8d/0x140 [ 51.748126][ T7279] kcsan_report.cold+0xc/0x10 [ 51.752884][ T7279] __kcsan_setup_watchpoint+0x32e/0x4a0 [ 51.758407][ T7279] __tsan_read4+0x2c/0x30 [ 51.762713][ T7279] __tcp_select_window+0x6b/0x4d0 [ 51.767717][ T7279] __tcp_ack_snd_check+0x117/0x4f0 [ 51.772808][ T7279] tcp_rcv_established+0xce9/0xf50 [ 51.777898][ T7279] ? ipv4_dst_check+0xc6/0xf0 [ 51.782555][ T7279] tcp_v4_do_rcv+0x381/0x4e0 [ 51.787124][ T7279] __release_sock+0x135/0x1e0 [ 51.791778][ T7279] release_sock+0x61/0x160 [ 51.796171][ T7279] tcp_recvmsg+0x63b/0x1a30 [ 51.800653][ T7279] ? __kcsan_setup_watchpoint+0x6b/0x4a0 [ 51.806262][ T7279] inet_recvmsg+0xbb/0x250 [ 51.810652][ T7279] ? __tsan_read8+0x2c/0x30 [ 51.815252][ T7279] ? inet_sendpage+0x100/0x100 [ 51.819992][ T7279] sock_recvmsg+0x92/0xb0 [ 51.824300][ T7279] sock_read_iter+0x15f/0x1e0 [ 51.828969][ T7279] new_sync_read+0x389/0x4f0 [ 51.833549][ T7279] __vfs_read+0xb1/0xc0 [ 51.837680][ T7279] vfs_read+0x143/0x2c0 [ 51.841812][ T7279] ksys_read+0xd5/0x1b0 [ 51.845944][ T7279] __x64_sys_read+0x4c/0x60 [ 51.850430][ T7279] do_syscall_64+0xcc/0x370 [ 51.854912][ T7279] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 51.860776][ T7279] RIP: 0033:0x47c530 [ 51.864648][ T7279] 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 [ 51.884242][ T7279] RSP: 002b:000000c4204fd7d8 EFLAGS: 00000212 ORIG_RAX: 0000000000000000 [ 51.892636][ T7279] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000047c530 [ 51.900592][ T7279] RDX: 0000000000001000 RSI: 000000c420320000 RDI: 0000000000000003 [ 51.908538][ T7279] RBP: 000000c4204fd830 R08: 0000000000000000 R09: 0000000000000000 [ 51.916661][ T7279] R10: 0000000000000000 R11: 0000000000000212 R12: 0000000000000020 [ 51.924607][ T7279] R13: ffffffffffffffff R14: 0000000000000010 R15: ffffffffffffffff [ 51.934017][ T7279] Kernel Offset: disabled [ 51.938361][ T7279] Rebooting in 86400 seconds..