[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 35.010208][ T26] audit: type=1800 audit(1571778463.075:25): pid=7076 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 35.048311][ T26] audit: type=1800 audit(1571778463.075:26): pid=7076 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 35.085163][ T26] audit: type=1800 audit(1571778463.075:27): pid=7076 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 '10.128.0.137' (ECDSA) to the list of known hosts. 2019/10/22 21:07:51 fuzzer started 2019/10/22 21:07:53 dialing manager at 10.128.0.105:33369 2019/10/22 21:07:53 syscalls: 2524 2019/10/22 21:07:53 code coverage: enabled 2019/10/22 21:07:53 comparison tracing: enabled 2019/10/22 21:07:53 extra coverage: extra coverage is not supported by the kernel 2019/10/22 21:07:53 setuid sandbox: enabled 2019/10/22 21:07:53 namespace sandbox: enabled 2019/10/22 21:07:53 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/22 21:07:53 fault injection: enabled 2019/10/22 21:07:53 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/22 21:07:53 net packet injection: enabled 2019/10/22 21:07:53 net device setup: enabled 2019/10/22 21:07:53 concurrency sanitizer: enabled syzkaller login: [ 45.867138][ T7240] ================================================================== [ 45.875300][ T7240] BUG: KCSAN: data-race in tcp_add_backlog / tcp_recvmsg [ 45.882331][ T7240] [ 45.884682][ T7240] write to 0xffff8881232a89f8 of 8 bytes by interrupt on cpu 1: [ 45.892368][ T7240] tcp_add_backlog+0x45a/0xcc0 [ 45.897210][ T7240] tcp_v4_rcv+0x1a60/0x1bb0 [ 45.901705][ T7240] ip_protocol_deliver_rcu+0x4d/0x420 [ 45.907076][ T7240] ip_local_deliver_finish+0x110/0x140 [ 45.912516][ T7240] ip_local_deliver+0x133/0x210 [ 45.917346][ T7240] ip_rcv_finish+0x121/0x160 [ 45.921913][ T7240] ip_rcv+0x18f/0x1a0 [ 45.925962][ T7240] __netif_receive_skb_one_core+0xa7/0xe0 [ 45.931658][ T7240] __netif_receive_skb+0x37/0xf0 [ 45.936605][ T7240] netif_receive_skb_internal+0x59/0x190 [ 45.942215][ T7240] napi_gro_receive+0x28f/0x330 [ 45.947055][ T7240] receive_buf+0x284/0x30b0 [ 45.951547][ T7240] virtnet_poll+0x436/0x7d0 [ 45.956027][ T7240] net_rx_action+0x3ae/0xa90 [ 45.960589][ T7240] [ 45.962899][ T7240] read to 0xffff8881232a89f8 of 8 bytes by task 7240 on cpu 0: [ 45.970420][ T7240] tcp_recvmsg+0x470/0x1a30 [ 45.974903][ T7240] inet_recvmsg+0xbb/0x250 [ 45.979373][ T7240] sock_recvmsg+0x92/0xb0 [ 45.983841][ T7240] sock_read_iter+0x15f/0x1e0 [ 45.988518][ T7240] new_sync_read+0x389/0x4f0 [ 45.993084][ T7240] __vfs_read+0xb1/0xc0 [ 45.997216][ T7240] vfs_read+0x143/0x2c0 [ 46.001360][ T7240] ksys_read+0xd5/0x1b0 [ 46.005493][ T7240] __x64_sys_read+0x4c/0x60 [ 46.009996][ T7240] do_syscall_64+0xcc/0x370 [ 46.014479][ T7240] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 46.020341][ T7240] [ 46.022646][ T7240] Reported by Kernel Concurrency Sanitizer on: [ 46.028782][ T7240] CPU: 0 PID: 7240 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 46.036213][ T7240] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 46.046248][ T7240] ================================================================== [ 46.054305][ T7240] Kernel panic - not syncing: panic_on_warn set ... [ 46.060878][ T7240] CPU: 0 PID: 7240 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 46.068319][ T7240] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 46.078365][ T7240] Call Trace: [ 46.081648][ T7240] dump_stack+0xf5/0x159 [ 46.085885][ T7240] panic+0x210/0x640 [ 46.089830][ T7240] ? __x64_sys_read+0x4c/0x60 [ 46.094522][ T7240] ? vprintk_func+0x8d/0x140 [ 46.099101][ T7240] kcsan_report.cold+0xc/0x10 [ 46.103767][ T7240] __kcsan_setup_watchpoint+0x32e/0x4a0 [ 46.109297][ T7240] __tsan_read8+0x2c/0x30 [ 46.113630][ T7240] tcp_recvmsg+0x470/0x1a30 [ 46.118125][ T7240] inet_recvmsg+0xbb/0x250 [ 46.122524][ T7240] ? __tsan_read8+0x2c/0x30 [ 46.127034][ T7240] ? inet_sendpage+0x100/0x100 [ 46.131870][ T7240] sock_recvmsg+0x92/0xb0 [ 46.136183][ T7240] sock_read_iter+0x15f/0x1e0 [ 46.140851][ T7240] new_sync_read+0x389/0x4f0 [ 46.145430][ T7240] __vfs_read+0xb1/0xc0 [ 46.149569][ T7240] vfs_read+0x143/0x2c0 [ 46.153714][ T7240] ksys_read+0xd5/0x1b0 [ 46.157870][ T7240] __x64_sys_read+0x4c/0x60 [ 46.162363][ T7240] do_syscall_64+0xcc/0x370 [ 46.166867][ T7240] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 46.172739][ T7240] RIP: 0033:0x47c530 [ 46.176620][ T7240] 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 [ 46.196217][ T7240] RSP: 002b:000000c4203c57d8 EFLAGS: 00000212 ORIG_RAX: 0000000000000000 [ 46.204610][ T7240] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000047c530 [ 46.212563][ T7240] RDX: 0000000000001000 RSI: 000000c4202e6000 RDI: 0000000000000003 [ 46.221282][ T7240] RBP: 000000c4203c5830 R08: 0000000000000000 R09: 0000000000000000 [ 46.229257][ T7240] R10: 0000000000000000 R11: 0000000000000212 R12: 0000000000000040 [ 46.237216][ T7240] R13: ffffffffffffffff R14: 0000000000000002 R15: ffffffffffffffff [ 46.247943][ T7240] Kernel Offset: disabled [ 46.252283][ T7240] Rebooting in 86400 seconds..