[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 33.829313][ T26] audit: type=1800 audit(1571452328.429:25): pid=6980 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 33.867915][ T26] audit: type=1800 audit(1571452328.429:26): pid=6980 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 33.891507][ T26] audit: type=1800 audit(1571452328.429:27): pid=6980 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 '10.128.0.17' (ECDSA) to the list of known hosts. 2019/10/19 02:32:19 fuzzer started 2019/10/19 02:32:20 dialing manager at 10.128.0.105:43535 2019/10/19 02:32:21 syscalls: 2524 2019/10/19 02:32:21 code coverage: enabled 2019/10/19 02:32:21 comparison tracing: enabled 2019/10/19 02:32:21 extra coverage: extra coverage is not supported by the kernel 2019/10/19 02:32:21 setuid sandbox: enabled 2019/10/19 02:32:21 namespace sandbox: enabled 2019/10/19 02:32:21 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/19 02:32:21 fault injection: enabled 2019/10/19 02:32:21 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/19 02:32:21 net packet injection: enabled 2019/10/19 02:32:21 net device setup: enabled 2019/10/19 02:32:21 concurrency sanitizer: enabled syzkaller login: [ 46.963784][ T7133] ================================================================== [ 46.971910][ T7133] BUG: KCSAN: data-race in tcp_add_backlog / tcp_rcv_space_adjust [ 46.979692][ T7133] [ 46.982017][ T7133] read to 0xffff8881256b930c of 4 bytes by interrupt on cpu 0: [ 46.989546][ T7133] tcp_add_backlog+0x43/0xcc0 [ 46.994263][ T7133] tcp_v4_rcv+0x1a60/0x1bb0 [ 46.998740][ T7133] ip_protocol_deliver_rcu+0x4d/0x420 [ 47.004085][ T7133] ip_local_deliver_finish+0x110/0x140 [ 47.009556][ T7133] ip_local_deliver+0x133/0x210 [ 47.014379][ T7133] ip_rcv_finish+0x121/0x160 [ 47.018942][ T7133] ip_rcv+0x18f/0x1a0 [ 47.022913][ T7133] __netif_receive_skb_one_core+0xa7/0xe0 [ 47.028619][ T7133] __netif_receive_skb+0x37/0xf0 [ 47.033537][ T7133] netif_receive_skb_internal+0x59/0x190 [ 47.039142][ T7133] napi_gro_receive+0x28f/0x330 [ 47.043972][ T7133] receive_buf+0x284/0x30b0 [ 47.048623][ T7133] virtnet_poll+0x436/0x7d0 [ 47.053103][ T7133] net_rx_action+0x3ae/0xa90 [ 47.057658][ T7133] [ 47.059965][ T7133] write to 0xffff8881256b930c of 4 bytes by task 7133 on cpu 1: [ 47.067565][ T7133] tcp_rcv_space_adjust+0x40f/0x4c0 [ 47.072752][ T7133] tcp_recvmsg+0xdaa/0x1a30 [ 47.077231][ T7133] inet_recvmsg+0xbb/0x250 [ 47.081727][ T7133] sock_recvmsg+0x92/0xb0 [ 47.086031][ T7133] sock_read_iter+0x15f/0x1e0 [ 47.090694][ T7133] new_sync_read+0x389/0x4f0 [ 47.095256][ T7133] __vfs_read+0xb1/0xc0 [ 47.099382][ T7133] vfs_read+0x143/0x2c0 [ 47.103520][ T7133] ksys_read+0xd5/0x1b0 [ 47.107651][ T7133] __x64_sys_read+0x4c/0x60 [ 47.112132][ T7133] do_syscall_64+0xcc/0x370 [ 47.116610][ T7133] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 47.122471][ T7133] [ 47.124772][ T7133] Reported by Kernel Concurrency Sanitizer on: [ 47.130902][ T7133] CPU: 1 PID: 7133 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 47.138326][ T7133] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 47.148353][ T7133] ================================================================== [ 47.156384][ T7133] Kernel panic - not syncing: panic_on_warn set ... [ 47.162950][ T7133] CPU: 1 PID: 7133 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 47.170376][ T7133] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 47.180405][ T7133] Call Trace: [ 47.183672][ T7133] dump_stack+0xf5/0x159 [ 47.187891][ T7133] panic+0x210/0x640 [ 47.191766][ T7133] ? ksys_read+0xd5/0x1b0 [ 47.196071][ T7133] ? vprintk_func+0x8d/0x140 [ 47.200636][ T7133] kcsan_report.cold+0xc/0x10 [ 47.205287][ T7133] __kcsan_setup_watchpoint+0x32e/0x4a0 [ 47.210820][ T7133] __tsan_write4+0x32/0x40 [ 47.215211][ T7133] tcp_rcv_space_adjust+0x40f/0x4c0 [ 47.220392][ T7133] tcp_recvmsg+0xdaa/0x1a30 [ 47.224888][ T7133] ? __kcsan_setup_watchpoint+0x6b/0x4a0 [ 47.230506][ T7133] inet_recvmsg+0xbb/0x250 [ 47.234895][ T7133] ? __tsan_read8+0x2c/0x30 [ 47.239385][ T7133] ? inet_sendpage+0x100/0x100 [ 47.244127][ T7133] sock_recvmsg+0x92/0xb0 [ 47.248436][ T7133] sock_read_iter+0x15f/0x1e0 [ 47.253093][ T7133] new_sync_read+0x389/0x4f0 [ 47.257663][ T7133] __vfs_read+0xb1/0xc0 [ 47.261795][ T7133] vfs_read+0x143/0x2c0 [ 47.265929][ T7133] ksys_read+0xd5/0x1b0 [ 47.270075][ T7133] __x64_sys_read+0x4c/0x60 [ 47.274557][ T7133] do_syscall_64+0xcc/0x370 [ 47.279035][ T7133] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 47.284899][ T7133] RIP: 0033:0x47c530 [ 47.288785][ T7133] 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 [ 47.308541][ T7133] RSP: 002b:000000c4203358b8 EFLAGS: 00000212 ORIG_RAX: 0000000000000000 [ 47.316942][ T7133] RAX: ffffffffffffffda RBX: 000000000181f3a0 RCX: 000000000047c530 [ 47.324889][ T7133] RDX: 0000000000001000 RSI: 000000c4200a2000 RDI: 0000000000000003 [ 47.332836][ T7133] RBP: 000000c420335910 R08: 0000000000000000 R09: 0000000000000000 [ 47.340782][ T7133] R10: 0000000000000000 R11: 0000000000000212 R12: 00000000000000a0 [ 47.348739][ T7133] R13: 00000000000000ff R14: 00007f22aa7a5000 R15: 0000000000000004 [ 47.357917][ T7133] Kernel Offset: disabled [ 47.362345][ T7133] Rebooting in 86400 seconds..