[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 34.124140][ T23] audit: type=1800 audit(1571752177.852:25): pid=7038 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 34.158276][ T23] audit: type=1800 audit(1571752177.852:26): pid=7038 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 34.180791][ T23] audit: type=1800 audit(1571752177.862:27): pid=7038 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 '10.128.0.182' (ECDSA) to the list of known hosts. 2019/10/22 13:49:49 fuzzer started 2019/10/22 13:49:50 dialing manager at 10.128.0.105:37053 2019/10/22 13:49:50 syscalls: 2524 2019/10/22 13:49:50 code coverage: enabled 2019/10/22 13:49:50 comparison tracing: enabled 2019/10/22 13:49:50 extra coverage: extra coverage is not supported by the kernel 2019/10/22 13:49:50 setuid sandbox: enabled 2019/10/22 13:49:50 namespace sandbox: enabled 2019/10/22 13:49:50 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/22 13:49:50 fault injection: enabled 2019/10/22 13:49:50 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/22 13:49:50 net packet injection: enabled 2019/10/22 13:49:50 net device setup: enabled 2019/10/22 13:49:50 concurrency sanitizer: enabled syzkaller login: [ 47.485286][ T7186] ================================================================== [ 47.493427][ T7186] BUG: KCSAN: data-race in tcp_add_backlog / tcp_recvmsg [ 47.500431][ T7186] [ 47.502741][ T7186] write to 0xffff8881265369f8 of 8 bytes by interrupt on cpu 1: [ 47.510352][ T7186] tcp_add_backlog+0x45a/0xcc0 [ 47.515099][ T7186] tcp_v4_rcv+0x1a60/0x1bb0 [ 47.519786][ T7186] ip_protocol_deliver_rcu+0x4d/0x420 [ 47.525138][ T7186] ip_local_deliver_finish+0x110/0x140 [ 47.530587][ T7186] ip_local_deliver+0x133/0x210 [ 47.535412][ T7186] ip_rcv_finish+0x121/0x160 [ 47.539977][ T7186] ip_rcv+0x18f/0x1a0 [ 47.543945][ T7186] __netif_receive_skb_one_core+0xa7/0xe0 [ 47.549641][ T7186] __netif_receive_skb+0x37/0xf0 [ 47.554558][ T7186] netif_receive_skb_internal+0x59/0x190 [ 47.560182][ T7186] napi_gro_receive+0x28f/0x330 [ 47.565013][ T7186] receive_buf+0x284/0x30b0 [ 47.569492][ T7186] virtnet_poll+0x436/0x7d0 [ 47.573972][ T7186] net_rx_action+0x3ae/0xa90 [ 47.578554][ T7186] [ 47.580952][ T7186] read to 0xffff8881265369f8 of 8 bytes by task 7186 on cpu 0: [ 47.588475][ T7186] tcp_recvmsg+0x470/0x1a30 [ 47.592956][ T7186] inet_recvmsg+0xbb/0x250 [ 47.597351][ T7186] sock_recvmsg+0x92/0xb0 [ 47.601668][ T7186] sock_read_iter+0x15f/0x1e0 [ 47.606323][ T7186] new_sync_read+0x389/0x4f0 [ 47.611015][ T7186] __vfs_read+0xb1/0xc0 [ 47.615156][ T7186] vfs_read+0x143/0x2c0 [ 47.619289][ T7186] ksys_read+0xd5/0x1b0 [ 47.623421][ T7186] __x64_sys_read+0x4c/0x60 [ 47.627907][ T7186] do_syscall_64+0xcc/0x370 [ 47.632387][ T7186] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 47.638259][ T7186] [ 47.640714][ T7186] Reported by Kernel Concurrency Sanitizer on: [ 47.646858][ T7186] CPU: 0 PID: 7186 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 47.654296][ T7186] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 47.664343][ T7186] ================================================================== [ 47.672386][ T7186] Kernel panic - not syncing: panic_on_warn set ... [ 47.678954][ T7186] CPU: 0 PID: 7186 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 47.686383][ T7186] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 47.696644][ T7186] Call Trace: [ 47.699925][ T7186] dump_stack+0xf5/0x159 [ 47.704148][ T7186] panic+0x210/0x640 [ 47.708026][ T7186] ? __x64_sys_read+0x4c/0x60 [ 47.712682][ T7186] ? vprintk_func+0x8d/0x140 [ 47.717255][ T7186] kcsan_report.cold+0xc/0x10 [ 47.721925][ T7186] __kcsan_setup_watchpoint+0x32e/0x4a0 [ 47.727465][ T7186] __tsan_read8+0x2c/0x30 [ 47.731778][ T7186] tcp_recvmsg+0x470/0x1a30 [ 47.736269][ T7186] inet_recvmsg+0xbb/0x250 [ 47.740666][ T7186] ? __tsan_read8+0x2c/0x30 [ 47.745149][ T7186] ? inet_sendpage+0x100/0x100 [ 47.749893][ T7186] sock_recvmsg+0x92/0xb0 [ 47.754208][ T7186] sock_read_iter+0x15f/0x1e0 [ 47.758869][ T7186] new_sync_read+0x389/0x4f0 [ 47.763445][ T7186] __vfs_read+0xb1/0xc0 [ 47.767584][ T7186] vfs_read+0x143/0x2c0 [ 47.771723][ T7186] ksys_read+0xd5/0x1b0 [ 47.775878][ T7186] __x64_sys_read+0x4c/0x60 [ 47.780385][ T7186] do_syscall_64+0xcc/0x370 [ 47.784874][ T7186] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 47.790742][ T7186] RIP: 0033:0x47c530 [ 47.794620][ T7186] 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 [ 47.814216][ T7186] RSP: 002b:000000c4204eb7d8 EFLAGS: 00000212 ORIG_RAX: 0000000000000000 [ 47.822609][ T7186] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000047c530 [ 47.830557][ T7186] RDX: 0000000000001000 RSI: 000000c4203e0000 RDI: 0000000000000003 [ 47.838508][ T7186] RBP: 000000c4204eb830 R08: 0000000000000000 R09: 0000000000000000 [ 47.846460][ T7186] R10: 0000000000000000 R11: 0000000000000212 R12: 0000000000000200 [ 47.854411][ T7186] R13: ffffffffffffffff R14: 0000000000000002 R15: ffffffffffffffff [ 47.863669][ T7186] Kernel Offset: disabled [ 47.868011][ T7186] Rebooting in 86400 seconds..