[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 38.635832][ T25] audit: type=1800 audit(1572773175.088:25): pid=7095 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 38.663705][ T25] audit: type=1800 audit(1572773175.088:26): pid=7095 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 38.692170][ T25] audit: type=1800 audit(1572773175.088:27): pid=7095 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 '10.128.0.223' (ECDSA) to the list of known hosts. 2019/11/03 09:26:25 fuzzer started 2019/11/03 09:26:27 dialing manager at 10.128.0.105:43165 2019/11/03 09:26:27 syscalls: 2554 2019/11/03 09:26:27 code coverage: enabled 2019/11/03 09:26:27 comparison tracing: enabled 2019/11/03 09:26:27 extra coverage: extra coverage is not supported by the kernel 2019/11/03 09:26:27 setuid sandbox: enabled 2019/11/03 09:26:27 namespace sandbox: enabled 2019/11/03 09:26:27 Android sandbox: /sys/fs/selinux/policy does not exist 2019/11/03 09:26:27 fault injection: enabled 2019/11/03 09:26:27 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/11/03 09:26:27 net packet injection: enabled 2019/11/03 09:26:27 net device setup: enabled 2019/11/03 09:26:27 concurrency sanitizer: enabled 2019/11/03 09:26:27 adding functions to KCSAN blacklist: 'tick_sched_do_timer' '__hrtimer_run_queues' 'task_dump_owner' syzkaller login: [ 50.905657][ T7268] ================================================================== [ 50.913818][ T7268] BUG: KCSAN: data-race in tcp_add_backlog / tcp_recvmsg [ 50.922025][ T7268] [ 50.924346][ T7268] write to 0xffff888126ade138 of 8 bytes by interrupt on cpu 1: [ 50.931964][ T7268] tcp_add_backlog+0x45a/0xcc0 [ 50.936805][ T7268] tcp_v4_rcv+0x1a60/0x1bb0 [ 50.941287][ T7268] ip_protocol_deliver_rcu+0x4d/0x420 [ 50.946732][ T7268] ip_local_deliver_finish+0x110/0x140 [ 50.952176][ T7268] ip_local_deliver+0x133/0x210 [ 50.957025][ T7268] ip_rcv_finish+0x121/0x160 [ 50.961710][ T7268] ip_rcv+0x18f/0x1a0 [ 50.965708][ T7268] __netif_receive_skb_one_core+0xa7/0xe0 [ 50.971678][ T7268] __netif_receive_skb+0x37/0xf0 [ 50.976693][ T7268] netif_receive_skb_internal+0x59/0x190 [ 50.982306][ T7268] napi_gro_receive+0x28f/0x330 [ 50.987173][ T7268] receive_buf+0x284/0x30b0 [ 50.991741][ T7268] virtnet_poll+0x436/0x7d0 [ 50.996229][ T7268] net_rx_action+0x3ae/0xa90 [ 51.000792][ T7268] [ 51.003115][ T7268] read to 0xffff888126ade138 of 8 bytes by task 7268 on cpu 0: [ 51.010634][ T7268] tcp_recvmsg+0x470/0x1a30 [ 51.015113][ T7268] inet_recvmsg+0xbb/0x250 [ 51.019511][ T7268] sock_recvmsg+0x92/0xb0 [ 51.023823][ T7268] sock_read_iter+0x15f/0x1e0 [ 51.028645][ T7268] new_sync_read+0x389/0x4f0 [ 51.033228][ T7268] __vfs_read+0xb1/0xc0 [ 51.037363][ T7268] vfs_read+0x143/0x2c0 [ 51.041495][ T7268] ksys_read+0xd5/0x1b0 [ 51.045651][ T7268] __x64_sys_read+0x4c/0x60 [ 51.050356][ T7268] do_syscall_64+0xcc/0x370 [ 51.054991][ T7268] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 51.060859][ T7268] [ 51.063164][ T7268] Reported by Kernel Concurrency Sanitizer on: [ 51.069327][ T7268] CPU: 0 PID: 7268 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 51.076849][ T7268] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 51.087147][ T7268] ================================================================== [ 51.095188][ T7268] Kernel panic - not syncing: panic_on_warn set ... [ 51.101957][ T7268] CPU: 0 PID: 7268 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 51.109401][ T7268] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 51.119453][ T7268] Call Trace: [ 51.122727][ T7268] dump_stack+0xf5/0x159 [ 51.126949][ T7268] panic+0x210/0x640 [ 51.130842][ T7268] ? __x64_sys_read+0x4c/0x60 [ 51.135507][ T7268] ? vprintk_func+0x8d/0x140 [ 51.140087][ T7268] kcsan_report.cold+0xc/0x10 [ 51.144742][ T7268] __kcsan_setup_watchpoint+0x32e/0x4a0 [ 51.150266][ T7268] __tsan_read8+0x2c/0x30 [ 51.154578][ T7268] tcp_recvmsg+0x470/0x1a30 [ 51.159223][ T7268] inet_recvmsg+0xbb/0x250 [ 51.163735][ T7268] ? __tsan_read8+0x2c/0x30 [ 51.168253][ T7268] ? inet_sendpage+0x100/0x100 [ 51.173003][ T7268] sock_recvmsg+0x92/0xb0 [ 51.177403][ T7268] sock_read_iter+0x15f/0x1e0 [ 51.182168][ T7268] new_sync_read+0x389/0x4f0 [ 51.186742][ T7268] __vfs_read+0xb1/0xc0 [ 51.190876][ T7268] vfs_read+0x143/0x2c0 [ 51.195444][ T7268] ksys_read+0xd5/0x1b0 [ 51.199578][ T7268] __x64_sys_read+0x4c/0x60 [ 51.204073][ T7268] do_syscall_64+0xcc/0x370 [ 51.208573][ T7268] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 51.214446][ T7268] RIP: 0033:0x47c530 [ 51.218328][ T7268] 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 [ 51.237928][ T7268] RSP: 002b:000000c42033b810 EFLAGS: 00000202 ORIG_RAX: 0000000000000000 [ 51.246679][ T7268] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000047c530 [ 51.254720][ T7268] RDX: 0000000000001000 RSI: 000000c42031c000 RDI: 0000000000000003 [ 51.262675][ T7268] RBP: 000000c42033b868 R08: 0000000000000000 R09: 0000000000000000 [ 51.270624][ T7268] R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000040 [ 51.278572][ T7268] R13: ffffffffffffffff R14: 0000000000000002 R15: ffffffffffffffff [ 51.288046][ T7268] Kernel Offset: disabled [ 51.292370][ T7268] Rebooting in 86400 seconds..