[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 35.854125][ T25] audit: type=1800 audit(1571715577.492:25): pid=7130 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 35.873948][ T25] audit: type=1800 audit(1571715577.492:26): pid=7130 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 35.894189][ T25] audit: type=1800 audit(1571715577.492:27): pid=7130 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 '10.128.0.203' (ECDSA) to the list of known hosts. 2019/10/22 03:39:44 fuzzer started 2019/10/22 03:39:46 dialing manager at 10.128.0.105:37053 2019/10/22 03:39:46 syscalls: 2524 2019/10/22 03:39:46 code coverage: enabled 2019/10/22 03:39:46 comparison tracing: enabled 2019/10/22 03:39:46 extra coverage: extra coverage is not supported by the kernel 2019/10/22 03:39:46 setuid sandbox: enabled 2019/10/22 03:39:46 namespace sandbox: enabled 2019/10/22 03:39:46 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/22 03:39:46 fault injection: enabled 2019/10/22 03:39:46 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/22 03:39:46 net packet injection: enabled 2019/10/22 03:39:46 net device setup: enabled 2019/10/22 03:39:46 concurrency sanitizer: enabled syzkaller login: [ 45.453007][ T7296] ================================================================== [ 45.461141][ T7296] BUG: KCSAN: data-race in tcp_poll / tcp_queue_rcv [ 45.469685][ T7296] [ 45.472756][ T7296] write to 0xffff888122ba25b8 of 4 bytes by interrupt on cpu 0: [ 45.481019][ T7296] tcp_queue_rcv+0xe9/0x380 [ 45.485855][ T7296] tcp_rcv_established+0xbf1/0xf50 [ 45.490985][ T7296] tcp_v4_do_rcv+0x381/0x4e0 [ 45.495830][ T7296] tcp_v4_rcv+0x19dc/0x1bb0 [ 45.500942][ T7296] ip_protocol_deliver_rcu+0x4d/0x420 [ 45.506590][ T7296] ip_local_deliver_finish+0x110/0x140 [ 45.513955][ T7296] ip_local_deliver+0x133/0x210 [ 45.519201][ T7296] ip_rcv_finish+0x121/0x160 [ 45.523905][ T7296] ip_rcv+0x18f/0x1a0 [ 45.527887][ T7296] __netif_receive_skb_one_core+0xa7/0xe0 [ 45.533946][ T7296] __netif_receive_skb+0x37/0xf0 [ 45.538894][ T7296] netif_receive_skb_internal+0x59/0x190 [ 45.544716][ T7296] napi_gro_receive+0x28f/0x330 [ 45.549583][ T7296] receive_buf+0x284/0x30b0 [ 45.554075][ T7296] [ 45.556414][ T7296] read to 0xffff888122ba25b8 of 4 bytes by task 7296 on cpu 1: [ 45.563944][ T7296] tcp_poll+0x204/0x6b0 [ 45.568079][ T7296] sock_poll+0xed/0x250 [ 45.572345][ T7296] ep_item_poll.isra.0+0x90/0x190 [ 45.577374][ T7296] ep_send_events_proc+0x113/0x590 [ 45.582470][ T7296] ep_scan_ready_list.constprop.0+0x189/0x500 [ 45.590276][ T7296] ep_poll+0xe3/0x900 [ 45.594259][ T7296] do_epoll_wait+0x162/0x180 [ 45.598858][ T7296] __x64_sys_epoll_pwait+0xcd/0x180 [ 45.604065][ T7296] do_syscall_64+0xcc/0x370 [ 45.608568][ T7296] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 45.614446][ T7296] [ 45.616819][ T7296] Reported by Kernel Concurrency Sanitizer on: [ 45.623082][ T7296] CPU: 1 PID: 7296 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 45.630837][ T7296] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 45.641123][ T7296] ================================================================== [ 45.649182][ T7296] Kernel panic - not syncing: panic_on_warn set ... [ 45.656007][ T7296] CPU: 1 PID: 7296 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 45.663772][ T7296] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 45.673813][ T7296] Call Trace: [ 45.677233][ T7296] dump_stack+0xf5/0x159 [ 45.681530][ T7296] panic+0x210/0x640 [ 45.685418][ T7296] ? do_syscall_64+0xcc/0x370 [ 45.691239][ T7296] ? vprintk_func+0x8d/0x140 [ 45.695829][ T7296] kcsan_report.cold+0xc/0x10 [ 45.700497][ T7296] __kcsan_setup_watchpoint+0x32e/0x4a0 [ 45.706024][ T7296] __tsan_read4+0x2c/0x30 [ 45.710335][ T7296] tcp_poll+0x204/0x6b0 [ 45.714483][ T7296] ? tcp_alloc_md5sig_pool+0x320/0x320 [ 45.719925][ T7296] sock_poll+0xed/0x250 [ 45.724061][ T7296] ? sock_read_iter+0x1e0/0x1e0 [ 45.728901][ T7296] ep_item_poll.isra.0+0x90/0x190 [ 45.733921][ T7296] ep_send_events_proc+0x113/0x590 [ 45.739016][ T7296] ? __schedule+0x319/0x640 [ 45.743664][ T7296] ? __kcsan_setup_watchpoint+0x6b/0x4a0 [ 45.749298][ T7296] ep_scan_ready_list.constprop.0+0x189/0x500 [ 45.755502][ T7296] ? ep_loop_check_proc+0x2f0/0x2f0 [ 45.760714][ T7296] ep_poll+0xe3/0x900 [ 45.764686][ T7296] ? wake_up_q+0x70/0x70 [ 45.769067][ T7296] do_epoll_wait+0x162/0x180 [ 45.773674][ T7296] __x64_sys_epoll_pwait+0xcd/0x180 [ 45.778902][ T7296] do_syscall_64+0xcc/0x370 [ 45.783400][ T7296] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 45.789293][ T7296] RIP: 0033:0x45b300 [ 45.793170][ T7296] Code: 0f 05 89 44 24 20 c3 cc cc cc 8b 7c 24 08 48 8b 74 24 10 8b 54 24 18 44 8b 54 24 1c 49 c7 c0 00 00 00 00 b8 19 01 00 00 0f 05 <89> 44 24 20 c3 cc cc cc cc cc cc cc cc cc cc cc 8b 7c 24 08 48 c7 [ 45.812769][ T7296] RSP: 002b:000000c42004b860 EFLAGS: 00000246 ORIG_RAX: 0000000000000119 [ 45.821300][ T7296] RAX: ffffffffffffffda RBX: 00000000ffffffff RCX: 000000000045b300 [ 45.829287][ T7296] RDX: 0000000000000080 RSI: 000000c42004b8a0 RDI: 0000000000000004 [ 45.837270][ T7296] RBP: 000000c42004bea0 R08: 0000000000000000 R09: 0000000000000000 [ 45.845333][ T7296] R10: 00000000ffffffff R11: 0000000000000246 R12: 0000000000000200 [ 45.853465][ T7296] R13: ffffffffffffffff R14: 0000000000000002 R15: ffffffffffffffff [ 45.862981][ T7296] Kernel Offset: disabled [ 45.867329][ T7296] Rebooting in 86400 seconds..