[ 36.306810][ T25] audit: type=1800 audit(1572214765.758:22): pid=7254 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="motd" dev="sda1" ino=2480 res=0 [ 36.327584][ T25] audit: type=1800 audit(1572214765.758:23): pid=7254 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="rsyslog" dev="sda1" ino=2475 res=0 [ 36.355349][ T25] audit: type=1800 audit(1572214765.758:24): pid=7254 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="sudo" dev="sda1" ino=2487 res=0 [....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [....] 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 '10.128.0.69' (ECDSA) to the list of known hosts. 2019/10/27 22:19:36 fuzzer started 2019/10/27 22:19:37 dialing manager at 10.128.0.105:33655 2019/10/27 22:19:38 syscalls: 2533 2019/10/27 22:19:38 code coverage: enabled 2019/10/27 22:19:38 comparison tracing: enabled 2019/10/27 22:19:38 extra coverage: extra coverage is not supported by the kernel 2019/10/27 22:19:38 setuid sandbox: enabled 2019/10/27 22:19:38 namespace sandbox: enabled 2019/10/27 22:19:38 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/27 22:19:38 fault injection: enabled 2019/10/27 22:19:38 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/27 22:19:38 net packet injection: enabled 2019/10/27 22:19:38 net device setup: enabled 2019/10/27 22:19:38 concurrency sanitizer: enabled syzkaller login: [ 48.578686][ T7408] ================================================================== [ 48.586862][ T7408] BUG: KCSAN: data-race in tcp_ack / tcp_poll [ 48.592910][ T7408] [ 48.595261][ T7408] write to 0xffff888126bf8a48 of 4 bytes by interrupt on cpu 1: [ 48.602882][ T7408] tcp_ack+0xf2c/0x3170 [ 48.607029][ T7408] tcp_rcv_established+0x37e/0xf50 [ 48.612134][ T7408] tcp_v4_do_rcv+0x381/0x4e0 [ 48.616714][ T7408] tcp_v4_rcv+0x19dc/0x1bb0 [ 48.621204][ T7408] ip_protocol_deliver_rcu+0x4d/0x420 [ 48.626561][ T7408] ip_local_deliver_finish+0x110/0x140 [ 48.632007][ T7408] ip_local_deliver+0x133/0x210 [ 48.636842][ T7408] ip_rcv_finish+0x121/0x160 [ 48.641420][ T7408] ip_rcv+0x18f/0x1a0 [ 48.645393][ T7408] __netif_receive_skb_one_core+0xa7/0xe0 [ 48.651100][ T7408] __netif_receive_skb+0x37/0xf0 [ 48.656025][ T7408] netif_receive_skb_internal+0x59/0x190 [ 48.661643][ T7408] napi_gro_receive+0x28f/0x330 [ 48.666479][ T7408] receive_buf+0x284/0x30b0 [ 48.670962][ T7408] [ 48.673281][ T7408] read to 0xffff888126bf8a48 of 4 bytes by task 7408 on cpu 0: [ 48.680811][ T7408] tcp_poll+0x422/0x6b0 [ 48.684962][ T7408] sock_poll+0xed/0x250 [ 48.689107][ T7408] do_select+0x7d0/0x1020 [ 48.693424][ T7408] core_sys_select+0x381/0x550 [ 48.698178][ T7408] kern_select+0x106/0x170 [ 48.702578][ T7408] __x64_sys_select+0x70/0x90 [ 48.707243][ T7408] do_syscall_64+0xcc/0x370 [ 48.711740][ T7408] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 48.717607][ T7408] [ 48.719920][ T7408] Reported by Kernel Concurrency Sanitizer on: [ 48.726066][ T7408] CPU: 0 PID: 7408 Comm: sshd Not tainted 5.4.0-rc3+ #0 [ 48.732992][ T7408] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 48.743133][ T7408] ================================================================== [ 48.751194][ T7408] Kernel panic - not syncing: panic_on_warn set ... [ 48.757779][ T7408] CPU: 0 PID: 7408 Comm: sshd Not tainted 5.4.0-rc3+ #0 [ 48.764691][ T7408] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 48.774728][ T7408] Call Trace: [ 48.778014][ T7408] dump_stack+0xf5/0x159 [ 48.782253][ T7408] panic+0x210/0x640 [ 48.786145][ T7408] ? vprintk_func+0x8d/0x140 [ 48.790730][ T7408] kcsan_report.cold+0xc/0x10 [ 48.795397][ T7408] __kcsan_setup_watchpoint+0x32e/0x4a0 [ 48.800940][ T7408] __tsan_read4+0x2c/0x30 [ 48.805274][ T7408] tcp_poll+0x422/0x6b0 [ 48.809424][ T7408] ? tcp_alloc_md5sig_pool+0x320/0x320 [ 48.814875][ T7408] sock_poll+0xed/0x250 [ 48.819030][ T7408] ? sock_read_iter+0x1e0/0x1e0 [ 48.823871][ T7408] do_select+0x7d0/0x1020 [ 48.828192][ T7408] ? __tsan_read8+0x2c/0x30 [ 48.832705][ T7408] ? iov_iter_advance+0x211/0x9d0 [ 48.837718][ T7408] ? poll_initwait+0xa0/0xa0 [ 48.842304][ T7408] ? poll_select_finish+0x440/0x440 [ 48.847497][ T7408] ? tcp_push+0x1f3/0x3d0 [ 48.851819][ T7408] ? sock_zerocopy_put+0x78/0x90 [ 48.856747][ T7408] ? tcp_sendmsg_locked+0xbe4/0x1f30 [ 48.862027][ T7408] ? __kcsan_setup_watchpoint+0x6b/0x4a0 [ 48.867652][ T7408] ? __kcsan_setup_watchpoint+0x6b/0x4a0 [ 48.873273][ T7408] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 48.879506][ T7408] ? __this_cpu_preempt_check+0x4a/0x170 [ 48.885129][ T7408] ? __local_bh_enable_ip+0x32/0x80 [ 48.890316][ T7408] ? __kcsan_setup_watchpoint+0x6b/0x4a0 [ 48.895937][ T7408] ? _raw_spin_unlock_bh+0x44/0x50 [ 48.901038][ T7408] ? __tsan_read8+0x2c/0x30 [ 48.905525][ T7408] ? __kcsan_setup_watchpoint+0x6b/0x4a0 [ 48.911148][ T7408] ? check_stack_object+0xda/0x110 [ 48.916252][ T7408] ? __kcsan_setup_watchpoint+0x6b/0x4a0 [ 48.921875][ T7408] ? __tsan_read8+0x2c/0x30 [ 48.926372][ T7408] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 48.932606][ T7408] core_sys_select+0x381/0x550 [ 48.937372][ T7408] ? __kcsan_setup_watchpoint+0x6b/0x4a0 [ 48.942993][ T7408] ? __tsan_read8+0x2c/0x30 [ 48.947489][ T7408] ? __sanitizer_cov_trace_switch+0x49/0x80 [ 48.953369][ T7408] ? __tsan_write8+0x32/0x40 [ 48.957951][ T7408] ? ktime_get_ts64+0x286/0x2c0 [ 48.962795][ T7408] ? __sanitizer_cov_trace_cmp8+0x18/0x20 [ 48.968506][ T7408] ? timespec64_add_safe+0xae/0xd0 [ 48.973614][ T7408] kern_select+0x106/0x170 [ 48.978023][ T7408] __x64_sys_select+0x70/0x90 [ 48.982693][ T7408] do_syscall_64+0xcc/0x370 [ 48.987193][ T7408] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 48.993072][ T7408] RIP: 0033:0x7f962d10fdd3 [ 48.998744][ T7408] Code: 48 29 c2 64 89 11 48 83 c8 ff eb ea 90 90 90 90 90 90 90 90 90 90 90 83 3d 25 48 2b 00 00 75 13 49 89 ca b8 17 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 34 c3 48 83 ec 08 e8 ab 2f 01 00 48 89 04 24 [ 49.020732][ T7408] RSP: 002b:00007ffd8675eb08 EFLAGS: 00000246 ORIG_RAX: 0000000000000017 [ 49.029160][ T7408] RAX: ffffffffffffffda RBX: 00007ffd8675eb90 RCX: 00007f962d10fdd3 [ 49.037586][ T7408] RDX: 000055f45e356b20 RSI: 000055f45e356b40 RDI: 000000000000000c [ 49.045706][ T7408] RBP: 000055f45dc378dc R08: 00007ffd8675eb30 R09: 0101010101010101 [ 49.053823][ T7408] R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffd8675eb98 [ 49.062137][ T7408] R13: 0000000000000000 R14: 00007ffd8675eb88 R15: 00007ffd8675eb8c [ 49.071510][ T7408] Kernel Offset: disabled [ 49.075888][ T7408] Rebooting in 86400 seconds..