[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 39.079320] audit: type=1800 audit(1545711408.531:25): pid=7858 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2414 res=0 [ 39.125622] audit: type=1800 audit(1545711408.531:26): pid=7858 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2457 res=0 [ 39.154398] audit: type=1800 audit(1545711408.541:27): pid=7858 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="restorecond" dev="sda1" ino=2436 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 '10.128.15.226' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 47.958221] ------------[ cut here ]------------ [ 47.963250] do not call blocking ops when !TASK_RUNNING; state=1 set at [<0000000074763c31>] n_hdlc_tty_read+0x301/0x7f0 [ 47.974507] WARNING: CPU: 1 PID: 8011 at kernel/sched/core.c:6099 __might_sleep+0x13d/0x190 [ 47.982995] Kernel panic - not syncing: panic_on_warn set ... [ 47.988879] CPU: 1 PID: 8011 Comm: syz-executor385 Not tainted 4.20.0 #290 [ 47.995894] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 48.005275] Call Trace: [ 48.007848] dump_stack+0x1d3/0x2c6 [ 48.011466] ? dump_stack_print_info.cold.1+0x20/0x20 [ 48.016650] panic+0x2ad/0x55c [ 48.019830] ? add_taint.cold.5+0x16/0x16 [ 48.024000] ? __warn.cold.8+0x5/0x45 [ 48.027813] ? __warn+0xe8/0x1d0 [ 48.031178] ? __might_sleep+0x13d/0x190 [ 48.035220] __warn.cold.8+0x20/0x45 [ 48.038919] ? rcu_softirq_qs+0x20/0x20 [ 48.042887] ? __might_sleep+0x13d/0x190 [ 48.046941] report_bug+0x254/0x2d0 [ 48.050556] do_error_trap+0x11b/0x200 [ 48.054436] do_invalid_op+0x36/0x40 [ 48.058133] ? __might_sleep+0x13d/0x190 [ 48.062178] invalid_op+0x14/0x20 [ 48.065616] RIP: 0010:__might_sleep+0x13d/0x190 [ 48.070269] Code: 65 48 8b 1c 25 40 ee 01 00 48 8d 7b 10 48 89 fe 48 c1 ee 03 80 3c 06 00 75 2b 48 8b 73 10 48 c7 c7 40 e0 2a 88 e8 43 27 f3 ff <0f> 0b e9 43 ff ff ff e8 f7 7c 6c 00 e9 26 ff ff ff e8 ed 7c 6c 00 [ 48.089155] RSP: 0018:ffff8881b141f8f8 EFLAGS: 00010286 [ 48.094498] RAX: 0000000000000000 RBX: ffff8881c1230140 RCX: 0000000000000000 [ 48.101753] RDX: 0000000000000000 RSI: ffffffff8164e045 RDI: 0000000000000005 [ 48.109008] RBP: ffff8881b141f928 R08: ffff8881c1230140 R09: 0000000000000007 [ 48.116263] R10: 0000000000000000 R11: ffff8881c1230140 R12: ffffffff8860b220 [ 48.123516] R13: 0000000000000019 R14: 0000000000000000 R15: ffff8881c1230140 [ 48.130779] ? vprintk_func+0x85/0x181 [ 48.134651] ? __might_sleep+0x13d/0x190 [ 48.138702] __might_fault+0xc6/0x1e0 [ 48.142487] _copy_to_user+0x30/0x110 [ 48.146277] n_hdlc_tty_read+0x5c1/0x7f0 [ 48.150325] ? n_hdlc_tty_poll+0x5f0/0x5f0 [ 48.154552] ? wake_up_q+0x100/0x100 [ 48.158255] ? ldsem_down_read+0x32/0x40 [ 48.162300] ? ldsem_down_read+0x32/0x40 [ 48.166348] tty_read+0x194/0x2a0 [ 48.169840] ? n_hdlc_tty_poll+0x5f0/0x5f0 [ 48.174060] __vfs_read+0x117/0x9b0 [ 48.177673] ? debug_lockdep_rcu_enabled+0x77/0x90 [ 48.182603] ? tty_poll+0x1a0/0x1a0 [ 48.186218] ? vfs_copy_file_range+0xb90/0xb90 [ 48.190783] ? apparmor_path_rmdir+0x30/0x30 [ 48.195175] ? rcu_softirq_qs+0x20/0x20 [ 48.199141] ? apparmor_file_permission+0x24/0x30 [ 48.203969] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 48.209490] ? security_file_permission+0x1c2/0x230 [ 48.214490] ? rw_verify_area+0x118/0x360 [ 48.218624] vfs_read+0x17f/0x3c0 [ 48.222066] ksys_read+0x101/0x260 [ 48.225596] ? kernel_write+0x120/0x120 [ 48.229559] ? __bpf_trace_preemptirq_template+0x30/0x30 [ 48.234994] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 48.240518] __ia32_sys_read+0x71/0xb0 [ 48.244392] do_fast_syscall_32+0x34d/0xfb2 [ 48.248699] ? do_int80_syscall_32+0x890/0x890 [ 48.253267] ? entry_SYSENTER_compat+0x68/0x7f [ 48.257837] ? trace_hardirqs_off_caller+0xbb/0x310 [ 48.262836] ? syscall_return_slowpath+0x5e0/0x5e0 [ 48.267748] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 48.272574] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 48.277403] ? trace_hardirqs_on_caller+0x310/0x310 [ 48.282409] ? prepare_exit_to_usermode+0x3b0/0x3b0 [ 48.287418] ? prepare_exit_to_usermode+0x291/0x3b0 [ 48.292438] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 48.297269] entry_SYSENTER_compat+0x70/0x7f [ 48.301659] RIP: 0023:0xf7f00a49 [ 48.305011] Code: 85 d2 74 02 89 0a 5b 5d c3 8b 04 24 c3 8b 14 24 c3 8b 3c 24 c3 90 90 90 90 90 90 90 90 90 90 90 90 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 eb 0d 90 90 90 90 90 90 90 90 90 90 90 90 [ 48.323898] RSP: 002b:00000000ffac2a7c EFLAGS: 00000282 ORIG_RAX: 0000000000000003 [ 48.331591] RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000020000080 [ 48.338845] RDX: 0000000000000057 RSI: 00000000080ea080 RDI: 00000000ffac2ad0 [ 48.346097] RBP: 0000000000001000 R08: 0000000000000000 R09: 0000000000000000 [ 48.353347] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 [ 48.360598] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 [ 48.369012] Kernel Offset: disabled [ 48.372687] Rebooting in 86400 seconds..