[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[ 23.634228] random: sshd: uninitialized urandom read (32 bytes read) [?25l[?1c7[ ok 8[?25h[?0c. [ 23.967591] random: sshd: uninitialized urandom read (32 bytes read) [ 24.293526] random: sshd: uninitialized urandom read (32 bytes read) [ 24.855471] random: sshd: uninitialized urandom read (32 bytes read) Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 25.040561] random: sshd: uninitialized urandom read (32 bytes read) Warning: Permanently added '10.128.15.213' (ECDSA) to the list of known hosts. [ 30.711090] random: sshd: uninitialized urandom read (32 bytes read) executing program [ 30.838080] [ 30.839803] ============================= [ 30.843964] WARNING: suspicious RCU usage [ 30.848113] 4.19.0-rc1+ #44 Not tainted [ 30.852088] ----------------------------- [ 30.856249] include/linux/rcupdate.h:631 rcu_read_lock() used illegally while idle! [ 30.864043] [ 30.864043] other info that might help us debug this: [ 30.864043] [ 30.872220] [ 30.872220] RCU used illegally from idle CPU! [ 30.872220] rcu_scheduler_active = 2, debug_locks = 1 [ 30.883243] RCU used illegally from extended quiescent state! [ 30.889133] 1 lock held by swapper/0/0: [ 30.893106] #0: 000000004b34587c (rcu_read_lock){....}, at: trace_call_bpf+0xf8/0x640 [ 30.901206] [ 30.901206] stack backtrace: [ 30.905717] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.19.0-rc1+ #44 [ 30.912296] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 30.921652] Call Trace: [ 30.924253] dump_stack+0x1c9/0x2b4 [ 30.927898] ? dump_stack_print_info.cold.2+0x52/0x52 [ 30.933110] ? vprintk_func+0x81/0x117 [ 30.937016] lockdep_rcu_suspicious+0x14a/0x153 [ 30.941704] trace_call_bpf+0x533/0x640 [ 30.945690] ? mark_held_locks+0x160/0x160 [ 30.949943] ? kprobe_prog_is_valid_access+0xa0/0xa0 [ 30.955084] ? mark_held_locks+0x160/0x160 [ 30.959354] ? find_held_lock+0x36/0x1c0 [ 30.963434] perf_trace_run_bpf_submit+0x15c/0x3b0 [ 30.968382] ? perf_tp_event+0xc40/0xc40 [ 30.972464] ? graph_lock+0x170/0x170 [ 30.976295] ? graph_lock+0x170/0x170 [ 30.980118] ? memset+0x31/0x40 [ 30.983419] perf_trace_preemptirq_template+0x3dd/0x650 [ 30.988802] ? retint_kernel+0x10/0x10 [ 30.992726] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 30.997493] ? tracing_start_sched_switch.cold.0+0x78/0x78 [ 31.003133] ? lock_downgrade+0x8f0/0x8f0 [ 31.007302] ? trace_hardirqs_off+0xb8/0x2b0 [ 31.011735] ? rcu_seq_end+0x120/0x120 [ 31.015644] ? perf_trace_preemptirq_template+0x3f9/0x650 [ 31.021216] ? trace_hardirqs_on+0x2c0/0x2c0 [ 31.025634] ? arch_cpu_idle+0x10/0x20 [ 31.029533] ? default_idle+0x8d/0x410 [ 31.033432] ? retint_kernel+0x10/0x10 [ 31.037334] ? tracing_start_sched_switch.cold.0+0x78/0x78 [ 31.042968] trace_hardirqs_on_caller+0x227/0x2b0 [ 31.047841] ? timekeeping_max_deferment+0x20a/0x330 [ 31.052984] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 31.055598] [ 31.057752] ? __bpf_trace_preemptirq_template+0x30/0x30 [ 31.059375] ============================= [ 31.064833] ? timekeeping_valid_for_hres+0x340/0x340 [ 31.068957] WARNING: suspicious RCU usage [ 31.074151] trace_hardirqs_on_thunk+0x1a/0x1c [ 31.078271] 4.19.0-rc1+ #44 Not tainted [ 31.082861] ? rcu_dynticks_eqs_enter+0x22/0x30 [ 31.086821] ----------------------------- [ 31.091488] retint_kernel+0x10/0x10 [ 31.095621] kernel/trace/bpf_trace.c:72 suspicious rcu_dereference_check() usage! [ 31.099325] RIP: 0010:native_safe_halt+0x6/0x10 [ 31.106923] [ 31.106923] other info that might help us debug this: [ 31.106923] [ 31.111601] Code: c7 48 89 45 d8 e8 ba 60 e7 fa 48 8b 45 d8 e9 d2 fe ff ff 48 89 df e8 a9 60 e7 fa eb 8a 90 90 90 90 90 90 90 55 48 89 e5 fb f4 <5d> c3 0f 1f 84 00 00 00 00 00 55 48 89 e5 f4 5d c3 90 90 90 90 90 [ 31.119726] [ 31.119726] RCU used illegally from idle CPU! [ 31.119726] rcu_scheduler_active = 2, debug_locks = 1 [ 31.138627] RSP: 0018:ffffffff88007bb8 EFLAGS: 00000286 [ 31.149609] RCU used illegally from extended quiescent state! [ 31.149622] ORIG_RAX: ffffffffffffff13 [ 31.154970] 1 lock held by swapper/1/0: [ 31.160845] RAX: dffffc0000000000 RBX: 1ffffffff1000f7b RCX: 0000000000000000 [ 31.164799] #0: [ 31.168775] RDX: 1ffffffff10237b8 RSI: 0000000000000001 RDI: ffffffff8811bdc0 [ 31.176032] 000000004b34587c [ 31.178099] RBP: ffffffff88007bb8 R08: ffffffff88075e00 R09: 0000000000000000 [ 31.185360] ( [ 31.188371] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 [ 31.195648] rcu_read_lock [ 31.197445] R13: ffffffff88007c78 R14: 0000000000000000 R15: 0000000000000000 [ 31.204703] ){....} [ 31.207494] default_idle+0xc2/0x410 [ 31.214737] , at: trace_call_bpf+0xf8/0x640 [ 31.216967] ? kasan_check_write+0x14/0x20 [ 31.220661] [ 31.220661] stack backtrace: [ 31.224979] ? __sched_text_end+0x1/0x1 [ 31.237674] ? rcu_idle_enter+0x30a/0x480 [ 31.241832] ? rcu_eqs_special_set+0x1b0/0x1b0 [ 31.246422] ? tsc_verify_tsc_adjust+0x109/0x380 [ 31.251185] ? trace_hardirqs_off_caller+0x2b0/0x2b0 [ 31.256295] ? mark_tsc_async_resets+0x20/0x20 [ 31.260877] ? trace_hardirqs_on+0x2c0/0x2c0 [ 31.265290] ? __tick_nohz_idle_restart_tick+0x28c/0x3c0 [ 31.270748] arch_cpu_idle+0x10/0x20 [ 31.274465] default_idle_call+0x6d/0x90 [ 31.278532] do_idle+0x3aa/0x580 [ 31.281902] ? retint_kernel+0x10/0x10 [ 31.285796] ? arch_cpu_idle_exit+0x70/0x70 [ 31.290143] cpu_startup_entry+0x10c/0x120 [ 31.294380] ? cpu_in_idle+0x20/0x20 [ 31.298123] rest_init+0xe1/0xe4 [ 31.301504] start_kernel+0x913/0x94e [ 31.305305] ? mem_encrypt_init+0xb/0xb [ 31.309285] ? early_idt_handler_common+0x3b/0x60 [ 31.314143] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 31.319679] ? x86_family+0x3e/0x50 [ 31.323314] ? __sanitizer_cov_trace_const_cmp1+0x1a/0x20 [ 31.328859] x86_64_start_reservations+0x29/0x2b [ 31.333617] x86_64_start_kernel+0x76/0x79 [ 31.337870] secondary_startup_64+0xa4/0xb0 [ 31.342206] [ 31.342218] CPU: 1 PID: 0 Comm: swapper/1 Not tainted 4.19.0-rc1+ #44 [ 31.342254] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 31.343874] ============================= [ 31.343883] WARNING: suspicious RCU usage [ 31.350459] Call Trace: [ 31.359837] 4.19.0-rc1+ #44 Not tainted [ 31.363984] dump_stack+0x1c9/0x2b4 [ 31.368103] ----------------------------- [ 31.370688] ? dump_stack_print_info.cold.2+0x52/0x52 [ 31.374634] include/linux/rcupdate.h:680 rcu_read_unlock() used illegally while idle! [ 31.374643] [ 31.374643] other info that might help us debug this: [ 31.374643] [ 31.378271] ? vprintk_func+0x81/0x117 [ 31.382416] [ 31.382416] RCU used illegally from idle CPU! [ 31.382416] rcu_scheduler_active = 2, debug_locks = 1 [ 31.387602] lockdep_rcu_suspicious+0x14a/0x153 [ 31.395555] RCU used illegally from extended quiescent state! [ 31.403699] trace_call_bpf+0x4cb/0x640 [ 31.407586] 1 lock held by swapper/0/0: [ 31.418602] ? kprobe_prog_is_valid_access+0xa0/0xa0 [ 31.423263] #0: [ 31.429145] ? rcu_cleanup_dead_rnp+0x200/0x200 [ 31.433095] 000000004b34587c [ 31.437070] ? trace_call_bpf+0x418/0x640 [ 31.442150] ( [ 31.444228] perf_trace_run_bpf_submit+0x15c/0x3b0 [ 31.448865] rcu_read_lock [ 31.451908] ? perf_tp_event+0xc40/0xc40 [ 31.456028] ){....} [ 31.457837] ? _raw_spin_unlock_irq+0x27/0x70 [ 31.462761] , at: trace_call_bpf+0xf8/0x640 [ 31.465506] ? _raw_spin_unlock_irq+0x27/0x70 [ 31.469541] [ 31.469541] stack backtrace: [ 31.471802] ? memset+0x31/0x40 [ 31.492870] perf_trace_preemptirq_template+0x3dd/0x650 [ 31.498243] ? arch_cpu_idle+0x10/0x20 [ 31.502127] ? default_idle+0x8d/0x410 [ 31.506015] ? tracing_start_sched_switch.cold.0+0x78/0x78 [ 31.511640] ? trace_hardirqs_off+0xb8/0x2b0 [ 31.516059] ? memset+0x31/0x40 [ 31.519344] ? trace_hardirqs_on+0x2c0/0x2c0 [ 31.523763] ? rcu_seq_end+0x120/0x120 [ 31.527652] ? __sanitizer_cov_trace_const_cmp1+0x1a/0x20 [ 31.533202] ? tick_nohz_next_event+0x493/0x8a0 [ 31.537881] ? tracing_start_sched_switch.cold.0+0x78/0x78 [ 31.543521] ? default_idle+0x8d/0x410 [ 31.547406] ? tracing_start_sched_switch.cold.0+0x78/0x78 [ 31.553033] trace_hardirqs_on+0x22e/0x2c0 [ 31.557272] ? arch_cpu_idle+0x10/0x20 [ 31.561163] ? trace_hardirqs_off_caller+0x2b0/0x2b0 [ 31.566305] ? __sanitizer_cov_trace_const_cmp2+0x18/0x20 [ 31.571869] default_idle+0x8d/0x410 [ 31.575595] ? kasan_check_write+0x14/0x20 [ 31.579838] ? __sched_text_end+0x1/0x1 [ 31.583832] ? rcu_idle_enter+0x30a/0x480 [ 31.587988] ? rcu_eqs_special_set+0x1b0/0x1b0 [ 31.592577] ? tsc_verify_tsc_adjust+0x109/0x380 [ 31.597338] ? trace_hardirqs_off_caller+0x2b0/0x2b0 [ 31.602443] ? mark_tsc_async_resets+0x20/0x20 [ 31.607022] ? trace_hardirqs_on+0x2c0/0x2c0 [ 31.611434] ? __tick_nohz_idle_restart_tick+0x28c/0x3c0 [ 31.616905] arch_cpu_idle+0x10/0x20 [ 31.620622] default_idle_call+0x6d/0x90 [ 31.624689] do_idle+0x3aa/0x580 [ 31.628070] ? kasan_check_write+0x14/0x20 [ 31.632317] ? arch_cpu_idle_exit+0x70/0x70 [ 31.636641] ? complete+0x62/0x80 [ 31.640103] cpu_startup_entry+0x10c/0x120 [ 31.644341] ? cpu_in_idle+0x20/0x20 [ 31.648070] start_secondary+0x433/0x5d0 [ 31.652135] ? set_cpu_sibling_map+0x18b0/0x18b0 [ 31.656916] secondary_startup_64+0xa4/0xb0 [ 31.661265] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.19.0-rc1+ #44 [ 31.667853] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 31.677400] Call Trace: [ 31.680000] dump_stack+0x1c9/0x2b4 [ 31.683646] ? dump_stack_print_info.cold.2+0x52/0x52 [ 31.688859] ? vprintk_func+0x81/0x117 [ 31.692750] lockdep_rcu_suspicious+0x14a/0x153 [ 31.697406] trace_call_bpf+0x579/0x640 [ 31.701368] ? kprobe_prog_is_valid_access+0xa0/0xa0 [ 31.706460] ? find_held_lock+0x36/0x1c0 [ 31.710506] perf_trace_run_bpf_submit+0x15c/0x3b0 [ 31.715431] ? perf_tp_event+0xc40/0xc40 [ 31.719503] ? graph_lock+0x170/0x170 [ 31.723281] ? graph_lock+0x170/0x170 [ 31.727065] ? memset+0x31/0x40 [ 31.730356] perf_trace_preemptirq_template+0x3dd/0x650 [ 31.735708] ? retint_kernel+0x10/0x10 [ 31.739577] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 31.744329] ? tracing_start_sched_switch.cold.0+0x78/0x78 [ 31.749950] ? lock_downgrade+0x8f0/0x8f0 [ 31.754092] ? trace_hardirqs_off+0xb8/0x2b0 [ 31.758523] ? rcu_seq_end+0x120/0x120 [ 31.762392] ? perf_trace_preemptirq_template+0x3f9/0x650 [ 31.767927] ? trace_hardirqs_on+0x2c0/0x2c0 [ 31.772320] ? arch_cpu_idle+0x10/0x20 [ 31.776191] ? default_idle+0x8d/0x410 [ 31.780089] ? retint_kernel+0x10/0x10 [ 31.783963] ? tracing_start_sched_switch.cold.0+0x78/0x78 [ 31.789593] trace_hardirqs_on_caller+0x227/0x2b0 [ 31.794421] ? timekeeping_max_deferment+0x20a/0x330 [ 31.799527] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 31.804285] ? __bpf_trace_preemptirq_template+0x30/0x30 [ 31.809716] ? timekeeping_valid_for_hres+0x340/0x340 [ 31.814897] trace_hardirqs_on_thunk+0x1a/0x1c [ 31.819466] ? rcu_dynticks_eqs_enter+0x22/0x30 [ 31.824148] retint_kernel+0x10/0x10 [ 31.827844] RIP: 0010:native_safe_halt+0x6/0x10 [ 31.832511] Code: c7 48 89 45 d8 e8 ba 60 e7 fa 48 8b 45 d8 e9 d2 fe ff ff 48 89 df e8 a9 60 e7 fa eb 8a 90 90 90 90 90 90 90 55 48 89 e5 fb f4 <5d> c3 0f 1f 84 00 00 00 00 00 55 48 89 e5 f4 5d c3 90 90 90 90 90 [ 31.851397] RSP: 0018:ffffffff88007bb8 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff13 [ 31.859091] RAX: dffffc0000000000 RBX: 1ffffffff1000f7b RCX: 0000000000000000 [ 31.866338] RDX: 1ffffffff10237b8 RSI: 0000000000000001 RDI: ffffffff8811bdc0 [ 31.873590] RBP: ffffffff88007bb8 R08: ffffffff88075e00 R09: 0000000000000000 [ 31.880842] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 [ 31.888109] R13: ffffffff88007c78 R14: 0000000000000000 R15: 0000000000000000 [ 31.895393] default_idle+0xc2/0x410 [ 31.899140] ? kasan_check_write+0x14/0x20 [ 31.903356] ? __sched_text_end+0x1/0x1 [ 31.907312] ? rcu_idle_enter+0x30a/0x480 [ 31.911451] ? rcu_eqs_special_set+0x1b0/0x1b0 [ 31.916021] ? tsc_verify_tsc_adjust+0x109/0x380 [ 31.920774] ? trace_hardirqs_off_caller+0x2b0/0x2b0 [ 31.925862] ? mark_tsc_async_resets+0x20/0x20 [ 31.930428] ? trace_hardirqs_on+0x2c0/0x2c0 [ 31.934836] ? __tick_nohz_idle_restart_tick+0x28c/0x3c0 [ 31.940276] arch_cpu_idle+0x10/0x20 [ 31.943974] default_idle_call+0x6d/0x90 [ 31.948045] do_idle+0x3aa/0x580 [ 31.951402] ? retint_kernel+0x10/0x10 [ 31.955289] ? arch_cpu_idle_exit+0x70/0x70 [ 31.959615] cpu_startup_entry+0x10c/0x120 [ 31.963834] ? cpu_in_idle+0x20/0x20 [ 31.967534] rest_init+0xe1/0xe4 [ 31.970882] start_kernel+0x913/0x94e [ 31.974666] ? mem_encrypt_init+0xb/0xb [ 31.978626] ? early_idt_handler_common+0x3b/0x60 [ 31.983463] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 31.988984] ? x86_family+0x3e/0x50 [ 31.992593] ? __sanitizer_cov_trace_const_cmp1+0x1a/0x20 [ 31.998138] x86_64_start_reservations+0x29/0x2b [ 32.002883] x86_64_start_kernel+0x76/0x79 [ 32.007100] secondary_startup_64+0xa4/0xb0