[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[ 22.383080] random: sshd: uninitialized urandom read (32 bytes read) [?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 25.906475] random: sshd: uninitialized urandom read (32 bytes read) [ 26.216341] random: sshd: uninitialized urandom read (32 bytes read) [ 26.802502] random: sshd: uninitialized urandom read (32 bytes read) [ 26.983854] random: sshd: uninitialized urandom read (32 bytes read) Warning: Permanently added '10.128.10.50' (ECDSA) to the list of known hosts. [ 32.580123] random: sshd: uninitialized urandom read (32 bytes read) [ 32.683430] IPVS: ftp: loaded support on port[0] = 21 [ 32.722771] [ 32.723661] [ 32.724473] ============================= [ 32.726103] ============================= [ 32.730237] WARNING: suspicious RCU usage [ 32.734370] WARNING: suspicious RCU usage [ 32.738514] 4.19.0-rc1+ #218 Not tainted [ 32.742644] 4.19.0-rc1+ #218 Not tainted [ 32.746683] ----------------------------- [ 32.750726] ----------------------------- [ 32.754868] include/linux/rcupdate.h:631 rcu_read_lock() used illegally while idle! [ 32.758998] kernel/trace/bpf_trace.c:72 suspicious rcu_dereference_check() usage! [ 32.766786] [ 32.766786] other info that might help us debug this: [ 32.766786] [ 32.774438] [ 32.774438] other info that might help us debug this: [ 32.774438] [ 32.782577] [ 32.782577] RCU used illegally from idle CPU! [ 32.782577] rcu_scheduler_active = 2, debug_locks = 1 [ 32.790710] [ 32.790710] RCU used illegally from idle CPU! [ 32.790710] rcu_scheduler_active = 2, debug_locks = 1 [ 32.801705] RCU used illegally from extended quiescent state! [ 32.812694] RCU used illegally from extended quiescent state! [ 32.818565] 1 lock held by swapper/1/0: [ 32.824430] 1 lock held by swapper/0/0: [ 32.828383] #0: [ 32.832335] #0: [ 32.832348] 00000000c56a0d6a [ 32.834392] 00000000c56a0d6a [ 32.836437] ( [ 32.839439] ( [ 32.842451] rcu_read_lock [ 32.844237] rcu_read_lock [ 32.846026] ){....} [ 32.848778] ){....} [ 32.851533] , at: trace_call_bpf+0xf8/0x640 [ 32.853764] , at: trace_call_bpf+0xf8/0x640 [ 32.855969] [ 32.855969] stack backtrace: [ 32.860273] [ 32.860273] stack backtrace: [ 32.864593] CPU: 1 PID: 0 Comm: swapper/1 Not tainted 4.19.0-rc1+ #218 [ 32.880208] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 32.889560] Call Trace: [ 32.892159] dump_stack+0x1c9/0x2b4 [ 32.895800] ? dump_stack_print_info.cold.2+0x52/0x52 [ 32.901001] ? vprintk_func+0x81/0x117 [ 32.904894] lockdep_rcu_suspicious+0x14a/0x153 [ 32.909567] trace_call_bpf+0x533/0x640 [ 32.913549] ? kprobe_prog_is_valid_access+0xa0/0xa0 [ 32.918658] ? rcu_cleanup_dead_rnp+0x200/0x200 [ 32.923338] ? trace_call_bpf+0x418/0x640 [ 32.927502] perf_trace_run_bpf_submit+0x15c/0x3b0 [ 32.932439] ? perf_tp_event+0xc40/0xc40 [ 32.936498] ? _raw_spin_unlock_irq+0x27/0x70 [ 32.940996] ? _raw_spin_unlock_irq+0x27/0x70 [ 32.945504] ? memset+0x31/0x40 [ 32.948792] perf_trace_preemptirq_template+0x3dd/0x650 [ 32.954174] ? arch_cpu_idle+0x10/0x20 [ 32.958062] ? default_idle+0x8d/0x410 [ 32.961954] ? tracing_start_sched_switch.cold.0+0x78/0x78 [ 32.967583] ? trace_hardirqs_off+0xb8/0x2b0 [ 32.971999] ? memset+0x31/0x40 [ 32.975286] ? trace_hardirqs_on+0x2c0/0x2c0 [ 32.979706] ? rcu_seq_end+0x120/0x120 [ 32.983597] ? __sanitizer_cov_trace_const_cmp1+0x1a/0x20 [ 32.989134] ? tick_nohz_next_event+0x493/0x8a0 [ 32.993809] ? tracing_start_sched_switch.cold.0+0x78/0x78 [ 32.999481] ? default_idle+0x8d/0x410 [ 33.003369] ? tracing_start_sched_switch.cold.0+0x78/0x78 [ 33.008994] trace_hardirqs_on+0x22e/0x2c0 [ 33.013232] ? arch_cpu_idle+0x10/0x20 [ 33.017128] ? trace_hardirqs_off_caller+0x2b0/0x2b0 [ 33.022240] ? __sanitizer_cov_trace_const_cmp2+0x18/0x20 [ 33.027790] default_idle+0x8d/0x410 [ 33.031512] ? kasan_check_write+0x14/0x20 [ 33.035762] ? __sched_text_end+0x1/0x1 [ 33.039752] ? rcu_idle_enter+0x30a/0x480 [ 33.043915] ? rcu_eqs_special_set+0x1b0/0x1b0 [ 33.048501] ? tsc_verify_tsc_adjust+0x109/0x380 [ 33.053266] ? trace_hardirqs_off_caller+0x2b0/0x2b0 [ 33.058375] ? mark_tsc_async_resets+0x20/0x20 [ 33.062964] ? trace_hardirqs_on+0x2c0/0x2c0 [ 33.067375] ? update_ts_time_stats+0xb3/0x1e0 [ 33.071964] arch_cpu_idle+0x10/0x20 [ 33.075681] default_idle_call+0x6d/0x90 [ 33.079753] do_idle+0x3aa/0x580 [ 33.083124] ? kasan_check_write+0x14/0x20 [ 33.087367] ? arch_cpu_idle_exit+0x70/0x70 [ 33.091697] ? complete+0x62/0x80 [ 33.095162] cpu_startup_entry+0x10c/0x120 [ 33.099402] ? cpu_in_idle+0x20/0x20 [ 33.103131] start_secondary+0x433/0x5d0 [ 33.107200] ? set_cpu_sibling_map+0x18b0/0x18b0 [ 33.111972] secondary_startup_64+0xa4/0xb0 [ 33.116306] [ 33.116320] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.19.0-rc1+ #218 [ 33.116333] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 33.117947] ============================= [ 33.117957] WARNING: suspicious RCU usage [ 33.124626] Call Trace: [ 33.133983] 4.19.0-rc1+ #218 Not tainted [ 33.138179] dump_stack+0x1c9/0x2b4 [ 33.142299] ----------------------------- [ 33.144896] ? dump_stack_print_info.cold.2+0x52/0x52 [ 33.148928] include/linux/rcupdate.h:680 rcu_read_unlock() used illegally while idle! [ 33.152553] ? vprintk_func+0x81/0x117 [ 33.156689] [ 33.156689] other info that might help us debug this: [ 33.156689] [ 33.161881] lockdep_rcu_suspicious+0x14a/0x153 [ 33.169827] [ 33.169827] RCU used illegally from idle CPU! [ 33.169827] rcu_scheduler_active = 2, debug_locks = 1 [ 33.173719] trace_call_bpf+0x4cb/0x640 [ 33.181839] RCU used illegally from extended quiescent state! [ 33.186522] ? mark_held_locks+0x160/0x160 [ 33.197510] 1 lock held by swapper/1/0: [ 33.201487] ? kprobe_prog_is_valid_access+0xa0/0xa0 [ 33.207338] #0: [ 33.211583] ? find_held_lock+0x36/0x1c0 [ 33.215516] 00000000c56a0d6a [ 33.220614] perf_trace_run_bpf_submit+0x15c/0x3b0 [ 33.222642] ( [ 33.226699] ? perf_tp_event+0xc40/0xc40 [ 33.229687] rcu_read_lock [ 33.234607] ? graph_lock+0x170/0x170 [ 33.236385] ){....} [ 33.240437] ? graph_lock+0x170/0x170 [ 33.243178] , at: trace_call_bpf+0xf8/0x640 [ 33.246966] ? memset+0x31/0x40 [ 33.249177] [ 33.249177] stack backtrace: [ 33.252979] perf_trace_preemptirq_template+0x3dd/0x650 [ 33.270379] ? retint_kernel+0x10/0x10 [ 33.274269] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 33.279031] ? tracing_start_sched_switch.cold.0+0x78/0x78 [ 33.284658] ? lock_downgrade+0x8f0/0x8f0 [ 33.288815] ? trace_hardirqs_off+0xb8/0x2b0 [ 33.293226] ? rcu_seq_end+0x120/0x120 [ 33.297115] ? perf_trace_preemptirq_template+0x3f9/0x650 [ 33.302651] ? trace_hardirqs_on+0x2c0/0x2c0 [ 33.307057] ? arch_cpu_idle+0x10/0x20 [ 33.310944] ? default_idle+0x8d/0x410 [ 33.314834] ? retint_kernel+0x10/0x10 [ 33.318725] ? tracing_start_sched_switch.cold.0+0x78/0x78 [ 33.324362] trace_hardirqs_on_caller+0x227/0x2b0 [ 33.329212] ? timekeeping_max_deferment+0x20a/0x330 [ 33.334317] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 33.339076] ? __bpf_trace_preemptirq_template+0x30/0x30 [ 33.344530] ? timekeeping_valid_for_hres+0x340/0x340 [ 33.349736] trace_hardirqs_on_thunk+0x1a/0x1c [ 33.354336] ? rcu_dynticks_eqs_enter+0x22/0x30 [ 33.359008] retint_kernel+0x10/0x10 [ 33.362719] RIP: 0010:native_safe_halt+0x6/0x10 [ 33.367402] Code: c7 48 89 45 d8 e8 ca 39 e7 fa 48 8b 45 d8 e9 d2 fe ff ff 48 89 df e8 b9 39 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 [ 33.386302] RSP: 0018:ffffffff88007bb8 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff13 [ 33.394667] RAX: dffffc0000000000 RBX: 1ffffffff1000f7b RCX: 0000000000000000 [ 33.401940] RDX: 1ffffffff10237b8 RSI: 0000000000000001 RDI: ffffffff8811bdc0 [ 33.409207] RBP: ffffffff88007bb8 R08: ffffffff88075e00 R09: 0000000000000000 [ 33.416472] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 [ 33.423739] R13: ffffffff88007c78 R14: 0000000000000000 R15: 0000000000000000 [ 33.431060] default_idle+0xc2/0x410 [ 33.434785] ? kasan_check_write+0x14/0x20 [ 33.439021] ? __sched_text_end+0x1/0x1 [ 33.443000] ? rcu_idle_enter+0x30a/0x480 [ 33.447147] ? rcu_eqs_special_set+0x1b0/0x1b0 [ 33.451730] ? tsc_verify_tsc_adjust+0x109/0x380 [ 33.456497] ? trace_hardirqs_off_caller+0x2b0/0x2b0 [ 33.461602] ? mark_tsc_async_resets+0x20/0x20 [ 33.466181] ? trace_hardirqs_on+0x2c0/0x2c0 [ 33.470591] ? __tick_nohz_idle_restart_tick+0x28c/0x3c0 [ 33.476053] arch_cpu_idle+0x10/0x20 [ 33.479780] default_idle_call+0x6d/0x90 [ 33.483848] do_idle+0x3aa/0x580 [ 33.487224] ? arch_cpu_idle_exit+0x70/0x70 [ 33.491548] ? __schedule+0x1df0/0x1df0 [ 33.495535] cpu_startup_entry+0x10c/0x120 [ 33.499783] ? cpu_in_idle+0x20/0x20 [ 33.503513] rest_init+0xe1/0xe4 [ 33.506887] start_kernel+0x913/0x94e [ 33.510687] ? mem_encrypt_init+0xb/0xb [ 33.514665] ? early_idt_handler_common+0x3b/0x60 [ 33.519521] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 33.525055] ? x86_family+0x3e/0x50 [ 33.528685] ? __sanitizer_cov_trace_const_cmp1+0x1a/0x20 [ 33.534233] x86_64_start_reservations+0x29/0x2b [ 33.538994] x86_64_start_kernel+0x76/0x79 [ 33.543234] secondary_startup_64+0xa4/0xb0 [ 33.547574] CPU: 1 PID: 0 Comm: swapper/1 Not tainted 4.19.0-rc1+ #218 [ 33.554239] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 33.563573] Call Trace: [ 33.566146] dump_stack+0x1c9/0x2b4 [ 33.569765] ? dump_stack_print_info.cold.2+0x52/0x52 [ 33.574946] ? vprintk_func+0x81/0x117 [ 33.578820] lockdep_rcu_suspicious+0x14a/0x153 [ 33.583472] trace_call_bpf+0x579/0x640 [ 33.587428] ? kprobe_prog_is_valid_access+0xa0/0xa0 [ 33.592515] ? rcu_cleanup_dead_rnp+0x200/0x200 [ 33.597207] ? trace_call_bpf+0x418/0x640 [ 33.601342] perf_trace_run_bpf_submit+0x15c/0x3b0 [ 33.606260] ? perf_tp_event+0xc40/0xc40 [ 33.610303] ? _raw_spin_unlock_irq+0x27/0x70 [ 33.614779] ? _raw_spin_unlock_irq+0x27/0x70 [ 33.619265] ? memset+0x31/0x40 [ 33.622527] perf_trace_preemptirq_template+0x3dd/0x650 [ 33.627872] ? arch_cpu_idle+0x10/0x20 [ 33.631737] ? default_idle+0x8d/0x410 [ 33.635615] ? tracing_start_sched_switch.cold.0+0x78/0x78 [ 33.641222] ? trace_hardirqs_off+0xb8/0x2b0 [ 33.645613] ? memset+0x31/0x40 [ 33.648873] ? trace_hardirqs_on+0x2c0/0x2c0 [ 33.653271] ? rcu_seq_end+0x120/0x120 [ 33.657142] ? __sanitizer_cov_trace_const_cmp1+0x1a/0x20 [ 33.662662] ? tick_nohz_next_event+0x493/0x8a0 [ 33.667310] ? tracing_start_sched_switch.cold.0+0x78/0x78 [ 33.672921] ? default_idle+0x8d/0x410 [ 33.676789] ? tracing_start_sched_switch.cold.0+0x78/0x78 [ 33.682398] trace_hardirqs_on+0x22e/0x2c0 [ 33.686616] ? arch_cpu_idle+0x10/0x20 [ 33.690484] ? trace_hardirqs_off_caller+0x2b0/0x2b0 [ 33.695575] ? __sanitizer_cov_trace_const_cmp2+0x18/0x20 [ 33.701095] default_idle+0x8d/0x410 [ 33.704794] ? kasan_check_write+0x14/0x20 [ 33.709011] ? __sched_text_end+0x1/0x1 [ 33.712971] ? rcu_idle_enter+0x30a/0x480 [ 33.717105] ? rcu_eqs_special_set+0x1b0/0x1b0 [ 33.721673] ? tsc_verify_tsc_adjust+0x109/0x380 [ 33.726410] ? trace_hardirqs_off_caller+0x2b0/0x2b0 [ 33.731530] ? mark_tsc_async_resets+0x20/0x20 [ 33.736091] ? trace_hardirqs_on+0x2c0/0x2c0 [ 33.740478] ? update_ts_time_stats+0xb3/0x1e0 [ 33.745043] arch_cpu_idle+0x10/0x20 [ 33.748740] default_idle_call+0x6d/0x90 [ 33.752794] do_idle+0x3aa/0x580 [ 33.756142] ? kasan_check_write+0x14/0x20 [ 33.760391] ? arch_cpu_idle_exit+0x70/0x70 [ 33.764697] ? complete+0x62/0x80 [ 33.768135] cpu_startup_entry+0x10c/0x120 [ 33.772352] ? cpu_in_idle+0x20/0x20 [ 33.776057] st