[....] 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. [ 84.667680][ T27] kauditd_printk_skb: 4 callbacks suppressed [ 84.667692][ T27] audit: type=1800 audit(1581065990.244:29): pid=9786 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="rc.local" dev="sda1" ino=2432 res=0 [ 84.694605][ T27] audit: type=1800 audit(1581065990.244:30): pid=9786 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="rmnologin" dev="sda1" ino=2423 res=0 Debian GNU/Linux 7 syzkaller ttyS0 Warning: Permanently added '10.128.0.68' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 96.328388][ T9942] IPVS: ftp: loaded support on port[0] = 21 [ 96.413350][ C1] [ 96.415697][ C1] ================================ [ 96.420792][ C1] WARNING: inconsistent lock state [ 96.425952][ C1] 5.5.0-syzkaller #0 Not tainted [ 96.430926][ C1] -------------------------------- [ 96.436058][ C1] inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage. [ 96.442896][ C1] swapper/1/0 [HC0[0]:SC1[1]:HE1:SE0] takes: [ 96.448985][ C1] ffff8880a44069c8 (&(&local->client_conns_lock)->rlock){+.?.}, at: rxrpc_put_client_conn+0x6ed/0xc90 [ 96.459936][ C1] {SOFTIRQ-ON-W} state was registered at: [ 96.465670][ C1] lock_acquire+0x190/0x410 [ 96.470316][ C1] _raw_spin_lock+0x2f/0x40 [ 96.474896][ C1] rxrpc_connect_call+0x358/0x4e30 [ 96.480089][ C1] rxrpc_new_client_call+0x9c0/0x1ad0 [ 96.485529][ C1] rxrpc_do_sendmsg+0xffa/0x1d5f [ 96.490534][ C1] rxrpc_sendmsg+0x4d6/0x5f0 [ 96.495193][ C1] sock_sendmsg+0xd7/0x130 [ 96.499688][ C1] ____sys_sendmsg+0x358/0x880 [ 96.504516][ C1] ___sys_sendmsg+0x100/0x170 [ 96.509256][ C1] __sys_sendmmsg+0x1bf/0x4d0 [ 96.513997][ C1] __x64_sys_sendmmsg+0x9d/0x100 [ 96.519537][ C1] do_syscall_64+0xfa/0x790 [ 96.524276][ C1] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 96.530233][ C1] irq event stamp: 175864 [ 96.534559][ C1] hardirqs last enabled at (175864): [] _raw_spin_unlock_irqrestore+0x66/0xe0 [ 96.545131][ C1] hardirqs last disabled at (175863): [] _raw_spin_lock_irqsave+0x6f/0xcd [ 96.555175][ C1] softirqs last enabled at (175788): [] _local_bh_enable+0x1c/0x30 [ 96.564689][ C1] softirqs last disabled at (175789): [] irq_exit+0x19b/0x1e0 [ 96.573747][ C1] [ 96.573747][ C1] other info that might help us debug this: [ 96.581881][ C1] Possible unsafe locking scenario: [ 96.581881][ C1] [ 96.589428][ C1] CPU0 [ 96.592746][ C1] ---- [ 96.596520][ C1] lock(&(&local->client_conns_lock)->rlock); [ 96.602760][ C1] [ 96.606209][ C1] lock(&(&local->client_conns_lock)->rlock); [ 96.612619][ C1] [ 96.612619][ C1] *** DEADLOCK *** [ 96.612619][ C1] [ 96.620880][ C1] 1 lock held by swapper/1/0: [ 96.625531][ C1] #0: ffffffff89bac140 (rcu_callback){....}, at: rcu_core+0x562/0x1390 [ 96.633899][ C1] [ 96.633899][ C1] stack backtrace: [ 96.639861][ C1] CPU: 1 PID: 0 Comm: swapper/1 Not tainted 5.5.0-syzkaller #0 [ 96.647387][ C1] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 96.657474][ C1] Call Trace: [ 96.660747][ C1] [ 96.663588][ C1] dump_stack+0x197/0x210 [ 96.667971][ C1] print_usage_bug.cold+0x327/0x378 [ 96.673192][ C1] mark_lock+0xbb4/0x1220 [ 96.677524][ C1] ? kfree+0x10a/0x2c0 [ 96.681614][ C1] ? check_usage_backwards+0x330/0x330 [ 96.687145][ C1] ? __nf_hook_entries_free+0x31/0x40 [ 96.692515][ C1] __lock_acquire+0x1e8e/0x4a00 [ 96.697362][ C1] ? find_held_lock+0x35/0x130 [ 96.702161][ C1] ? __kasan_check_read+0x11/0x20 [ 96.707284][ C1] ? mark_lock+0xc2/0x1220 [ 96.711736][ C1] ? mark_held_locks+0xf0/0xf0 [ 96.716497][ C1] ? _raw_spin_unlock_irqrestore+0x66/0xe0 [ 96.722308][ C1] lock_acquire+0x190/0x410 [ 96.726887][ C1] ? rxrpc_put_client_conn+0x6ed/0xc90 [ 96.732577][ C1] _raw_spin_lock+0x2f/0x40 [ 96.737083][ C1] ? rxrpc_put_client_conn+0x6ed/0xc90 [ 96.742593][ C1] rxrpc_put_client_conn+0x6ed/0xc90 [ 96.747874][ C1] ? rxrpc_rcu_destroy_call+0xbd/0x200 [ 96.753317][ C1] rxrpc_rcu_destroy_call+0xbd/0x200 [ 96.758603][ C1] rcu_core+0x5e1/0x1390 [ 96.762898][ C1] ? __rcu_read_unlock+0x700/0x700 [ 96.768008][ C1] ? rcu_read_lock_sched_held+0x9c/0xd0 [ 96.773553][ C1] ? rcu_read_lock_any_held.part.0+0x50/0x50 [ 96.779649][ C1] ? run_rebalance_domains+0x227/0x2d0 [ 96.785186][ C1] rcu_core_si+0x9/0x10 [ 96.789322][ C1] __do_softirq+0x262/0x98c [ 96.793837][ C1] ? sched_clock_cpu+0x1b/0x1b0 [ 96.798861][ C1] irq_exit+0x19b/0x1e0 [ 96.803002][ C1] smp_apic_timer_interrupt+0x1a3/0x610 [ 96.808559][ C1] apic_timer_interrupt+0xf/0x20 [ 96.813487][ C1] [ 96.816420][ C1] RIP: 0010:native_safe_halt+0xe/0x10 [ 96.821812][ C1] Code: 48 70 c7 f9 eb 8a cc cc cc cc cc cc e9 07 00 00 00 0f 00 2d 44 d3 5b 00 f4 c3 66 90 e9 07 00 00 00 0f 00 2d 34 d3 5b 00 fb f4 cc 55 48 89 e5 41 57 41 56 41 55 41 54 53 e8 7e 2f 76 f9 e8 19 [ 96.841417][ C1] RSP: 0018:ffffc90000d3fd68 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff13 [ 96.850049][ C1] RAX: 1ffffffff1367612 RBX: ffff8880a99fc340 RCX: 0000000000000000 [ 96.858115][ C1] RDX: dffffc0000000000 RSI: 0000000000000006 RDI: ffff8880a99fcbd4 [ 96.866082][ C1] RBP: ffffc90000d3fd98 R08: ffff8880a99fc340 R09: 0000000000000000 [ 96.874263][ C1] R10: 0000000000000000 R11: 0000000000000000 R12: dffffc0000000000 [ 96.882278][ C1] R13: ffffffff8aa522c0 R14: 0000000000000000 R15: 0000000000000001 [ 96.890271][ C1] ? default_idle+0x4e/0x360 [ 96.894987][ C1] arch_cpu_idle+0xa/0x10 [ 96.899361][ C1] default_idle_call+0x84/0xb0 [ 96.904208][ C1] do_idle+0x3c8/0x6e0 [ 96.908269][ C1] ? arch_cpu_idle_exit+0x80/0x80 [ 96.913716][ C