[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 85.731853][ T27] audit: type=1800 audit(1581113081.097:25): pid=9255 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2414 res=0 [ 85.756310][ T27] audit: type=1800 audit(1581113081.107:26): pid=9255 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2457 res=0 [ 85.802982][ T27] audit: type=1800 audit(1581113081.107:27): pid=9255 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 '10.128.0.24' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 96.135832][ T9407] IPVS: ftp: loaded support on port[0] = 21 [ 96.192868][ C1] [ 96.195295][ C1] ================================ [ 96.200391][ C1] WARNING: inconsistent lock state [ 96.205487][ C1] 5.5.0-syzkaller #0 Not tainted [ 96.210404][ C1] -------------------------------- [ 96.215494][ C1] inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage. [ 96.222369][ C1] swapper/1/0 [HC0[0]:SC1[1]:HE1:SE0] takes: [ 96.228329][ C1] ffff8880a7d671c8 (&(&local->client_conns_lock)->rlock){+.?.}, at: rxrpc_put_client_conn+0x6ed/0xc90 [ 96.239314][ C1] {SOFTIRQ-ON-W} state was registered at: [ 96.245020][ C1] lock_acquire+0x190/0x410 [ 96.249711][ C1] _raw_spin_lock+0x2f/0x40 [ 96.254279][ C1] rxrpc_connect_call+0x358/0x4e30 [ 96.259462][ C1] rxrpc_new_client_call+0x9c0/0x1ad0 [ 96.264897][ C1] rxrpc_do_sendmsg+0xffa/0x1d5f [ 96.269911][ C1] rxrpc_sendmsg+0x4d6/0x5f0 [ 96.274574][ C1] sock_sendmsg+0xd7/0x130 [ 96.279052][ C1] ____sys_sendmsg+0x358/0x880 [ 96.283892][ C1] ___sys_sendmsg+0x100/0x170 [ 96.288643][ C1] __sys_sendmmsg+0x1bf/0x4d0 [ 96.293389][ C1] __x64_sys_sendmmsg+0x9d/0x100 [ 96.298403][ C1] do_syscall_64+0xfa/0x790 [ 96.302980][ C1] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 96.308940][ C1] irq event stamp: 182092 [ 96.313254][ C1] hardirqs last enabled at (182092): [] _raw_spin_unlock_irqrestore+0x66/0xe0 [ 96.323743][ C1] hardirqs last disabled at (182091): [] _raw_spin_lock_irqsave+0x6f/0xcd [ 96.333796][ C1] softirqs last enabled at (182012): [] _local_bh_enable+0x1c/0x30 [ 96.343317][ C1] softirqs last disabled at (182013): [] irq_exit+0x19b/0x1e0 [ 96.352311][ C1] [ 96.352311][ C1] other info that might help us debug this: [ 96.360355][ C1] Possible unsafe locking scenario: [ 96.360355][ C1] [ 96.367788][ C1] CPU0 [ 96.371043][ C1] ---- [ 96.374309][ C1] lock(&(&local->client_conns_lock)->rlock); [ 96.380466][ C1] [ 96.383900][ C1] lock(&(&local->client_conns_lock)->rlock); [ 96.390207][ C1] [ 96.390207][ C1] *** DEADLOCK *** [ 96.390207][ C1] [ 96.398376][ C1] 1 lock held by swapper/1/0: [ 96.403023][ C1] #0: ffffffff89bac140 (rcu_callback){....}, at: rcu_core+0x562/0x1390 [ 96.411390][ C1] [ 96.411390][ C1] stack backtrace: [ 96.417274][ C1] CPU: 1 PID: 0 Comm: swapper/1 Not tainted 5.5.0-syzkaller #0 [ 96.424792][ C1] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 96.434832][ C1] Call Trace: [ 96.438136][ C1] [ 96.440972][ C1] dump_stack+0x197/0x210 [ 96.445280][ C1] print_usage_bug.cold+0x327/0x378 [ 96.450471][ C1] mark_lock+0xbb4/0x1220 [ 96.454781][ C1] ? kfree+0x10a/0x2c0 [ 96.458827][ C1] ? check_usage_backwards+0x330/0x330 [ 96.464273][ C1] ? __nf_hook_entries_free+0x31/0x40 [ 96.469640][ C1] __lock_acquire+0x1e8e/0x4a00 [ 96.474476][ C1] ? find_held_lock+0x35/0x130 [ 96.479234][ C1] ? __kasan_check_read+0x11/0x20 [ 96.484244][ C1] ? mark_lock+0xc2/0x1220 [ 96.488645][ C1] ? mark_held_locks+0xf0/0xf0 [ 96.493410][ C1] ? _raw_spin_unlock_irqrestore+0x66/0xe0 [ 96.499208][ C1] lock_acquire+0x190/0x410 [ 96.503716][ C1] ? rxrpc_put_client_conn+0x6ed/0xc90 [ 96.509343][ C1] _raw_spin_lock+0x2f/0x40 [ 96.513840][ C1] ? rxrpc_put_client_conn+0x6ed/0xc90 [ 96.519342][ C1] rxrpc_put_client_conn+0x6ed/0xc90 [ 96.524651][ C1] ? rxrpc_rcu_destroy_call+0xbd/0x200 [ 96.530226][ C1] rxrpc_rcu_destroy_call+0xbd/0x200 [ 96.535570][ C1] rcu_core+0x5e1/0x1390 [ 96.539793][ C1] ? __rcu_read_unlock+0x700/0x700 [ 96.544904][ C1] ? rcu_read_lock_sched_held+0x9c/0xd0 [ 96.550435][ C1] ? rcu_read_lock_any_held.part.0+0x50/0x50 [ 96.556408][ C1] ? run_rebalance_domains+0x227/0x2d0 [ 96.561854][ C1] rcu_core_si+0x9/0x10 [ 96.566053][ C1] __do_softirq+0x262/0x98c [ 96.570552][ C1] ? sched_clock_cpu+0x1b/0x1b0 [ 96.575396][ C1] irq_exit+0x19b/0x1e0 [ 96.579531][ C1] smp_apic_timer_interrupt+0x1a3/0x610 [ 96.585063][ C1] apic_timer_interrupt+0xf/0x20 [ 96.589983][ C1] [ 96.592953][ C1] RIP: 0010:native_safe_halt+0xe/0x10 [ 96.598306][ 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 [ 96.617901][ C1] RSP: 0018:ffffc90000d3fd68 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff13 [ 96.626299][ C1] RAX: 1ffffffff1367612 RBX: ffff8880a99fc340 RCX: 0000000000000000 [ 96.634259][ C1] RDX: dffffc0000000000 RSI: 0000000000000006 RDI: ffff8880a99fcbd4 [ 96.642220][ C1] RBP: ffffc90000d3fd98 R08: ffff8880a99fc340 R09: 0000000000000000 [ 96.650175][ C1] R10: 0000000000000000 R11: 0000000000000000 R12: dffffc0000000000 [ 96.658135][ C1] R13: ffffffff8aa522c0 R14: 0000000000000000 R15: 0000000000000001 [ 96.666108][ C1] ? default_idle+0x4e/0x360 [ 96.670690][ C1] arch_cpu_idle+0xa/0x10 [ 96.675004][ C1] default_idle_call+0x84/0xb0 [ 96.679755][ C1] do_idle+0x3c8/0x6e0 [ 96.683815][ C1] ? arch_cpu_idle_exit+0x80/0x80 [ 96.688834][ C1] ? _raw_spin_unlock_irqrestore+0x9f/0xe0 [ 96