[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 68.129342][ T27] audit: type=1800 audit(1581071536.501:25): pid=9516 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2414 res=0 [ 68.150426][ T27] audit: type=1800 audit(1581071536.511:26): pid=9516 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2457 res=0 [ 68.209008][ T27] audit: type=1800 audit(1581071536.511:27): pid=9516 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 '10.128.0.75' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 82.485458][ T9671] IPVS: ftp: loaded support on port[0] = 21 [ 82.540379][ C0] [ 82.542778][ C0] ================================ [ 82.547868][ C0] WARNING: inconsistent lock state [ 82.552949][ C0] 5.5.0-syzkaller #0 Not tainted [ 82.557894][ C0] -------------------------------- [ 82.562977][ C0] inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage. [ 82.569830][ C0] swapper/0/0 [HC0[0]:SC1[1]:HE1:SE0] takes: [ 82.575796][ C0] ffff8880a4bd21c8 (&(&local->client_conns_lock)->rlock){+.?.}, at: rxrpc_put_client_conn+0x6ed/0xc90 [ 82.586731][ C0] {SOFTIRQ-ON-W} state was registered at: [ 82.592427][ C0] lock_acquire+0x190/0x410 [ 82.596994][ C0] _raw_spin_lock+0x2f/0x40 [ 82.601556][ C0] rxrpc_connect_call+0x358/0x4e30 [ 82.606725][ C0] rxrpc_new_client_call+0x9c0/0x1ad0 [ 82.612152][ C0] rxrpc_do_sendmsg+0xffa/0x1d5f [ 82.617149][ C0] rxrpc_sendmsg+0x4d6/0x5f0 [ 82.621798][ C0] sock_sendmsg+0xd7/0x130 [ 82.626273][ C0] ____sys_sendmsg+0x358/0x880 [ 82.631125][ C0] ___sys_sendmsg+0x100/0x170 [ 82.635860][ C0] __sys_sendmmsg+0x1bf/0x4d0 [ 82.641199][ C0] __x64_sys_sendmmsg+0x9d/0x100 [ 82.646210][ C0] do_syscall_64+0xfa/0x790 [ 82.650779][ C0] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 82.656745][ C0] irq event stamp: 156492 [ 82.661056][ C0] hardirqs last enabled at (156492): [] _raw_spin_unlock_irqrestore+0x66/0xe0 [ 82.671536][ C0] hardirqs last disabled at (156491): [] _raw_spin_lock_irqsave+0x6f/0xcd [ 82.681583][ C0] softirqs last enabled at (156416): [] _local_bh_enable+0x1c/0x30 [ 82.691099][ C0] softirqs last disabled at (156417): [] irq_exit+0x19b/0x1e0 [ 82.700091][ C0] [ 82.700091][ C0] other info that might help us debug this: [ 82.708134][ C0] Possible unsafe locking scenario: [ 82.708134][ C0] [ 82.715605][ C0] CPU0 [ 82.718861][ C0] ---- [ 82.722117][ C0] lock(&(&local->client_conns_lock)->rlock); [ 82.728245][ C0] [ 82.731676][ C0] lock(&(&local->client_conns_lock)->rlock); [ 82.737973][ C0] [ 82.737973][ C0] *** DEADLOCK *** [ 82.737973][ C0] [ 82.746139][ C0] 1 lock held by swapper/0/0: [ 82.750782][ C0] #0: ffffffff89bac140 (rcu_callback){....}, at: rcu_core+0x562/0x1390 [ 82.759090][ C0] [ 82.759090][ C0] stack backtrace: [ 82.764955][ C0] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.5.0-syzkaller #0 [ 82.772464][ C0] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 82.782491][ C0] Call Trace: [ 82.785782][ C0] [ 82.788611][ C0] dump_stack+0x197/0x210 [ 82.792954][ C0] print_usage_bug.cold+0x327/0x378 [ 82.798127][ C0] mark_lock+0xbb4/0x1220 [ 82.802429][ C0] ? kfree+0x10a/0x2c0 [ 82.806470][ C0] ? check_usage_backwards+0x330/0x330 [ 82.811911][ C0] ? __nf_hook_entries_free+0x31/0x40 [ 82.817264][ C0] __lock_acquire+0x1e8e/0x4a00 [ 82.822101][ C0] ? find_held_lock+0x35/0x130 [ 82.826842][ C0] ? __kasan_check_read+0x11/0x20 [ 82.831836][ C0] ? mark_lock+0xc2/0x1220 [ 82.836227][ C0] ? mark_held_locks+0xf0/0xf0 [ 82.840980][ C0] ? _raw_spin_unlock_irqrestore+0x66/0xe0 [ 82.846758][ C0] lock_acquire+0x190/0x410 [ 82.851237][ C0] ? rxrpc_put_client_conn+0x6ed/0xc90 [ 82.856683][ C0] _raw_spin_lock+0x2f/0x40 [ 82.861159][ C0] ? rxrpc_put_client_conn+0x6ed/0xc90 [ 82.866602][ C0] rxrpc_put_client_conn+0x6ed/0xc90 [ 82.872036][ C0] ? rxrpc_rcu_destroy_call+0xbd/0x200 [ 82.877472][ C0] rxrpc_rcu_destroy_call+0xbd/0x200 [ 82.882735][ C0] rcu_core+0x5e1/0x1390 [ 82.886958][ C0] ? __rcu_read_unlock+0x700/0x700 [ 82.892045][ C0] ? rcu_read_lock_sched_held+0x9c/0xd0 [ 82.897596][ C0] ? rcu_read_lock_any_held.part.0+0x50/0x50 [ 82.903570][ C0] ? run_rebalance_domains+0x227/0x2d0 [ 82.909004][ C0] rcu_core_si+0x9/0x10 [ 82.913133][ C0] __do_softirq+0x262/0x98c [ 82.917610][ C0] ? sched_clock_cpu+0x1b/0x1b0 [ 82.922434][ C0] irq_exit+0x19b/0x1e0 [ 82.926573][ C0] smp_apic_timer_interrupt+0x1a3/0x610 [ 82.932103][ C0] apic_timer_interrupt+0xf/0x20 [ 82.937011][ C0] [ 82.939927][ C0] RIP: 0010:native_safe_halt+0xe/0x10 [ 82.945280][ C0] 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 [ 82.964857][ C0] RSP: 0018:ffffffff89a07ce8 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff13 [ 82.973240][ C0] RAX: 1ffffffff1367612 RBX: ffffffff89a7a440 RCX: 0000000000000000 [ 82.981187][ C0] RDX: dffffc0000000000 RSI: 0000000000000006 RDI: ffffffff89a7acd4 [ 82.989130][ C0] RBP: ffffffff89a07d18 R08: ffffffff89a7a440 R09: 0000000000000000 [ 82.997074][ C0] R10: 0000000000000000 R11: 0000000000000000 R12: dffffc0000000000 [ 83.005028][ C0] R13: ffffffff8aa522c0 R14: 0000000000000000 R15: 0000000000000000 [ 83.012993][ C0] ? default_idle+0x4e/0x360 [ 83.017569][ C0] arch_cpu_idle+0xa/0x10 [ 83.021876][ C0] default_idle_call+0x84/0xb0 [ 83.026610][ C0] do_idle+0x3c8/0x6e0 [ 83.030652][ C0] ? arch_cpu_idle_exit+0x80/0x80 [ 83.035648][ C0] ? trace_hardirqs_on+0x67/0x240 [ 83.040656][ C0] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 83.046911][ C0] ? debug_smp_processor_id+0x33/0x18a [ 83.052346][ C0] cpu_startup_entry+0x1b/0x20 [ 83.057087][ C0] rest_init+0x23b/0x371 [ 83.061306][ C0] ? trace_init_perf_perm_irq_work_exit+0xe/0xe [ 83.067537][ C0] arch_call_rest_init+0xe/0x1b [ 83.072370][ C0] start_kernel+0x886/0x8c5 [ 83.076848][ C0] ? mem_encrypt_init+0xb/0xb [ 83.081503][ C0] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 83.087724][ C0] ? x86_family+0x41/0x50 [ 83.092029