[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 53.117854][ T26] audit: type=1800 audit(1567339135.679:25): pid=8407 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2414 res=0 [ 53.165218][ T26] audit: type=1800 audit(1567339135.679:26): pid=8407 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2457 res=0 [ 53.200484][ T26] audit: type=1800 audit(1567339135.679:27): pid=8407 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 '10.128.0.168' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 65.864779][ C0] [ 65.867130][ C0] ======================================================== [ 65.874290][ C0] WARNING: possible irq lock inversion dependency detected [ 65.881452][ C0] 5.3.0-rc6-next-20190830 #75 Not tainted [ 65.887137][ C0] -------------------------------------------------------- [ 65.894294][ C0] swapper/0/0 just changed the state of lock: [ 65.900328][ C0] ffff8880914ebb58 (&(&ctx->ctx_lock)->rlock){..-.}, at: free_ioctx_users+0x2d/0x490 [ 65.909777][ C0] but this lock took another, SOFTIRQ-unsafe lock in the past: [ 65.917297][ C0] (&fiq->waitq){+.+.} [ 65.917302][ C0] [ 65.917302][ C0] [ 65.917302][ C0] and interrupts could create inverse lock ordering between them. [ 65.917302][ C0] [ 65.935612][ C0] [ 65.935612][ C0] other info that might help us debug this: [ 65.943638][ C0] Possible interrupt unsafe locking scenario: [ 65.943638][ C0] [ 65.951922][ C0] CPU0 CPU1 [ 65.957257][ C0] ---- ---- [ 65.962593][ C0] lock(&fiq->waitq); [ 65.966629][ C0] local_irq_disable(); [ 65.973351][ C0] lock(&(&ctx->ctx_lock)->rlock); [ 65.981031][ C0] lock(&fiq->waitq); [ 65.987582][ C0] [ 65.991006][ C0] lock(&(&ctx->ctx_lock)->rlock); [ 65.996343][ C0] [ 65.996343][ C0] *** DEADLOCK *** [ 65.996343][ C0] [ 66.004461][ C0] 2 locks held by swapper/0/0: [ 66.009189][ C0] #0: ffffffff88fa7e40 (rcu_callback){....}, at: rcu_core+0x60e/0x1560 [ 66.017492][ C0] #1: ffffffff88fa7e80 (rcu_read_lock_sched){....}, at: percpu_ref_switch_to_atomic_rcu+0x20e/0x570 [ 66.028313][ C0] [ 66.028313][ C0] the shortest dependencies between 2nd lock and 1st lock: [ 66.037661][ C0] -> (&fiq->waitq){+.+.} { [ 66.042137][ C0] HARDIRQ-ON-W at: [ 66.046193][ C0] lock_acquire+0x190/0x410 [ 66.052504][ C0] _raw_spin_lock+0x2f/0x40 [ 66.058801][ C0] flush_bg_queue+0x1f1/0x3b0 [ 66.065271][ C0] fuse_request_queue_background+0x2f8/0x5b0 [ 66.073039][ C0] fuse_request_send_background+0x58/0x110 [ 66.080655][ C0] cuse_channel_open+0x5c3/0x839 [ 66.087388][ C0] misc_open+0x395/0x4c0 [ 66.093463][ C0] chrdev_open+0x245/0x6b0 [ 66.099676][ C0] do_dentry_open+0x4df/0x1250 [ 66.106228][ C0] vfs_open+0xa0/0xd0 [ 66.112000][ C0] path_openat+0x10e9/0x46d0 [ 66.118380][ C0] do_filp_open+0x1a1/0x280 [ 66.124675][ C0] do_sys_open+0x3fe/0x5d0 [ 66.130881][ C0] __x64_sys_openat+0x9d/0x100 [ 66.137437][ C0] do_syscall_64+0xfa/0x760 [ 66.143732][ C0] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 66.151413][ C0] SOFTIRQ-ON-W at: [ 66.155456][ C0] lock_acquire+0x190/0x410 [ 66.161752][ C0] _raw_spin_lock+0x2f/0x40 [ 66.168044][ C0] flush_bg_queue+0x1f1/0x3b0 [ 66.174511][ C0] fuse_request_queue_background+0x2f8/0x5b0 [ 66.182280][ C0] fuse_request_send_background+0x58/0x110 [ 66.189874][ C0] cuse_channel_open+0x5c3/0x839 [ 66.196604][ C0] misc_open+0x395/0x4c0 [ 66.202639][ C0] chrdev_open+0x245/0x6b0 [ 66.208862][ C0] do_dentry_open+0x4df/0x1250 [ 66.215420][ C0] vfs_open+0xa0/0xd0 [ 66.221193][ C0] path_openat+0x10e9/0x46d0 [ 66.227575][ C0] do_filp_open+0x1a1/0x280 [ 66.233882][ C0] do_sys_open+0x3fe/0x5d0 [ 66.240089][ C0] __x64_sys_openat+0x9d/0x100 [ 66.246644][ C0] do_syscall_64+0xfa/0x760 [ 66.252939][ C0] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 66.260620][ C0] INITIAL USE at: [ 66.264587][ C0] lock_acquire+0x190/0x410 [ 66.270808][ C0] _raw_spin_lock+0x2f/0x40 [ 66.277019][ C0] flush_bg_queue+0x1f1/0x3b0 [ 66.283403][ C0] fuse_request_queue_background+0x2f8/0x5b0 [ 66.291090][ C0] fuse_request_send_background+0x58/0x110 [ 66.298599][ C0] cuse_channel_open+0x5c3/0x839 [ 66.305256][ C0] misc_open+0x395/0x4c0 [ 66.311205][ C0] chrdev_open+0x245/0x6b0 [ 66.317342][ C0] do_dentry_open+0x4df/0x1250 [ 66.323820][ C0] vfs_open+0xa0/0xd0 [ 66.329508][ C0] path_openat+0x10e9/0x46d0 [ 66.335802][ C0] do_filp_open+0x1a1/0x280 [ 66.342011][ C0] do_sys_open+0x3fe/0x5d0 [ 66.348129][ C0] __x64_sys_openat+0x9d/0x100 [ 66.354608][ C0] do_syscall_64+0xfa/0x760 [ 66.360823][ C0] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 66.368415][ C0] } [ 66.370980][ C0] ... key at: [] __key.44810+0x0/0x40 [ 66.378491][ C0] ... acquired at: [ 66.382362][ C0] _raw_spin_lock+0x2f/0x40 [ 66.387021][ C0] io_submit_one+0xefa/0x2ef0 [ 66.391863][ C0] __x64_sys_io_submit+0x1bd/0x570 [ 66.397146][ C0] do_syscall_64+0xfa/0x760 [ 66.401810][ C0] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 66.407848][ C0] [ 66.410159][ C0] -> (&(&ctx->ctx_lock)->rlock){..-.} { [ 66.415688][ C0] IN-SOFTIRQ-W at: [ 66.419645][ C0] lock_acquire+0x190/0x410 [ 66.425771][ C0] _raw_spin_lock_irq+0x60/0x80 [ 66.432241][ C0] free_ioctx_users+0x2d/0x490 [ 66.438638][ C0] percpu_ref_switch_to_atomic_rcu+0x4c0/0x570 [ 66.446451][ C0] rcu_core+0x581/0x1560 [ 66.452326][ C0] rcu_core_si+0x9/0x10 [ 66.458113][ C0] __do_softirq+0x262/0x98c [ 66.464245][ C0] irq_exit+0x19b/0x1e0 [ 66.470022][ C0] smp_apic_timer_interrupt+0x1a3/0x610 [ 66.477188][ C0] apic_timer_interrupt+0xf/0x20 [ 66.483747][ C0] native_safe_halt+0xe/0x10 [ 66.489966][ C0] default_enter_idle+0x71/0xf0 [ 66.496439][ C0] cpuidle_enter_state+0xef/0xfb0 [ 66.503108][ C0] cpuidle_enter+0x4f/0xa0 [ 66.509160][ C0] do_idle+0x45f/0x6e0 [ 66.514868][ C0] cpu_startup_entry+0x1b/0x20 [ 66.521264][ C0] rest_init+0x245/0x37b [ 66.527143][ C0] arch_call_rest_init+0xe/0x1b [ 66.533622][ C0] start_kernel+0x904/0x943 [ 66.539756][ C0] x86_64_start_reservations+0x29/0x2b [ 66.546831][ C0] x86_64_start_kernel+0x77/0x7b [ 66.553391][ C0] secondary_startup_64+0xa4/0xb0 [ 66.560030][ C0] INITIAL USE at: [ 66.563895][ C0] lock_acquire+0x190/0x410 [ 66.569930][ C0] _raw_spin_lock_irq+0x60/0x80 [ 66.576313][ C0] io_submit_one+0xeb5/0x2ef0 [ 66.582534][ C0] __x64_sys_io_submit+0x1bd/0x570 [ 66.589176][ C0] do_syscall_64+0xfa/0x760 [ 66.595209][ C0] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 66.602625][ C0] } [ 66.605140][ C0] ... key at: [] __key.54358+0x0/0x40 [ 66.612558][ C0] ... acquired at: [ 66.616337][ C0] mark_lock+0x517/0x1220 [ 66.620809][ C0] __lock_acquire+0x1e8e/0x4a00 [ 66.625830][ C0] lock_acquire+0x190/0x410 [ 66.630477][ C0] _raw_spin_lock_irq+0x60/0x80 [ 66.635957][ C0] free_ioctx_users+0x2d/0x490 [ 66.640865][ C0] percpu_ref_switch_to_atomic_rcu+0x4c0/0x570 [ 66.647161][ C0] rcu_core+0x581/0x1560 [ 66.651544][ C0] rcu_core_si+0x9/0x10 [ 66.655843][ C0] __do_softirq+0x262/0x98c [ 66.660489][ C0] irq_exit+0x19b/0x1e0 [ 66.664785][ C0] smp_apic_timer_interrupt+0x1a3/0x610 [ 66.670472][ C0] apic_timer_interrupt+0xf/0x20 [ 66.675552][ C0] native_safe_halt+0xe/0x10 [ 66.680286][ C0] default_enter_idle+0x71/0xf0 [ 66.685276][ C0] cpuidle_enter_state+0xef/0xfb0 [ 66.690451][ C0] cpuidle_enter+0x4f/0xa0 [ 66.695025][ C0] do_idle+0x45f/0x6e0 [ 66.699236][ C0] cpu_startup_entry+0x1b/0x20 [ 66.704144][ C0] rest_init+0x245/0x37b [ 66.708532][ C0] arch_call_rest_init+0xe/0x1b [ 66.713526][ C0] start_kernel+0x904/0x943 [ 66.718172][ C0] x86_64_start_reservations+0x29/0x2b [ 66.723774][ C0] x86_64_start_kernel+0x77/0x7b [ 66.728853][ C0] secondary_startup_64+0xa4/0xb0 [ 66.734014][ C0] [ 66.736309][ C0] [ 66.736309][ C0] stack backtrace: [ 66.742172][ C0] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.3.0-rc6-next-20190830 #75 [ 66.750458][ C0] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 66.760494][ C0] Call Trace: [ 66.763750][ C0] [ 66.766577][ C0] dump_stack+0x172/0x1f0 [ 66.770877][ C0] print_irq_inversion_bug.part.0+0x2e4/0x2f1 [ 66.776913][ C0] check_usage_forwards.cold+0x20/0x29 [ 66.782342][ C0] ? check_usage_backwards+0x330/0x330 [ 66.787770][ C0] ? save_trace+0x3e/0x8c0 [ 66.792156][ C0] mark_lock+0x517/0x1220 [ 66.796456][ C0] ? check_usage_backwards+0x330/0x330 [ 66.801883][ C0] __lock_acquire+0x1e8e/0x4a00 [ 66.806702][ C0] ? __kasan_check_read+0x11/0x20 [ 66.811709][ C0] ? mark_lock+0xc2/0x1220 [ 66.816102][ C0] ? mark_held_locks+0xf0/0xf0 [ 66.820854][ C0] lock_acquire+0x190/0x410 [ 66.825331][ C0] ? free_ioctx_users+0x2d/0x490 [ 66.830258][ C0] _raw_spin_lock_irq+0x60/0x80 [ 66.835078][ C0] ? free_ioctx_users+0x2d/0x490 [ 66.839985][ C0] free_ioctx_users+0x2d/0x490 [ 66.844721][ C0] ? rcu_dynticks_curr_cpu_in_eqs+0x54/0xb0 [ 66.850585][ C0] percpu_ref_switch_to_atomic_rcu+0x4c0/0x570 [ 66.856711][ C0] ? percpu_ref_exit+0xd0/0xd0 [ 66.861444][ C0] rcu_core+0x581/0x1560 [ 66.865658][ C0] ? __rcu_read_unlock+0x6b0/0x6b0 [ 66.870738][ C0] ? rcu_read_lock_sched_held+0x9c/0xd0 [ 66.876253][ C0] ? rcu_read_lock_any_held.part.0+0x50/0x50 [ 66.882200][ C0] ? run_rebalance_domains+0x227/0x2d0 [ 66.887627][ C0] rcu_core_si+0x9/0x10 [ 66.891753][ C0] __do_softirq+0x262/0x98c [ 66.896223][ C0] ? sched_clock_cpu+0x1b/0x1b0 [ 66.901045][ C0] irq_exit+0x19b/0x1e0 [ 66.905180][ C0] smp_apic_timer_interrupt+0x1a3/0x610 [ 66.910693][ C0] apic_timer_interrupt+0xf/0x20 [ 66.915597][ C0] [ 66.918523][ C0] RIP: 0010:native_safe_halt+0xe/0x10 [ 66.923865][ C0] Code: 38 c1 69 fa eb 8a 90 90 90 90 90 90 e9 07 00 00 00 0f 00 2d 64 b8 64 00 f4 c3 66 90 e9 07 00 00 00 0f 00 2d 54 b8 64 00 fb f4 90 55 48 89 e5 41 57 41 56 41 55 41 54 53 e8 5e a7 1c fa e8 69 [ 66.943437][ C0] RSP: 0018:ffffffff88e07c50 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff13 [ 66.951817][ C0] RAX: 1ffffffff11e5db7 RBX: 0000000000000000 RCX: 0000000000000000 [ 66.959758][ C0] RDX: dffffc0000000000 RSI: 0000000000000006 RDI: ffffffff88e7aa1c [ 66.967698][ C0] RBP: ffffffff88e07c80 R08: ffffffff88e7a180 R09: 0000000000000000 [ 66.975637][ C0] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000001 [ 66.983580][ C0] R13: 0000000000000000 R14: 0000000000000060 R15: 0000000000000001 [ 66.991530][ C0] ? default_idle+0x4e/0x360 [ 66.996093][ C0] default_enter_idle+0x71/0xf0 [ 67.000918][ C0] cpuidle_enter_state+0xef/0xfb0 [ 67.005915][ C0] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 67.012123][ C0] cpuidle_enter+0x4f/0xa0 [ 67.016530][ C0] do_idle+0x45f/0x6e0 [ 67.020570][ C0] ? arch_cpu_idle_exit+0x80/0x80 [ 67.025563][ C0] ? trace_hardirqs_on+0x30/0x240 [ 67.030554][ C0] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 67.036764][ C0] ? debug_smp_processor_id+0x3c/0x214 [ 67.042207][ C0] cpu_startup_entry+0x1b/0x20 [ 67.046940][ C0] rest_init+0x245/0x37b [ 67.051157][ C0] arch_call_rest_init+0xe/0x1b [ 67.055978][ C0] start_kernel+0x904/0x943 [ 67.060452][ C0] ? mem_encrypt_init+0xb/0xb [ 67.065113][ C0] ? __sanitizer_cov_trace_const_c