[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [ 63.370909][ T8965] restorecond (8965) used greatest stack depth: 22952 bytes left [....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting file context maintaining daemon: restorecond[?25l[?1c7[ ok 8[?25h[?0c. [ 64.072921][ T26] kauditd_printk_skb: 38 callbacks suppressed [ 64.072935][ T26] audit: type=1400 audit(1569314846.864:70): avc: denied { map } for pid=9048 comm="bash" path="/bin/bash" dev="sda1" ino=1457 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=system_u:object_r:file_t:s0 tclass=file permissive=1 Debian GNU/Linux 7 syzkaller ttyS0 Warning: Permanently added '10.128.1.59' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 70.539830][ T26] audit: type=1400 audit(1569314853.324:71): avc: denied { map } for pid=9067 comm="syz-executor454" path="/root/syz-executor454795596" dev="sda1" ino=16502 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:object_r:user_home_t:s0 tclass=file permissive=1 [ 70.580115][ C1] [ 70.582449][ C1] ======================================================== [ 70.589613][ C1] WARNING: possible irq lock inversion dependency detected [ 70.596782][ C1] 5.3.0+ #0 Not tainted [ 70.600905][ C1] -------------------------------------------------------- [ 70.608078][ C1] swapper/1/0 just changed the state of lock: [ 70.614116][ C1] ffff8880a1235b58 (&(&ctx->ctx_lock)->rlock){..-.}, at: free_ioctx_users+0x2d/0x490 [ 70.623569][ C1] but this lock took another, SOFTIRQ-unsafe lock in the past: [ 70.631080][ C1] (&fiq->waitq){+.+.} [ 70.631087][ C1] [ 70.631087][ C1] [ 70.631087][ C1] and interrupts could create inverse lock ordering between them. [ 70.631087][ C1] [ 70.649503][ C1] [ 70.649503][ C1] other info that might help us debug this: [ 70.657562][ C1] Possible interrupt unsafe locking scenario: [ 70.657562][ C1] [ 70.665864][ C1] CPU0 CPU1 [ 70.671211][ C1] ---- ---- [ 70.676550][ C1] lock(&fiq->waitq); [ 70.680593][ C1] local_irq_disable(); [ 70.687321][ C1] lock(&(&ctx->ctx_lock)->rlock); [ 70.695053][ C1] lock(&fiq->waitq); [ 70.701614][ C1] [ 70.705043][ C1] lock(&(&ctx->ctx_lock)->rlock); [ 70.710385][ C1] [ 70.710385][ C1] *** DEADLOCK *** [ 70.710385][ C1] [ 70.718504][ C1] 2 locks held by swapper/1/0: [ 70.723234][ C1] #0: ffffffff88fab240 (rcu_callback){....}, at: rcu_core+0x60e/0x1560 [ 70.731540][ C1] #1: ffffffff88fab280 (rcu_read_lock_sched){....}, at: percpu_ref_switch_to_atomic_rcu+0x20e/0x570 [ 70.743146][ C1] [ 70.743146][ C1] the shortest dependencies between 2nd lock and 1st lock: [ 70.752485][ C1] -> (&fiq->waitq){+.+.} { [ 70.756960][ C1] HARDIRQ-ON-W at: [ 70.761019][ C1] lock_acquire+0x190/0x410 [ 70.767318][ C1] _raw_spin_lock+0x2f/0x40 [ 70.773617][ C1] flush_bg_queue+0x1f3/0x3c0 [ 70.780108][ C1] fuse_request_queue_background+0x2f8/0x5a0 [ 70.787884][ C1] fuse_request_send_background+0x58/0x110 [ 70.795487][ C1] cuse_channel_open+0x5ba/0x830 [ 70.802222][ C1] misc_open+0x395/0x4c0 [ 70.808261][ C1] chrdev_open+0x245/0x6b0 [ 70.814484][ C1] do_dentry_open+0x4df/0x1250 [ 70.821041][ C1] vfs_open+0xa0/0xd0 [ 70.826818][ C1] path_openat+0x10e9/0x4630 [ 70.833206][ C1] do_filp_open+0x1a1/0x280 [ 70.839502][ C1] do_sys_open+0x3fe/0x5d0 [ 70.845714][ C1] __x64_sys_openat+0x9d/0x100 [ 70.852284][ C1] do_syscall_64+0xfa/0x760 [ 70.858583][ C1] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 70.866270][ C1] SOFTIRQ-ON-W at: [ 70.870318][ C1] lock_acquire+0x190/0x410 [ 70.876615][ C1] _raw_spin_lock+0x2f/0x40 [ 70.882921][ C1] flush_bg_queue+0x1f3/0x3c0 [ 70.889397][ C1] fuse_request_queue_background+0x2f8/0x5a0 [ 70.897172][ C1] fuse_request_send_background+0x58/0x110 [ 70.904771][ C1] cuse_channel_open+0x5ba/0x830 [ 70.911506][ C1] misc_open+0x395/0x4c0 [ 70.917550][ C1] chrdev_open+0x245/0x6b0 [ 70.923777][ C1] do_dentry_open+0x4df/0x1250 [ 70.930359][ C1] vfs_open+0xa0/0xd0 [ 70.936138][ C1] path_openat+0x10e9/0x4630 [ 70.942524][ C1] do_filp_open+0x1a1/0x280 [ 70.948822][ C1] do_sys_open+0x3fe/0x5d0 [ 70.955044][ C1] __x64_sys_openat+0x9d/0x100 [ 70.961607][ C1] do_syscall_64+0xfa/0x760 [ 70.967907][ C1] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 70.975601][ C1] INITIAL USE at: [ 70.979560][ C1] lock_acquire+0x190/0x410 [ 70.985774][ C1] _raw_spin_lock+0x2f/0x40 [ 70.991992][ C1] flush_bg_queue+0x1f3/0x3c0 [ 70.998377][ C1] fuse_request_queue_background+0x2f8/0x5a0 [ 71.006063][ C1] fuse_request_send_background+0x58/0x110 [ 71.013581][ C1] cuse_channel_open+0x5ba/0x830 [ 71.020231][ C1] misc_open+0x395/0x4c0 [ 71.026183][ C1] chrdev_open+0x245/0x6b0 [ 71.032307][ C1] do_dentry_open+0x4df/0x1250 [ 71.038775][ C1] vfs_open+0xa0/0xd0 [ 71.044465][ C1] path_openat+0x10e9/0x4630 [ 71.050763][ C1] do_filp_open+0x1a1/0x280 [ 71.056978][ C1] do_sys_open+0x3fe/0x5d0 [ 71.063104][ C1] __x64_sys_openat+0x9d/0x100 [ 71.069577][ C1] do_syscall_64+0xfa/0x760 [ 71.075801][ C1] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 71.083409][ C1] } [ 71.085981][ C1] ... key at: [] __key.44672+0x0/0x40 [ 71.093491][ C1] ... acquired at: [ 71.097358][ C1] _raw_spin_lock+0x2f/0x40 [ 71.102017][ C1] io_submit_one+0xefa/0x2ef0 [ 71.106840][ C1] __x64_sys_io_submit+0x1bd/0x570 [ 71.112097][ C1] do_syscall_64+0xfa/0x760 [ 71.117874][ C1] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 71.123904][ C1] [ 71.126204][ C1] -> (&(&ctx->ctx_lock)->rlock){..-.} { [ 71.131724][ C1] IN-SOFTIRQ-W at: [ 71.135693][ C1] lock_acquire+0x190/0x410 [ 71.141818][ C1] _raw_spin_lock_irq+0x60/0x80 [ 71.148377][ C1] free_ioctx_users+0x2d/0x490 [ 71.154767][ C1] percpu_ref_switch_to_atomic_rcu+0x4c0/0x570 [ 71.162542][ C1] rcu_core+0x581/0x1560 [ 71.168403][ C1] rcu_core_si+0x9/0x10 [ 71.174184][ C1] __do_softirq+0x262/0x98c [ 71.180308][ C1] irq_exit+0x19b/0x1e0 [ 71.186085][ C1] smp_apic_timer_interrupt+0x1a3/0x610 [ 71.193251][ C1] apic_timer_interrupt+0xf/0x20 [ 71.199896][ C1] native_safe_halt+0xe/0x10 [ 71.206120][ C1] arch_cpu_idle+0xa/0x10 [ 71.212082][ C1] default_idle_call+0x84/0xb0 [ 71.218467][ C1] do_idle+0x3b7/0x6e0 [ 71.224168][ C1] cpu_startup_entry+0x1b/0x20 [ 71.230557][ C1] start_secondary+0x2f4/0x410 [ 71.237050][ C1] secondary_startup_64+0xa4/0xb0 [ 71.243693][ C1] INITIAL USE at: [ 71.247583][ C1] lock_acquire+0x190/0x410 [ 71.253624][ C1] _raw_spin_lock_irq+0x60/0x80 [ 71.260025][ C1] io_submit_one+0xeb5/0x2ef0 [ 71.266242][ C1] __x64_sys_io_submit+0x1bd/0x570 [ 71.272887][ C1] do_syscall_64+0xfa/0x760 [ 71.278924][ C1] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 71.286359][ C1] } [ 71.288843][ C1] ... key at: [] __key.54293+0x0/0x40 [ 71.296265][ C1] ... acquired at: [ 71.300047][ C1] mark_lock+0x517/0x1220 [ 71.304520][ C1] __lock_acquire+0x1eaf/0x4e70 [ 71.309515][ C1] lock_acquire+0x190/0x410 [ 71.314164][ C1] _raw_spin_lock_irq+0x60/0x80 [ 71.319161][ C1] free_ioctx_users+0x2d/0x490 [ 71.324082][ C1] percpu_ref_switch_to_atomic_rcu+0x4c0/0x570 [ 71.330381][ C1] rcu_core+0x581/0x1560 [ 71.334782][ C1] rcu_core_si+0x9/0x10 [ 71.339094][ C1] __do_softirq+0x262/0x98c [ 71.343742][ C1] irq_exit+0x19b/0x1e0 [ 71.348055][ C1] smp_apic_timer_interrupt+0x1a3/0x610 [ 71.353746][ C1] apic_timer_interrupt+0xf/0x20 [ 71.358829][ C1] native_safe_halt+0xe/0x10 [ 71.363567][ C1] arch_cpu_idle+0xa/0x10 [ 71.368040][ C1] default_idle_call+0x84/0xb0 [ 71.372952][ C1] do_idle+0x3b7/0x6e0 [ 71.377166][ C1] cpu_startup_entry+0x1b/0x20 [ 71.382074][ C1] start_secondary+0x2f4/0x410 [ 71.386993][ C1] secondary_startup_64+0xa4/0xb0 [ 71.392169][ C1] [ 71.394468][ C1] [ 71.394468][ C1] stack backtrace: [ 71.400333][ C1] CPU: 1 PID: 0 Comm: swapper/1 Not tainted 5.3.0+ #0 [ 71.407061][ C1] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 71.417089][ C1] Call Trace: [ 71.420346][ C1] [ 71.423177][ C1] dump_stack+0x172/0x1f0 [ 71.427496][ C1] print_irq_inversion_bug.part.0+0x2e4/0x2f1 [ 71.433537][ C1] check_usage_forwards.cold+0x20/0x29 [ 71.438978][ C1] ? check_usage_backwards+0x330/0x330 [ 71.444426][ C1] ? secondary_startup_64+0xa4/0xb0 [ 71.449600][ C1] mark_lock+0x517/0x1220 [ 71.453904][ C1] ? check_usage_backwards+0x330/0x330 [ 71.459336][ C1] __lock_acquire+0x1eaf/0x4e70 [ 71.464159][ C1] ? __kasan_check_read+0x11/0x20 [ 71.469157][ C1] ? mark_lock+0xc2/0x1220 [ 71.473548][ C1] ? mark_held_locks+0xf0/0xf0 [ 71.478300][ C1] lock_acquire+0x190/0x410 [ 71.482778][ C1] ? free_ioctx_users+0x2d/0x490 [ 71.487690][ C1] _raw_spin_lock_irq+0x60/0x80 [ 71.492525][ C1] ? free_ioctx_users+0x2d/0x490 [ 71.497449][ C1] free_ioctx_users+0x2d/0x490 [ 71.502199][ C1] ? rcu_dynticks_curr_cpu_in_eqs+0x54/0xb0 [ 71.508073][ C1] percpu_ref_switch_to_atomic_rcu+0x4c0/0x570 [ 71.514204][ C1] ? percpu_ref_exit+0xd0/0xd0 [ 71.518947][ C1] rcu_core+0x581/0x1560 [ 71.523168][ C1] ? __rcu_read_unlock+0x6b0/0x6b0 [ 71.528256][ C1] ? rcu_read_lock_sched_held+0x9c/0xd0 [ 71.533791][ C1] ? rcu_read_lock_any_held.part.0+0x50/0x50 [ 71.539745][ C1] ? run_rebalance_domains+0x227/0x2d0 [ 71.545264][ C1] rcu_core_si+0x9/0x10 [ 71.549397][ C1] __do_softirq+0x262/0x98c [ 71.553885][ C1] ? sched_clock_cpu+0x1b/0x1b0 [ 71.558709][ C1] irq_exit+0x19b/0x1e0 [ 71.562849][ C1] smp_apic_timer_interrupt+0x1a3/0x610 [ 71.568366][ C1] apic_timer_interrupt+0xf/0x20 [ 71.573273][ C1] [ 71.576185][ C1] RIP: 0010:native_safe_halt+0xe/0x10 [ 71.581533][ C1] Code: 38 8e 66 fa eb 8a 90 90 90 90 90 90 e9 07 00 00 00 0f 00 2d 54 25 61 00 f4 c3 66 90 e9 07 00 00 00 0f 00 2d 44 25 61 00 fb f4 90 55 48 89 e5 41 57 41 56 41 55 41 54 53 e8 9e 83 19 fa e8 b9 [ 71.601110][ C1] RSP: 0018:ffff8880a98e7d68 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff13 [ 71.609490][ C1] RAX: 1ffffffff11e630f RBX: ffff8880a98d4340 RCX: 0000000000000000 [ 71.617435][ C1] RDX: dffffc0000000000 RSI: 0000000000000006 RDI: ffff8880a98d4bd4 [ 71.625394][ C1] RBP: ffff8880a98e7d98 R08: ffff8880a98d4340 R09: 0000000000000000 [ 71.633356][ C1] R10: 0000000000000000 R11: 0000000000000000 R12: dffffc0000000000 [ 71.641304][ C1] R13: ffffffff89c6b5c0 R14: 0000000000000000 R15: 0000000000000001 [ 71.649271][ C1] ? default_idle+0x4e/0x360 [ 71.653888][ C1] arch_cpu_idle+0xa/0x10 [ 71.658194][ C1] default_idle_call+0x84/0xb0 [ 71.662995][ C1] do_idle+0x3b7/0x6e0 [ 71.667042][ C1] ? arch_cpu_idle_exit+0x80/0x80 [ 71.672066][ C1] ? _raw_spin_unlock_irqrestore+0xa4/0xe0 [ 71.677851][ C1] ? complete+0x61/0x80 [ 71.681986][ C1] cpu_startup_entry+0x1b/0x20 [ 71.686727][ C1] start_secondary+0x2f4/0x410 [ 71.691475][ C1] ? set_cpu_sibling_map