Starting mcstransd: [....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting file context maintaining daemon: restorecond[?25l[?1c7[ ok 8[?25h[?0c. [ 37.775043] audit: type=1800 audit(1567192479.069:33): pid=7257 uid=0 auid=4294967295 ses=4294967295 subj=system_u:system_r:kernel_t:s0 op=collect_data cause=failed(directio) comm="startpar" name="rc.local" dev="sda1" ino=2465 res=0 [ 37.796841] audit: type=1800 audit(1567192479.069:34): pid=7257 uid=0 auid=4294967295 ses=4294967295 subj=system_u:system_r:kernel_t:s0 op=collect_data cause=failed(directio) comm="startpar" name="rmnologin" dev="sda1" ino=2456 res=0 Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 40.593559] audit: type=1400 audit(1567192481.889:35): avc: denied { map } for pid=7431 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 Warning: Permanently added '10.128.0.50' (ECDSA) to the list of known hosts. executing program [ 47.134665] audit: type=1400 audit(1567192488.429:36): avc: denied { map } for pid=7444 comm="syz-executor466" path="/root/syz-executor466343875" dev="sda1" ino=16483 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:object_r:user_home_t:s0 tclass=file permissive=1 [ 47.163054] [ 47.164683] ======================================================== [ 47.171148] WARNING: possible irq lock inversion dependency detected [ 47.177617] 4.19.69 #43 Not tainted [ 47.181217] -------------------------------------------------------- [ 47.187684] swapper/1/0 just changed the state of lock: [ 47.193020] 0000000067584a40 (&(&ctx->ctx_lock)->rlock){..-.}, at: free_ioctx_users+0x2d/0x490 [ 47.201763] but this lock took another, SOFTIRQ-unsafe lock in the past: [ 47.208577] (&fiq->waitq){+.+.} [ 47.208585] [ 47.208585] [ 47.208585] and interrupts could create inverse lock ordering between them. [ 47.208585] [ 47.223449] [ 47.223449] other info that might help us debug this: [ 47.230089] Possible interrupt unsafe locking scenario: [ 47.230089] [ 47.237029] CPU0 CPU1 [ 47.241673] ---- ---- [ 47.246312] lock(&fiq->waitq); [ 47.249670] local_irq_disable(); [ 47.255702] lock(&(&ctx->ctx_lock)->rlock); [ 47.262691] lock(&fiq->waitq); [ 47.268549] [ 47.271318] lock(&(&ctx->ctx_lock)->rlock); [ 47.275964] [ 47.275964] *** DEADLOCK *** [ 47.275964] [ 47.282005] 2 locks held by swapper/1/0: [ 47.286041] #0: 00000000d43b8cad (rcu_callback){....}, at: rcu_process_callbacks+0xc79/0x1a30 [ 47.294792] #1: 0000000031d4e75e (rcu_read_lock_sched){....}, at: percpu_ref_switch_to_atomic_rcu+0x1ca/0x540 [ 47.304925] [ 47.304925] the shortest dependencies between 2nd lock and 1st lock: [ 47.312877] -> (&fiq->waitq){+.+.} ops: 4 { [ 47.317278] HARDIRQ-ON-W at: [ 47.320626] lock_acquire+0x16f/0x3f0 [ 47.326231] _raw_spin_lock+0x2f/0x40 [ 47.331835] flush_bg_queue+0x1f3/0x3d0 [ 47.337613] fuse_request_send_background_locked+0x26d/0x4e0 [ 47.345219] fuse_request_send_background+0x12b/0x180 [ 47.352214] cuse_channel_open+0x5ba/0x830 [ 47.358255] misc_open+0x395/0x4c0 [ 47.363601] chrdev_open+0x245/0x6b0 [ 47.369119] do_dentry_open+0x4c3/0x1210 [ 47.374984] vfs_open+0xa0/0xd0 [ 47.380066] path_openat+0x10d7/0x45e0 [ 47.385756] do_filp_open+0x1a1/0x280 [ 47.391359] do_sys_open+0x3fe/0x550 [ 47.396874] __x64_sys_openat+0x9d/0x100 [ 47.402741] do_syscall_64+0xfd/0x620 [ 47.408383] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 47.415457] SOFTIRQ-ON-W at: [ 47.418827] lock_acquire+0x16f/0x3f0 [ 47.424437] _raw_spin_lock+0x2f/0x40 [ 47.430057] flush_bg_queue+0x1f3/0x3d0 [ 47.435840] fuse_request_send_background_locked+0x26d/0x4e0 [ 47.443441] fuse_request_send_background+0x12b/0x180 [ 47.450447] cuse_channel_open+0x5ba/0x830 [ 47.456574] misc_open+0x395/0x4c0 [ 47.461917] chrdev_open+0x245/0x6b0 [ 47.467435] do_dentry_open+0x4c3/0x1210 [ 47.473298] vfs_open+0xa0/0xd0 [ 47.478392] path_openat+0x10d7/0x45e0 [ 47.484084] do_filp_open+0x1a1/0x280 [ 47.489688] do_sys_open+0x3fe/0x550 [ 47.495223] __x64_sys_openat+0x9d/0x100 [ 47.501090] do_syscall_64+0xfd/0x620 [ 47.506711] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 47.513702] INITIAL USE at: [ 47.516981] lock_acquire+0x16f/0x3f0 [ 47.522498] _raw_spin_lock+0x2f/0x40 [ 47.528033] flush_bg_queue+0x1f3/0x3d0 [ 47.533815] fuse_request_send_background_locked+0x26d/0x4e0 [ 47.541357] fuse_request_send_background+0x12b/0x180 [ 47.548279] cuse_channel_open+0x5ba/0x830 [ 47.554245] misc_open+0x395/0x4c0 [ 47.559676] chrdev_open+0x245/0x6b0 [ 47.565108] do_dentry_open+0x4c3/0x1210 [ 47.570883] vfs_open+0xa0/0xd0 [ 47.575880] path_openat+0x10d7/0x45e0 [ 47.581484] do_filp_open+0x1a1/0x280 [ 47.587085] do_sys_open+0x3fe/0x550 [ 47.592516] __x64_sys_openat+0x9d/0x100 [ 47.598297] do_syscall_64+0xfd/0x620 [ 47.603835] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 47.610743] } [ 47.612637] ... key at: [] __key.42211+0x0/0x40 [ 47.619481] ... acquired at: [ 47.622680] _raw_spin_lock+0x2f/0x40 [ 47.626649] io_submit_one+0xef2/0x2eb0 [ 47.630795] __x64_sys_io_submit+0x1aa/0x520 [ 47.635356] do_syscall_64+0xfd/0x620 [ 47.639310] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 47.644806] [ 47.646427] -> (&(&ctx->ctx_lock)->rlock){..-.} ops: 2 { [ 47.651863] IN-SOFTIRQ-W at: [ 47.655131] lock_acquire+0x16f/0x3f0 [ 47.660573] _raw_spin_lock_irq+0x60/0x80 [ 47.666355] free_ioctx_users+0x2d/0x490 [ 47.672049] percpu_ref_switch_to_atomic_rcu+0x407/0x540 [ 47.679153] rcu_process_callbacks+0xba0/0x1a30 [ 47.685472] __do_softirq+0x25c/0x921 [ 47.690903] irq_exit+0x180/0x1d0 [ 47.695987] smp_apic_timer_interrupt+0x13b/0x550 [ 47.702468] apic_timer_interrupt+0xf/0x20 [ 47.708341] native_safe_halt+0xe/0x10 [ 47.713876] arch_cpu_idle+0xa/0x10 [ 47.719134] default_idle_call+0x36/0x90 [ 47.724829] do_idle+0x377/0x560 [ 47.729823] cpu_startup_entry+0xc8/0xe0 [ 47.735517] start_secondary+0x3e8/0x5b0 [ 47.741209] secondary_startup_64+0xa4/0xb0 [ 47.747179] INITIAL USE at: [ 47.750360] lock_acquire+0x16f/0x3f0 [ 47.755717] _raw_spin_lock_irq+0x60/0x80 [ 47.761408] io_submit_one+0xead/0x2eb0 [ 47.766925] __x64_sys_io_submit+0x1aa/0x520 [ 47.772878] do_syscall_64+0xfd/0x620 [ 47.778221] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 47.784950] } [ 47.786733] ... key at: [] __key.50211+0x0/0x40 [ 47.793458] ... acquired at: [ 47.796546] mark_lock+0x420/0x1370 [ 47.800328] __lock_acquire+0xc62/0x49c0 [ 47.804540] lock_acquire+0x16f/0x3f0 [ 47.808497] _raw_spin_lock_irq+0x60/0x80 [ 47.812801] free_ioctx_users+0x2d/0x490 [ 47.817028] percpu_ref_switch_to_atomic_rcu+0x407/0x540 [ 47.822632] rcu_process_callbacks+0xba0/0x1a30 [ 47.827456] __do_softirq+0x25c/0x921 [ 47.831409] irq_exit+0x180/0x1d0 [ 47.835015] smp_apic_timer_interrupt+0x13b/0x550 [ 47.840011] apic_timer_interrupt+0xf/0x20 [ 47.844401] native_safe_halt+0xe/0x10 [ 47.848445] arch_cpu_idle+0xa/0x10 [ 47.852225] default_idle_call+0x36/0x90 [ 47.856439] do_idle+0x377/0x560 [ 47.859959] cpu_startup_entry+0xc8/0xe0 [ 47.864176] start_secondary+0x3e8/0x5b0 [ 47.868391] secondary_startup_64+0xa4/0xb0 [ 47.872874] [ 47.874478] [ 47.874478] stack backtrace: [ 47.878958] CPU: 1 PID: 0 Comm: swapper/1 Not tainted 4.19.69 #43 [ 47.885166] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 47.894501] Call Trace: [ 47.897080] [ 47.906509] dump_stack+0x172/0x1f0 [ 47.910126] print_irq_inversion_bug.part.0+0x2c0/0x2cd [ 47.915486] check_usage_forwards.cold+0x20/0x29 [ 47.920220] ? check_usage_backwards+0x340/0x340 [ 47.924959] ? save_stack_trace+0x1a/0x20 [ 47.929095] ? save_trace+0xe0/0x290 [ 47.932790] mark_lock+0x420/0x1370 [ 47.937546] ? check_usage_backwards+0x340/0x340 [ 47.942286] __lock_acquire+0xc62/0x49c0 [ 47.946346] ? mark_held_locks+0x100/0x100 [ 47.950568] ? mark_held_locks+0x100/0x100 [ 47.955400] ? __wake_up_common_lock+0xfe/0x190 [ 47.960327] ? mark_held_locks+0x100/0x100 [ 47.964540] ? __wake_up_common_lock+0xfe/0x190 [ 47.969193] ? _raw_spin_unlock_irqrestore+0x6b/0xe0 [ 47.974277] ? lockdep_hardirqs_on+0x19b/0x5d0 [ 47.978839] ? trace_hardirqs_on+0x67/0x220 [ 47.983154] ? kasan_check_read+0x11/0x20 [ 47.987279] lock_acquire+0x16f/0x3f0 [ 47.991063] ? free_ioctx_users+0x2d/0x490 [ 47.995277] _raw_spin_lock_irq+0x60/0x80 [ 47.999419] ? free_ioctx_users+0x2d/0x490 [ 48.003635] free_ioctx_users+0x2d/0x490 [ 48.007679] ? rcu_dynticks_curr_cpu_in_eqs+0x51/0xb0 [ 48.012875] percpu_ref_switch_to_atomic_rcu+0x407/0x540 [ 48.018414] ? percpu_ref_exit+0xd0/0xd0 [ 48.022456] rcu_process_callbacks+0xba0/0x1a30 [ 48.027106] ? __rcu_read_unlock+0x170/0x170 [ 48.031495] __do_softirq+0x25c/0x921 [ 48.035277] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 48.040791] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 48.046341] irq_exit+0x180/0x1d0 [ 48.049779] smp_apic_timer_interrupt+0x13b/0x550 [ 48.054602] apic_timer_interrupt+0xf/0x20 [ 48.058812] [ 48.061037] RIP: 0010:native_safe_halt+0xe/0x10 [ 48.065688] Code: ff ff 48 89 df e8 02 2c ae fa eb 82 e9 07 00 00 00 0f 00 2d 84 1e 54 00 f4 c3 66 90 e9 07 00 00 00 0f 00 2d 74 1e 54 00 fb f4 90 55 48 89 e5 41 57 41 56 41 55 41 54 53 e8 4e 0e 66 fa e8 09 [ 48.084590] RSP: 0018:ffff8880aa27fd00 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff13 [ 48.092286] RAX: 1ffffffff10e48c4 RBX: ffff8880aa2703c0 RCX: 0000000000000000 [ 48.100708] RDX: dffffc0000000000 RSI: 0000000000000001 RDI: ffff8880aa270c3c [ 48.107961] RBP: ffff8880aa27fd30 R08: ffff8880aa2703c0 R09: 0000000000000000 [ 48.115224] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000001 [ 48.122473] R13: ffffffff88724610 R14: 0000000000000001 R15: 0000000000000000 [ 48.129739] ? default_idle+0x4e/0x320 [ 48.133611] arch_cpu_idle+0xa/0x10 [ 48.137226] defau