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. [ 30.824856] audit: type=1800 audit(1540620595.400:33): pid=5531 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=2432 res=0 [ 30.846569] audit: type=1800 audit(1540620595.400:34): pid=5531 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=2423 res=0 Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 37.645469] audit: type=1400 audit(1540620602.220:35): avc: denied { map } for pid=5710 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 '10.128.0.38' (ECDSA) to the list of known hosts. [ 102.432151] audit: type=1400 audit(1540620667.010:36): avc: denied { map } for pid=5724 comm="syz-executor781" path="/root/syz-executor781272618" dev="sda1" ino=1426 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:object_r:user_home_t:s0 tclass=file permissive=1 [ 102.467772] IPVS: ftp: loaded support on port[0] = 21 executing program [ 102.497205] audit: type=1400 audit(1540620667.070:37): avc: denied { associate } for pid=5725 comm="syz-executor781" name="syz0" scontext=unconfined_u:object_r:unlabeled_t:s0 tcontext=system_u:object_r:unlabeled_t:s0 tclass=filesystem permissive=1 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 153.852097] [ 153.853917] ===================================================== [ 153.860136] WARNING: SOFTIRQ-safe -> SOFTIRQ-unsafe lock order detected [ 153.866868] 4.19.0+ #84 Not tainted [ 153.870472] ----------------------------------------------------- [ 153.876696] syz-executor781/7254 [HC0[0]:SC0[0]:HE0:SE1] is trying to acquire: [ 153.884043] 00000000e70e96f7 (&ctx->fd_wqh){+.+.}, at: aio_poll+0x760/0x1420 [ 153.891227] [ 153.891227] and this task is already holding: [ 153.897224] 000000009957d7d7 (&(&ctx->ctx_lock)->rlock){..-.}, at: aio_poll+0x738/0x1420 [ 153.905478] which would create a new lock dependency: [ 153.910647] (&(&ctx->ctx_lock)->rlock){..-.} -> (&ctx->fd_wqh){+.+.} [ 153.917224] [ 153.917224] but this new dependency connects a SOFTIRQ-irq-safe lock: [ 153.925272] (&(&ctx->ctx_lock)->rlock){..-.} [ 153.925279] [ 153.925279] ... which became SOFTIRQ-irq-safe at: [ 153.936055] lock_acquire+0x1ed/0x520 [ 153.939931] _raw_spin_lock_irq+0x61/0x80 [ 153.944156] free_ioctx_users+0xbc/0x710 [ 153.948296] percpu_ref_switch_to_atomic_rcu+0x563/0x730 [ 153.953818] rcu_process_callbacks+0x100a/0x1ac0 [ 153.958647] __do_softirq+0x308/0xb7e [ 153.962580] irq_exit+0x17f/0x1c0 [ 153.966113] smp_apic_timer_interrupt+0x1cb/0x760 [ 153.971031] apic_timer_interrupt+0xf/0x20 [ 153.975341] native_safe_halt+0x6/0x10 [ 153.979298] default_idle+0xbf/0x490 [ 153.983082] arch_cpu_idle+0x10/0x20 [ 153.986864] default_idle_call+0x6d/0x90 [ 153.991004] do_idle+0x49b/0x5c0 [ 153.994455] cpu_startup_entry+0x18/0x20 [ 153.998600] start_secondary+0x487/0x5f0 [ 154.002731] secondary_startup_64+0xa4/0xb0 [ 154.007115] [ 154.007115] to a SOFTIRQ-irq-unsafe lock: [ 154.012717] (&ctx->fd_wqh){+.+.} [ 154.012724] [ 154.012724] ... which became SOFTIRQ-irq-unsafe at: [ 154.022624] ... [ 154.022640] lock_acquire+0x1ed/0x520 [ 154.028382] _raw_spin_lock+0x2d/0x40 [ 154.032267] userfaultfd_ctx_read+0x2e4/0x2180 [ 154.037099] userfaultfd_read+0x1e2/0x2c0 [ 154.041325] __vfs_read+0x117/0x9b0 [ 154.045024] vfs_read+0x17f/0x3c0 [ 154.048548] ksys_read+0x101/0x260 [ 154.052160] __x64_sys_read+0x73/0xb0 [ 154.056033] do_syscall_64+0x1b9/0x820 [ 154.059999] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 154.065259] [ 154.065259] other info that might help us debug this: [ 154.065259] [ 154.073389] Possible interrupt unsafe locking scenario: [ 154.073389] [ 154.080304] CPU0 CPU1 [ 154.084956] ---- ---- [ 154.089607] lock(&ctx->fd_wqh); [ 154.093047] local_irq_disable(); [ 154.099084] lock(&(&ctx->ctx_lock)->rlock); [ 154.106080] lock(&ctx->fd_wqh); [ 154.112030] [ 154.114818] lock(&(&ctx->ctx_lock)->rlock); [ 154.119474] [ 154.119474] *** DEADLOCK *** [ 154.119474] [ 154.125567] 1 lock held by syz-executor781/7254: [ 154.130312] #0: 000000009957d7d7 (&(&ctx->ctx_lock)->rlock){..-.}, at: aio_poll+0x738/0x1420 [ 154.138977] [ 154.138977] the dependencies between SOFTIRQ-irq-safe lock and the holding lock: [ 154.147976] -> (&(&ctx->ctx_lock)->rlock){..-.} { [ 154.152805] IN-SOFTIRQ-W at: [ 154.156076] lock_acquire+0x1ed/0x520 [ 154.161515] _raw_spin_lock_irq+0x61/0x80 [ 154.167297] free_ioctx_users+0xbc/0x710 [ 154.172995] percpu_ref_switch_to_atomic_rcu+0x563/0x730 [ 154.180084] rcu_process_callbacks+0x100a/0x1ac0 [ 154.186477] __do_softirq+0x308/0xb7e [ 154.191912] irq_exit+0x17f/0x1c0 [ 154.197003] smp_apic_timer_interrupt+0x1cb/0x760 [ 154.203493] apic_timer_interrupt+0xf/0x20 [ 154.209369] native_safe_halt+0x6/0x10 [ 154.214987] default_idle+0xbf/0x490 [ 154.220338] arch_cpu_idle+0x10/0x20 [ 154.225739] default_idle_call+0x6d/0x90 [ 154.231443] do_idle+0x49b/0x5c0 [ 154.236457] cpu_startup_entry+0x18/0x20 [ 154.242154] start_secondary+0x487/0x5f0 [ 154.247849] secondary_startup_64+0xa4/0xb0 [ 154.253797] INITIAL USE at: [ 154.256975] lock_acquire+0x1ed/0x520 [ 154.262326] _raw_spin_lock_irq+0x61/0x80 [ 154.268130] free_ioctx_users+0xbc/0x710 [ 154.273749] percpu_ref_switch_to_atomic_rcu+0x563/0x730 [ 154.280754] rcu_process_callbacks+0x100a/0x1ac0 [ 154.287073] __do_softirq+0x308/0xb7e [ 154.292490] irq_exit+0x17f/0x1c0 [ 154.297501] smp_apic_timer_interrupt+0x1cb/0x760 [ 154.303947] apic_timer_interrupt+0xf/0x20 [ 154.309743] native_safe_halt+0x6/0x10 [ 154.315183] default_idle+0xbf/0x490 [ 154.320450] arch_cpu_idle+0x10/0x20 [ 154.325724] default_idle_call+0x6d/0x90 [ 154.331346] do_idle+0x49b/0x5c0 [ 154.336278] cpu_startup_entry+0x18/0x20 [ 154.341894] start_secondary+0x487/0x5f0 [ 154.347510] secondary_startup_64+0xa4/0xb0 [ 154.353382] } [ 154.355186] ... key at: [] __key.50623+0x0/0x40 [ 154.361921] ... acquired at: [ 154.365021] lock_acquire+0x1ed/0x520 [ 154.368987] _raw_spin_lock+0x2d/0x40 [ 154.372947] aio_poll+0x760/0x1420 [ 154.376650] io_submit_one+0xa49/0xf80 [ 154.380695] __x64_sys_io_submit+0x1b7/0x580 [ 154.385396] do_syscall_64+0x1b9/0x820 [ 154.389457] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 154.394805] [ 154.396424] [ 154.396424] the dependencies between the lock to be acquired [ 154.396430] and SOFTIRQ-irq-unsafe lock: [ 154.407923] -> (&ctx->fd_wqh){+.+.} { [ 154.411720] HARDIRQ-ON-W at: [ 154.414999] lock_acquire+0x1ed/0x520 [ 154.420437] _raw_spin_lock+0x2d/0x40 [ 154.425883] userfaultfd_ctx_read+0x2e4/0x2180 [ 154.432105] userfaultfd_read+0x1e2/0x2c0 [ 154.437993] __vfs_read+0x117/0x9b0 [ 154.443273] vfs_read+0x17f/0x3c0 [ 154.448424] ksys_read+0x101/0x260 [ 154.453610] __x64_sys_read+0x73/0xb0 [ 154.459050] do_syscall_64+0x1b9/0x820 [ 154.464581] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 154.471403] SOFTIRQ-ON-W at: [ 154.475027] lock_acquire+0x1ed/0x520 [ 154.480520] _raw_spin_lock+0x2d/0x40 [ 154.485957] userfaultfd_ctx_read+0x2e4/0x2180 [ 154.492226] userfaultfd_read+0x1e2/0x2c0 [ 154.498025] __vfs_read+0x117/0x9b0 [ 154.503292] vfs_read+0x17f/0x3c0 [ 154.508380] ksys_read+0x101/0x260 [ 154.513555] __x64_sys_read+0x73/0xb0 [ 154.518993] do_syscall_64+0x1b9/0x820 [ 154.524520] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 154.531343] INITIAL USE at: [ 154.534529] lock_acquire+0x1ed/0x520 [ 154.539928] _raw_spin_lock+0x2d/0x40 [ 154.545282] userfaultfd_ctx_read+0x2e4/0x2180 [ 154.551416] userfaultfd_read+0x1e2/0x2c0 [ 154.557113] __vfs_read+0x117/0x9b0 [ 154.562351] vfs_read+0x17f/0x3c0 [ 154.567355] ksys_read+0x101/0x260 [ 154.572444] __x64_sys_read+0x73/0xb0 [ 154.577792] do_syscall_64+0x1b9/0x820 [ 154.583235] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 154.590083] } [ 154.591878] ... key at: [] __key.44253+0x0/0x40 [ 154.598611] ... acquired at: [ 154.601715] lock_acquire+0x1ed/0x520 [ 154.605681] _raw_spin_lock+0x2d/0x40 [ 154.609710] aio_poll+0x760/0x1420 [ 154.613765] io_submit_one+0xa49/0xf80 [ 154.617814] __x64_sys_io_submit+0x1b7/0x580 [ 154.622384] do_syscall_64+0x1b9/0x820 [ 154.626490] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 154.631849] [ 154.633459] [ 154.633459] stack backtrace: [ 154.638079] CPU: 0 PID: 7254 Comm: syz-executor781 Not tainted 4.19.0+ #84 [ 154.645075] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 154.654465] Call Trace: [ 154.657058] dump_stack+0x244/0x39d [ 154.660677] ? dump_stack_print_info.cold.1+0x20/0x20 [ 154.665858] ? print_shortest_lock_dependencies.cold.55+0x18e/0x211 [ 154.672307] ? vprintk_func+0x85/0x181 [ 154.676196] check_usage.cold.58+0x6d5/0xad1 [ 154.680597] ? check_usage_forwards+0x3d0/0x3d0 [ 154.685265] ? __lock_acquire+0x62f/0x4c20 [ 154.689507] ? lockdep_on+0x50/0x50 [ 154.693133] ? mark_held_locks+0x130/0x130 [ 154.697358] ? __lock_acquire+0x62f/0x4c20 [ 154.701577] ? do_raw_spin_unlock+0xa7/0x330 [ 154.705982] ? trace_event_raw_event_lock_acquire+0x440/0x440 [ 154.711865] __lock_acquire+0x238a/0x4c20 [ 154.715999] ? __lock_acquire+0x238a/0x4c20 [ 154.720324] ? mark_held_locks+0x130/0x130 [ 154.724548] ? zap_class+0x640/0x640 [ 154.728260] ? _raw_spin_unlock_irqrestore+0x82/0xd0 [ 154.733403] ? find_held_lock+0x36/0x1c0 [ 154.737464] ? add_wait_queue+0x1b9/0x2b0 [ 154.741602] ? _raw_spin_unlock_irqrestore+0x82/0xd0 [ 154.746708] ? _raw_spin_unlock_irqrestore+0x82/0xd0 [ 154.751813] ? lockdep_hardirqs_on+0x3bb/0x5b0 [ 154.756384] ? trace_hardirqs_on+0xbd/0x310 [ 154.760697] ? kasan_check_read+0x11/0x20 [ 154.764832] ? add_wait_queue+0x1b9/0x2b0 [ 154.768967] ? trace_hardirqs_off_caller+0x310/0x310 [ 154.774186] ? rcu_softirq_qs+0x20/0x20 [ 154.778155] ? _raw_spin_unlock_irqrestore+0x6d/0xd0 [ 154.783255] ? add_wait_queue+0x1b9/0x2b0 [ 154.787401] ? __wake_up_locked_key_bookmark+0x20/0x20 [ 154.792666] lock_acquire+0x1ed/0x520 [ 154.796461] ? aio_poll+0x760/0x1420 [ 154.800259] ? lock_release+0xa00/0xa00 [ 154.804229] ? kasan_check_read+0x11/0x20 [ 154.808374] ? do_raw_spin_lock+0x14f/0x350 [ 154.812683] ? __ia32_sys_eventfd+0x40/0x40 [ 154.816996] ? rwlock_bug.part.2+0x90/0x90 [ 154.821349] ? trace_hardirqs_on+0x310/0x310 [ 154.825747] ? __save_stack_trace+0x8d/0xf0 [ 154.830059] _raw_spin_lock+0x2d/0x40 [ 154.833848] ? aio_poll+0x760/0x1420 [ 154.837599] aio_poll+0x760/0x1420 [ 154.841141] ? free_ioctx_users+0x710/0x710 [ 154.845451] ? kmem_cache_alloc+0x12e/0x730 [ 154.849764] ? aio_setup_rw+0x170/0x170 [ 154.853727] ? find_held_lock+0x36/0x1c0 [ 154.857784] ? zap_class+0x640/0x640 [ 154.861485] ? zap_class+0x640/0x640 [ 154.865196] ? quarantine_reduce+0x14a/0x1a0 [ 154.869597] ? lock_downgrade+0x900/0x900 [ 154.873746] ? find_held_lock+0x36/0x1c0 [ 154.877798] ? __might_fault+0x12b/0x1e0 [ 154.881848] ? lock_downgrade+0x900/0x900 [ 154.885983] ? lock_release+0xa00/0xa00 [ 154.889943] ? perf_trace_sched_process_exec+0x860/0x860 [ 154.895383] ? kasan_check_read+0x11/0x20 [ 154.899520] ? rcu_dynticks_curr_cpu_in_eqs+0xa2/0x170 [ 154.904786] io_submit_one+0xa49/0xf80 [ 154.908659] ? io_submit_one+0xa49/0xf80 [ 154.912713] ? aio_poll+0x1420/0x1420 [ 154.916503] ? __might_fault+0x12b/0x1e0 [ 154.920553] ? lock_downgrade+0x900/0x900 [ 154.924753] ? perf_trace_sched_process_exec+0x860/0x860 [ 154.930201] __x64_sys_io_submit+0x1b7/0x580 [ 154.934596] ? __ia32_sys_io_destroy+0x580/0x580 [ 154.939343] ? trace_hardirqs_on+0xbd/0x310 [ 154.943716] ? entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 154.949081] ? trace_hardirqs_off_caller+0x310/0x310 [ 154.954168] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 154.959689] ? ksys_ioctl+0x81/0xd0 [ 154.963301] do_syscall_64+0x1b9/0x820 [ 154.967181] ? __ia32_sys_io_destroy+0x580/0x580 [ 154.971937] ? do_syscall_64+0x1b9/0x820 [ 154.975996] ? entry_SYSCALL_64_after_hwframe+0x3e/0xbe [ 154.981351] ? syscall_return_slowpath+0x5e0/0x5e0 [ 154.986278] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 154.991217] ? trace_hardirqs_on_caller+0x310/0x310 [ 154.996227] ? prepare_exit_to_usermode+0x3b0/0x3b0 [ 155.001244] ? prepare_exit_to_usermode+0x291/0x3b0 [ 155.006263] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 155.011149] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 155.016328] RIP: 0033:0x447dc9 [ 155.019510] Code: e8 9c ba 02 00 48 83 c4 18 c3 0f 1f 80 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 5b 07 fc ff c3 66 2e 0f 1f 84 00 00 00 00 [ 155.038402] RSP: 002b:00007fc840e69da8 EFLAGS: 00000293 ORIG_RAX: 00000000000000d1 [ 155.046102] RAX: ffffffffffffffda RBX: 00000000006e39e8 RCX: 0000000000447dc9 [ 155.053372] RDX: 0000000020000b00 RSI: 0000000000000001 RDI: 00007fc840e39000 [ 155.060634] RBP: 00000000006e39e0 R08: 0000000000000000 R09: 0000000000000000 [ 155.067945] R10: 0000000000000000 R11: 0000000000000293 R12: 00000000006e39ec [ 155.075210] R13: 702f74656e2f666c R14: 65732f636f72702f R15: 0000000000000000 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program