[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[ 19.603093] random: sshd: uninitialized urandom read (32 bytes read) [?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 23.401817] random: sshd: uninitialized urandom read (32 bytes read) [ 23.789222] random: sshd: uninitialized urandom read (32 bytes read) [ 24.507130] random: sshd: uninitialized urandom read (32 bytes read) [ 24.664190] random: sshd: uninitialized urandom read (32 bytes read) Warning: Permanently added '10.128.10.22' (ECDSA) to the list of known hosts. [ 30.248378] random: sshd: uninitialized urandom read (32 bytes read) [ 32.977901] [ 32.979591] ================================ [ 32.983971] WARNING: inconsistent lock state [ 32.988351] 4.17.0-rc2+ #14 Not tainted [ 32.992297] -------------------------------- [ 32.996678] inconsistent {HARDIRQ-ON-W} -> {IN-HARDIRQ-W} usage. [ 33.002797] syzkaller151432/4525 [HC1[1]:SC0[0]:HE0:SE1] takes: [ 33.008826] (ptrval) (fs_reclaim){?.+.}, at: fs_reclaim_acquire.part.82+0x0/0x30 [ 33.017042] {HARDIRQ-ON-W} state was registered at: [ 33.022044] lock_acquire+0x1dc/0x520 [ 33.025907] fs_reclaim_acquire.part.82+0x24/0x30 [ 33.030808] fs_reclaim_acquire+0x14/0x20 [ 33.035017] kmem_cache_alloc_node_trace+0x39/0x770 [ 33.040095] alloc_worker+0xbd/0x2e0 [ 33.043872] init_rescuer.part.25+0x1f/0x190 [ 33.048343] workqueue_init+0x51f/0x7d0 [ 33.052377] kernel_init_freeable+0x2ad/0x58e [ 33.056934] kernel_init+0x11/0x1b3 [ 33.060621] ret_from_fork+0x3a/0x50 [ 33.064394] irq event stamp: 927456 [ 33.067999] hardirqs last enabled at (927455): [] _raw_spin_unlock_irq+0x27/0x70 [ 33.077157] hardirqs last disabled at (927456): [] interrupt_entry+0xb5/0xf0 [ 33.085899] softirqs last enabled at (927430): [] wb_queue_work+0x302/0x6e0 [ 33.094631] softirqs last disabled at (927426): [] wb_queue_work+0x117/0x6e0 [ 33.103357] [ 33.103357] other info that might help us debug this: [ 33.109997] Possible unsafe locking scenario: [ 33.109997] [ 33.116025] CPU0 [ 33.118580] ---- [ 33.121133] lock(fs_reclaim); [ 33.124388] [ 33.127113] lock(fs_reclaim); [ 33.130537] [ 33.130537] *** DEADLOCK *** [ 33.130537] [ 33.136572] 1 lock held by syzkaller151432/4525: [ 33.141296] #0: (ptrval) (&type->s_umount_key#29){++++}, at: __x64_sys_syncfs+0xb6/0x120 [ 33.150291] [ 33.150291] stack backtrace: [ 33.154763] CPU: 0 PID: 4525 Comm: syzkaller151432 Not tainted 4.17.0-rc2+ #14 [ 33.162094] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 33.171419] Call Trace: [ 33.173974] [ 33.176104] dump_stack+0x1b9/0x294 [ 33.179706] ? dump_stack_print_info.cold.2+0x52/0x52 [ 33.184872] ? print_lock+0xd1/0xd6 [ 33.188475] ? vprintk_func+0x81/0xe7 [ 33.192260] print_usage_bug.cold.59+0x320/0x41a [ 33.196993] ? save_stack_trace+0x1a/0x20 [ 33.201115] mark_lock+0x1034/0x19e0 [ 33.204802] ? check_usage_backwards+0x3a0/0x3a0 [ 33.209531] ? print_usage_bug+0xc0/0xc0 [ 33.213566] ? save_trace+0xe0/0x290 [ 33.217253] ? print_usage_bug+0xc0/0xc0 [ 33.221289] ? mark_lock+0xafe/0x19e0 [ 33.225062] ? check_usage_backwards+0x3a0/0x3a0 [ 33.229792] ? print_usage_bug+0xc0/0xc0 [ 33.233830] ? scsi_mq_uninit_cmd+0x30/0x30 [ 33.238127] __lock_acquire+0x1595/0x5140 [ 33.242251] ? __lock_acquire+0x7f5/0x5140 [ 33.246462] ? find_held_lock+0x36/0x1c0 [ 33.250503] ? debug_check_no_locks_freed+0x310/0x310 [ 33.255670] ? debug_check_no_locks_freed+0x310/0x310 [ 33.260834] ? debug_check_no_locks_freed+0x310/0x310 [ 33.266000] ? lock_downgrade+0x8e0/0x8e0 [ 33.270126] ? sha_transform+0x26/0x4449 [ 33.274165] ? kasan_check_read+0x11/0x20 [ 33.278292] ? do_raw_spin_unlock+0x9e/0x2e0 [ 33.282688] ? do_raw_spin_trylock+0x1b0/0x1b0 [ 33.287245] ? memset+0x31/0x40 [ 33.290503] ? memzero_explicit+0xe/0x10 [ 33.294543] ? extract_buf+0x3a3/0x4c0 [ 33.298408] ? graph_lock+0x170/0x170 [ 33.302187] ? crng_fast_load+0x3b0/0x3b0 [ 33.306320] ? graph_lock+0x170/0x170 [ 33.310096] ? account.constprop.30+0x34e/0x700 [ 33.314761] lock_acquire+0x1dc/0x520 [ 33.318562] ? bad_range+0x160/0x160 [ 33.322271] ? lock_release+0xa10/0xa10 [ 33.326221] ? lock_downgrade+0x8e0/0x8e0 [ 33.330348] ? lock_release+0xa10/0xa10 [ 33.334299] ? lock_downgrade+0x8e0/0x8e0 [ 33.338428] fs_reclaim_acquire.part.82+0x24/0x30 [ 33.343247] ? bad_range+0x160/0x160 [ 33.346935] fs_reclaim_acquire+0x14/0x20 [ 33.351061] __kmalloc+0x45/0x760 [ 33.354490] ? trace_hardirqs_off+0xd/0x10 [ 33.358705] ? _raw_write_unlock_irqrestore+0x63/0xc0 [ 33.363872] ? crng_reseed+0x427/0x920 [ 33.367735] crng_reseed+0x427/0x920 [ 33.371429] ? _extract_entropy.constprop.32+0x150/0x150 [ 33.376855] ? __lock_is_held+0xb5/0x140 [ 33.380894] credit_entropy_bits+0x98d/0xa30 [ 33.385280] ? add_interrupt_randomness+0x494/0x860 [ 33.390273] ? crng_reseed+0x920/0x920 [ 33.394137] ? lock_downgrade+0x8e0/0x8e0 [ 33.398261] ? __mix_pool_bytes+0xde/0x400 [ 33.402475] ? kasan_check_read+0x11/0x20 [ 33.406602] ? do_raw_spin_unlock+0x9e/0x2e0 [ 33.410988] ? do_raw_spin_trylock+0x1b0/0x1b0 [ 33.415551] ? __handle_irq_event_percpu+0x34d/0xad0 [ 33.420632] add_interrupt_randomness+0x494/0x860 [ 33.425451] ? extract_entropy.constprop.29+0x490/0x490 [ 33.430791] ? lock_downgrade+0x8e0/0x8e0 [ 33.434916] ? handle_edge_irq+0x30/0x870 [ 33.439043] ? lock_downgrade+0x8e0/0x8e0 [ 33.443178] handle_irq_event_percpu+0xf9/0x1c0 [ 33.447825] ? do_raw_spin_trylock+0x1b0/0x1b0 [ 33.452383] ? __handle_irq_event_percpu+0xad0/0xad0 [ 33.457465] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 33.462978] handle_irq_event+0xa7/0x135 [ 33.467021] handle_edge_irq+0x20f/0x870 [ 33.471066] handle_irq+0x18c/0x2e7 [ 33.474671] do_IRQ+0x78/0x190 [ 33.477841] common_interrupt+0xf/0xf [ 33.481614] [ 33.483829] RIP: 0010:_raw_spin_unlock_irq+0x56/0x70 [ 33.488903] RSP: 0018:ffff8801ab34f6b0 EFLAGS: 00000282 ORIG_RAX: ffffffffffffffda [ 33.496590] RAX: dffffc0000000000 RBX: ffff8801dae2c580 RCX: 1ffff10035f7393b [ 33.503839] RDX: 1ffffffff11a315f RSI: ffff8801afb9c9b8 RDI: ffffffff88d18af8 [ 33.511088] RBP: ffff8801ab34f6b8 R08: ffff8801afb9c9b8 R09: 0000000000000006 [ 33.518336] R10: ffff8801afb9c180 R11: 0000000000000000 R12: ffff8801afb9c180 [ 33.525582] R13: ffff8801d2136600 R14: ffff8801b0312c80 R15: ffff8801afb9c180 [ 33.532842] finish_task_switch+0x1ca/0x810 [ 33.537140] ? finish_task_switch+0x182/0x810 [ 33.541617] ? preempt_notifier_register+0x1e0/0x1e0 [ 33.546716] ? lock_repin_lock+0x410/0x410 [ 33.550932] __schedule+0x809/0x1e30 [ 33.554622] ? rcu_is_watching+0x85/0x140 [ 33.558746] ? __sched_text_start+0x8/0x8 [ 33.562873] ? __lock_is_held+0xb5/0x140 [ 33.566913] ? check_same_owner+0x320/0x320 [ 33.571213] preempt_schedule_common+0x22/0x60 [ 33.575772] _cond_resched+0x1d/0x30 [ 33.579463] wait_for_completion_io+0xa7/0x870 [ 33.584028] ? bit_wait_io_timeout+0x200/0x200 [ 33.588588] ? submit_bio+0xba/0x460 [ 33.592278] ? submit_bio+0xba/0x460 [ 33.595968] ? generic_make_request+0x1510/0x1510 [ 33.600793] ? init_wait_entry+0x1b0/0x1b0 [ 33.605005] ? lock_downgrade+0x8e0/0x8e0 [ 33.609140] submit_bio_wait+0x13c/0x1e0 [ 33.613182] ? submit_bio_wait_endio+0x40/0x40 [ 33.617743] ? kasan_check_write+0x14/0x20 [ 33.621953] ? do_raw_write_lock+0xbd/0x1b0 [ 33.626264] blkdev_issue_flush+0x226/0x320 [ 33.630563] ext4_sync_fs+0x604/0xaf0 [ 33.634342] ? ext4_statfs+0xe40/0xe40 [ 33.638217] ? delete_from_page_cache_batch+0xf70/0xf70 [ 33.643560] ? filemap_flush+0x23/0x30 [ 33.647421] ? ext4_statfs+0xe40/0xe40 [ 33.651290] sync_filesystem+0x265/0x310 [ 33.655330] ? sync_fs_one_sb+0x100/0x100 [ 33.659455] ? filp_open+0x80/0x80 [ 33.662977] ? syscall_slow_exit_work+0x4f0/0x4f0 [ 33.667798] __x64_sys_syncfs+0xbe/0x120 [ 33.671836] do_syscall_64+0x1b1/0x800 [ 33.675699] ? syscall_slow_exit_work+0x4f0/0x4f0 [ 33.680520] ? syscall_return_slowpath+0x5c0/0x5c0 [ 33.685428] ? syscall_return_slowpath+0x30f/0x5c0 [ 33.690333] ? entry_SYSCALL_64_after_hwframe+0x59/0xbe [ 33.695673] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 33.700494] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 33.705658] RIP: 0033:0x440069 [ 33.708826] RSP: 002b:00007ffd92dff978 EFLAGS: 00000246 ORIG_RAX: 0000000000000132 [ 33.716509] RAX: ffffffffffffffda RBX: 00007ffd92dff980 RCX: 0000000000440069 [ 33.723756] RDX: 0000000000400ae0 RSI: ffffffffffffffff RDI: 00000000000003ff [ 33.731001] RBP: 0000000020000380 R08: 000000000000000f R09: 65732f636f72702f [ 33.738254] R10: 0000000000000000 R11: 0000000000000246 R12: 00000000004a1528 [ 33.745498] R13: 00000000004a15f4 R14: 00000000000077f0 R15: 0000000000000000 [ 33.752752] BUG: sleeping function called from invalid context at mm/slab.h:421 [ 33.760178] in_atomic(): 1, irqs_disabled(): 1, pid: 4525, name: syzkaller151432 [ 33.767683] INFO: lockdep is turned off. [ 33.771718] irq event stamp: 927456 [ 33.775328] hardirqs last enabled at (927455): [] _raw_spin_unlock_irq+0x27/0x70 [ 33.784490] hardirqs last disabled at (927456): [] interrupt_entry+0xb5/0xf0 [ 33.793219] softirqs last enabled at (927430): [] wb_queue_work+0x302/0x6e0 [ 33.801946] softirqs last disabled at (927426): [] wb_queue_work+0x117/0x6e0 [ 33.810675] CPU: 0 PID: 4525 Comm: syzkaller151432 Not tainted 4.17.0-rc2+ #14 [ 33.818012] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 33.827355] Call Trace: [ 33.829914] [ 33.832051] dump_stack+0x1b9/0x294 [ 33.835657] ? dump_stack_print_info.cold.2+0x52/0x52 [ 33.840823] ? fs_reclaim_acquire+0x20/0x20 [ 33.845123] ? wb_queue_work+0x117/0x6e0 [ 33.849162] ? wb_queue_work+0x117/0x6e0 [ 33.853202] ___might_sleep.cold.87+0x11f/0x13a [ 33.857847] ? check_same_owner+0x320/0x320 [ 33.862149] ? lock_release+0xa10/0xa10 [ 33.866104] __might_sleep+0x95/0x190 [ 33.869894] __kmalloc+0x2b9/0x760 [ 33.873413] ? trace_hardirqs_off+0xd/0x10 [ 33.877629] ? _raw_write_unlock_irqrestore+0x63/0xc0 [ 33.882798] ? crng_reseed+0x427/0x920 [ 33.886663] crng_reseed+0x427/0x920 [ 33.890354] ? _extract_entropy.constprop.32+0x150/0x150 [ 33.895783] ? __lock_is_held+0xb5/0x140 [ 33.899822] credit_entropy_bits+0x98d/0xa30 [ 33.904210] ? add_interrupt_randomness+0x494/0x860 [ 33.909212] ? crng_reseed+0x920/0x920 [ 33.913077] ? lock_downgrade+0x8e0/0x8e0 [ 33.917212] ? __mix_pool_bytes+0xde/0x400 [ 33.921426] ? kasan_check_read+0x11/0x20 [ 33.925553] ? do_raw_spin_unlock+0x9e/0x2e0 [ 33.929938] ? do_raw_spin_trylock+0x1b0/0x1b0 [ 33.934498] ? __handle_irq_event_percpu+0x34d/0xad0 [ 33.939581] add_interrupt_randomness+0x494/0x860 [ 33.944403] ? extract_entropy.constprop.29+0x490/0x490 [ 33.949745] ? lock_downgrade+0x8e0/0x8e0 [ 33.953871] ? handle_edge_irq+0x30/0x870 [ 33.957995] ? lock_downgrade+0x8e0/0x8e0 [ 33.962129] handle_irq_event_percpu+0xf9/0x1c0 [ 33.966776] ? do_raw_spin_trylock+0x1b0/0x1b0 [ 33.971336] ? __handle_irq_event_percpu+0xad0/0xad0 [ 33.976418] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 33.981933] handle_irq_event+0xa7/0x135 [ 33.985984] handle_edge_irq+0x20f/0x870 [ 33.990031] handle_irq+0x18c/0x2e7 [ 33.993643] do_IRQ+0x78/0x190 [ 33.996813] common_interrupt+0xf/0xf [ 34.000587] [ 34.002808] RIP: 0010:_raw_spin_unlock_irq+0x56/0x70 [ 34.007886] RSP: 0018:ffff8801ab34f6b0 EFLAGS: 00000282 ORIG_RAX: ffffffffffffffda [ 34.015583] RAX: dffffc0000000000 RBX: ffff8801dae2c580 RCX: 1ffff10035f7393b [ 34.022832] RDX: 1ffffffff11a315f RSI: ffff8801afb9c9b8 RDI: ffffffff88d18af8 [ 34.030082] RBP: ffff8801ab34f6b8 R08: ffff8801afb9c9b8 R09: 0000000000000006 [ 34.037329] R10: ffff8801afb9c180 R11: 0000000000000000 R12: ffff8801afb9c180 [ 34.044576] R13: ffff8801d2136600 R14: ffff8801b0312c80 R15: ffff8801afb9c180 [ 34.051837] finish_task_switch+0x1ca/0x810 [ 34.056138] ? finish_task_switch+0x182/0x810 [ 34.060615] ? preempt_notifier_register+0x1e0/0x1e0 [ 34.065697] ? lock_repin_lock+0x410/0x410 [ 34.069915] __schedule+0x809/0x1e30 [ 34.073607] ? rcu_is_watching+0x85/0x140 [ 34.077733] ? __sched_text_start+0x8/0x8 [ 34.081862] ? __lock_is_held+0xb5/0x140 [ 34.085908] ? check_same_owner+0x320/0x320 [ 34.090211] preempt_schedule_common+0x22/0x60 [ 34.094773] _cond_resched+0x1d/0x30 [ 34.098465] wait_for_completion_io+0xa7/0x870 [ 34.103032] ? bit_wait_io_timeout+0x200/0x200 [ 34.107594] ? submit_bio+0xba/0x460 [ 34.111295] ? submit_bio+0xba/0x460 [ 34.114986] ? generic_make_request+0x1510/0x1510 [ 34.119808] ? init_wait_entry+0x1b0/0x1b0 [ 34.124029] ? lock_downgrade+0x8e0/0x8e0 [ 34.128167] submit_bio_wait+0x13c/0x1e0 [ 34.132204] ? submit_bio_wait_endio+0x40/0x40 [ 34.136765] ? kasan_check_write+0x14/0x20 [ 34.140976] ? do_raw_write_lock+0xbd/0x1b0 [ 34.145278] blkdev_issue_flush+0x226/0x320 [ 34.149579] ext4_sync_fs+0x604/0xaf0 [ 34.153357] ? ext4_statfs+0xe40/0xe40 [ 34.157223] ? delete_from_page_cache_batch+0xf70/0xf70 [ 34.162567] ? filemap_flush+0x23/0x30 [ 34.166431] ? ext4_statfs+0xe40/0xe40 [ 34.170295] sync_filesystem+0x265/0x310 [ 34.174334] ? sync_fs_one_sb+0x100/0x100 [ 34.178460] ? filp_open+0x80/0x80 [ 34.181978] ? syscall_slow_exit_work+0x4f0/0x4f0 [ 34.186801] __x64_sys_syncfs+0xbe/0x120 [ 34.190845] do_syscall_64+0x1b1/0x800 [ 34.194709] ? syscall_slow_exit_work+0x4f0/0x4f0 [ 34.199530] ? syscall_return_slowpath+0x5c0/0x5c0 [ 34.204439] ? syscall_return_slowpath+0x30f/0x5c0 [ 34.209348] ? entry_SYSCALL_64_after_hwframe+0x59/0xbe [ 34.214690] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 34.219512] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 34.224677] RIP: 0033:0x440069 [ 34.227842] RSP: 002b:00007ffd92dff978 EFLAGS: 00000246 ORIG_RAX: 0000000000000132 [ 34.235526] RAX: ffffffffffffffda RBX: 00007ffd92dff980 RCX: 0000000000440069 [ 34.242773] RDX: 0000000000400ae0 RSI: ffffffffffffffff RDI: 00000000000003ff [ 34.250022] RBP: 0000000020000380 R08: 000000000000000f R09: 65732f636f72702f [ 34.257291] R10: 0000000000000000 R11: 0000000000000246 R12: 00000000004a1528 [ 34.264536] R13: 00000000004a15f4 R14: 00000000000077f0 R15: 0000000000000000 [ 34.271814] random: crng init done