Enabling of bearer rejected, already enabled list_del corruption, ffffea0000f33bc8->next is LIST_POISON1 (dead000000000100) ------------[ cut here ]------------ kernel BUG at lib/list_debug.c:45! invalid opcode: 0000 [#1] PREEMPT SMP KASAN CPU: 1 PID: 7418 Comm: kworker/1:3 Not tainted 4.20.0+ #12 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 kobject: 'loop1' (00000000022d321d): kobject_uevent_env Workqueue: events cache_reap RIP: 0010:__list_del_entry_valid.cold+0x23/0x4f lib/list_debug.c:45 Code: e8 95 5d d7 fd 0f 0b 4c 89 f6 48 c7 c7 c0 b1 81 88 e8 84 5d d7 fd 0f 0b 4c 89 ea 4c 89 f6 48 c7 c7 00 b1 81 88 e8 70 5d d7 fd <0f> 0b 4c 89 e2 4c 89 f6 48 c7 c7 60 b1 81 88 e8 5c 5d d7 fd 0f 0b RSP: 0018:ffff8880898b7888 EFLAGS: 00010082 RAX: 000000000000004e RBX: ffffe8ffffd65bd0 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff81684ce6 RDI: ffffed1011316f03 RBP: ffff8880898b78a0 R08: 000000000000004e R09: ffffed1015ce5021 R10: ffffed1015ce5020 R11: ffff8880ae728107 R12: dead000000000200 R13: dead000000000100 R14: ffffea0000f33bc8 R15: ffffea0000f33bc8 FS: 0000000000000000(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000c42cbb8410 CR3: 0000000085594000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __list_del_entry include/linux/list.h:117 [inline] list_del include/linux/list.h:125 [inline] free_block+0xd8/0x250 mm/slab.c:3403 drain_array_locked+0x36/0x90 mm/slab.c:2195 drain_array+0x8c/0xb0 mm/slab.c:4009 cache_reap+0xf4/0x280 mm/slab.c:4050 process_one_work+0xd0c/0x1ce0 kernel/workqueue.c:2153 worker_thread+0x143/0x14a0 kernel/workqueue.c:2296 kthread+0x357/0x430 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352 Modules linked in: ====================================================== WARNING: possible circular locking dependency detected 4.20.0+ #12 Not tainted ------------------------------------------------------ kworker/1:3/7418 is trying to acquire lock: 000000006a76babf (console_owner){-.-.}, at: log_next kernel/printk/printk.c:492 [inline] 000000006a76babf (console_owner){-.-.}, at: console_unlock+0x4d3/0x11e0 kernel/printk/printk.c:2395 but task is already holding lock: 00000000adc514b9 (&(&parent->list_lock)->rlock){-.-.}, at: spin_lock_irq include/linux/spinlock.h:354 [inline] 00000000adc514b9 (&(&parent->list_lock)->rlock){-.-.}, at: drain_array+0x7a/0xb0 mm/slab.c:4008 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (&(&parent->list_lock)->rlock){-.-.}: __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2f/0x40 kernel/locking/spinlock.c:144 spin_lock include/linux/spinlock.h:329 [inline] cache_alloc_refill mm/slab.c:2994 [inline] ____cache_alloc mm/slab.c:3114 [inline] ____cache_alloc mm/slab.c:3097 [inline] __do_cache_alloc mm/slab.c:3336 [inline] slab_alloc mm/slab.c:3371 [inline] __do_kmalloc mm/slab.c:3707 [inline] __kmalloc+0x3fa/0x740 mm/slab.c:3718 kmalloc include/linux/slab.h:550 [inline] tty_buffer_alloc drivers/tty/tty_buffer.c:175 [inline] __tty_buffer_request_room+0x2bf/0x7e0 drivers/tty/tty_buffer.c:273 tty_insert_flip_string_fixed_flag+0x93/0x1f0 drivers/tty/tty_buffer.c:318 tty_insert_flip_string include/linux/tty_flip.h:37 [inline] pty_write+0x133/0x200 drivers/tty/pty.c:122 n_tty_write+0xb9e/0x1220 drivers/tty/n_tty.c:2354 do_tty_write drivers/tty/tty_io.c:959 [inline] tty_write+0x45b/0x7a0 drivers/tty/tty_io.c:1043 __vfs_write+0x116/0xb40 fs/read_write.c:485 vfs_write+0x20c/0x580 fs/read_write.c:549 ksys_write+0x105/0x260 fs/read_write.c:598 __do_sys_write fs/read_write.c:610 [inline] __se_sys_write fs/read_write.c:607 [inline] __x64_sys_write+0x73/0xb0 fs/read_write.c:607 do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe -> #2 (&(&port->lock)->rlock){-.-.}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x95/0xcd kernel/locking/spinlock.c:152 tty_port_tty_get+0x22/0x80 drivers/tty/tty_port.c:287 tty_port_default_wakeup+0x16/0x40 drivers/tty/tty_port.c:47 tty_port_tty_wakeup+0x5d/0x70 drivers/tty/tty_port.c:387 uart_write_wakeup+0x46/0x70 drivers/tty/serial/serial_core.c:103 serial8250_tx_chars+0x4a4/0xb20 drivers/tty/serial/8250/8250_port.c:1806 serial8250_handle_irq.part.0+0x1be/0x2e0 drivers/tty/serial/8250/8250_port.c:1879 serial8250_handle_irq drivers/tty/serial/8250/8250_port.c:1865 [inline] serial8250_default_handle_irq+0xc5/0x150 drivers/tty/serial/8250/8250_port.c:1895 serial8250_interrupt+0xfb/0x1a0 drivers/tty/serial/8250/8250_core.c:125 __handle_irq_event_percpu+0x1c6/0xb10 kernel/irq/handle.c:149 handle_irq_event_percpu+0xa0/0x1d0 kernel/irq/handle.c:189 handle_irq_event+0xa7/0x134 kernel/irq/handle.c:206 handle_edge_irq+0x232/0x8a0 kernel/irq/chip.c:791 generic_handle_irq_desc include/linux/irqdesc.h:154 [inline] handle_irq+0x252/0x3d8 arch/x86/kernel/irq_64.c:78 do_IRQ+0x99/0x1d0 arch/x86/kernel/irq.c:246 ret_from_intr+0x0/0x1e native_safe_halt+0x2/0x10 arch/x86/include/asm/irqflags.h:57 arch_cpu_idle+0x10/0x20 arch/x86/kernel/process.c:555 default_idle_call+0x36/0x90 kernel/sched/idle.c:93 cpuidle_idle_call kernel/sched/idle.c:153 [inline] do_idle+0x386/0x5d0 kernel/sched/idle.c:262 cpu_startup_entry+0x1b/0x20 kernel/sched/idle.c:353 start_secondary+0x435/0x620 arch/x86/kernel/smpboot.c:271 secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:243 -> #1 (&port_lock_key){-.-.}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x95/0xcd kernel/locking/spinlock.c:152 serial8250_console_write+0x253/0xab0 drivers/tty/serial/8250/8250_port.c:3245 univ8250_console_write+0x5f/0x70 drivers/tty/serial/8250/8250_core.c:586 call_console_drivers kernel/printk/printk.c:1737 [inline] console_unlock+0xcff/0x11e0 kernel/printk/printk.c:2408 vprintk_emit+0x370/0x960 kernel/printk/printk.c:1931 vprintk_default+0x28/0x30 kernel/printk/printk.c:1958 vprintk_func+0x7e/0x189 kernel/printk/printk_safe.c:398 printk+0xba/0xed kernel/printk/printk.c:1991 register_console+0x74d/0xb50 kernel/printk/printk.c:2723 univ8250_console_init+0x3e/0x4b drivers/tty/serial/8250/8250_core.c:681 console_init+0x6b7/0x9fe kernel/printk/printk.c:2809 start_kernel+0x5df/0x8bd init/main.c:667 x86_64_start_reservations+0x29/0x2b arch/x86/kernel/head64.c:470 x86_64_start_kernel+0x77/0x7b arch/x86/kernel/head64.c:451 secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:243 -> #0 (console_owner){-.-.}: lock_acquire+0x1db/0x570 kernel/locking/lockdep.c:3841 console_lock_spinning_enable kernel/printk/printk.c:1600 [inline] console_unlock+0x53d/0x11e0 kernel/printk/printk.c:2405 vprintk_emit+0x370/0x960 kernel/printk/printk.c:1931 vprintk_default+0x28/0x30 kernel/printk/printk.c:1958 vprintk_func+0x7e/0x189 kernel/printk/printk_safe.c:398 printk+0xba/0xed kernel/printk/printk.c:1991 __list_del_entry_valid.cold+0x23/0x4f lib/list_debug.c:45 __list_del_entry include/linux/list.h:117 [inline] list_del include/linux/list.h:125 [inline] free_block+0xd8/0x250 mm/slab.c:3403 drain_array_locked+0x36/0x90 mm/slab.c:2195 drain_array+0x8c/0xb0 mm/slab.c:4009 cache_reap+0xf4/0x280 mm/slab.c:4050 process_one_work+0xd0c/0x1ce0 kernel/workqueue.c:2153 worker_thread+0x143/0x14a0 kernel/workqueue.c:2296 kthread+0x357/0x430 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352 other info that might help us debug this: Chain exists of: console_owner --> &(&port->lock)->rlock --> &(&parent->list_lock)->rlock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&(&parent->list_lock)->rlock); lock(&(&port->lock)->rlock); lock(&(&parent->list_lock)->rlock); lock(console_owner); *** DEADLOCK *** 5 locks held by kworker/1:3/7418: #0: 0000000045216fdd ((wq_completion)"events"){+.+.}, at: __write_once_size include/linux/compiler.h:218 [inline] #0: 0000000045216fdd ((wq_completion)"events"){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: 0000000045216fdd ((wq_completion)"events"){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:40 [inline] #0: 0000000045216fdd ((wq_completion)"events"){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:59 [inline] #0: 0000000045216fdd ((wq_completion)"events"){+.+.}, at: set_work_data kernel/workqueue.c:617 [inline] #0: 0000000045216fdd ((wq_completion)"events"){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline] #0: 0000000045216fdd ((wq_completion)"events"){+.+.}, at: process_one_work+0xbc7/0x1ce0 kernel/workqueue.c:2124 #1: 0000000032218038 ((work_completion)(&(reap_work)->work)){+.+.}, at: process_one_work+0xc1d/0x1ce0 kernel/workqueue.c:2128 #2: 0000000013b9d8f5 (slab_mutex){+.+.}, at: cache_reap+0x38/0x280 mm/slab.c:4034 #3: 00000000adc514b9 (&(&parent->list_lock)->rlock){-.-.}, at: spin_lock_irq include/linux/spinlock.h:354 [inline] #3: 00000000adc514b9 (&(&parent->list_lock)->rlock){-.-.}, at: drain_array+0x7a/0xb0 mm/slab.c:4008 #4: 0000000024e94b7c (console_lock){+.+.}, at: console_trylock_spinning kernel/printk/printk.c:1662 [inline] #4: 0000000024e94b7c (console_lock){+.+.}, at: vprintk_emit+0x351/0x960 kernel/printk/printk.c:1930 stack backtrace: CPU: 1 PID: 7418 Comm: kworker/1:3 Not tainted 4.20.0+ #12 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: events cache_reap Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1db/0x2d0 lib/dump_stack.c:113 print_circular_bug.isra.0.cold+0x1cc/0x28f kernel/locking/lockdep.c:1224 check_prev_add kernel/locking/lockdep.c:1866 [inline] check_prevs_add kernel/locking/lockdep.c:1979 [inline] validate_chain kernel/locking/lockdep.c:2350 [inline] __lock_acquire+0x3014/0x4a30 kernel/locking/lockdep.c:3338 lock_acquire+0x1db/0x570 kernel/locking/lockdep.c:3841 console_lock_spinning_enable kernel/printk/printk.c:1600 [inline] console_unlock+0x53d/0x11e0 kernel/printk/printk.c:2405 vprintk_emit+0x370/0x960 kernel/printk/printk.c:1931 vprintk_default+0x28/0x30 kernel/printk/printk.c:1958 vprintk_func+0x7e/0x189 kernel/printk/printk_safe.c:398 printk+0xba/0xed kernel/printk/printk.c:1991 __list_del_entry_valid.cold+0x23/0x4f lib/list_debug.c:45 __list_del_entry include/linux/list.h:117 [inline] list_del include/linux/list.h:125 [inline] free_block+0xd8/0x250 mm/slab.c:3403 drain_array_locked+0x36/0x90 mm/slab.c:2195 drain_array+0x8c/0xb0 mm/slab.c:4009 cache_reap+0xf4/0x280 mm/slab.c:4050 process_one_work+0xd0c/0x1ce0 kernel/workqueue.c:2153 worker_thread+0x143/0x14a0 kernel/workqueue.c:2296 kthread+0x357/0x430 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352 ---[ end trace 55fa1a801a0e0d1e ]--- RIP: 0010:__list_del_entry_valid.cold+0x23/0x4f lib/list_debug.c:45 Code: e8 95 5d d7 fd 0f 0b 4c 89 f6 48 c7 c7 c0 b1 81 88 e8 84 5d d7 fd 0f 0b 4c 89 ea 4c 89 f6 48 c7 c7 00 b1 81 88 e8 70 5d d7 fd <0f> 0b 4c 89 e2 4c 89 f6 48 c7 c7 60 b1 81 88 e8 5c 5d d7 fd 0f 0b RSP: 0018:ffff8880898b7888 EFLAGS: 00010082 RAX: 000000000000004e RBX: ffffe8ffffd65bd0 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff81684ce6 RDI: ffffed1011316f03 RBP: ffff8880898b78a0 R08: 000000000000004e R09: ffffed1015ce5021 R10: ffffed1015ce5020 R11: ffff8880ae728107 R12: dead000000000200 R13: dead000000000100 R14: ffffea0000f33bc8 R15: ffffea0000f33bc8 FS: 0000000000000000(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000c42cbb8410 CR3: 0000000085594000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400