netlink: 60 bytes leftover after parsing attributes in process `syz-executor.5'. netlink: 60 bytes leftover after parsing attributes in process `syz-executor.5'. netlink: 60 bytes leftover after parsing attributes in process `syz-executor.5'. BUG: workqueue lockup - pool cpus=1 node=0 flags=0x0 nice=0 stuck for 240s! Showing busy workqueues and worker pools: workqueue events: flags=0x0 pwq 2: cpus=1 node=0 flags=0x0 nice=0 active=3/256 refcnt=4 in-flight: 28203:bpf_prog_free_deferred pending: nfc_urelease_event_work, cache_reap ====================================================== WARNING: possible circular locking dependency detected 4.19.121-syzkaller #0 Not tainted ------------------------------------------------------ systemd-udevd/8912 is trying to acquire lock: 000000004b23fac1 (console_owner){-.-.}, at: log_next kernel/printk/printk.c:499 [inline] 000000004b23fac1 (console_owner){-.-.}, at: console_unlock+0x3f4/0xfe0 kernel/printk/printk.c:2416 but task is already holding lock: 000000004c312796 (&(&pool->lock)->rlock){-.-.}, at: show_workqueue_state.cold+0x7f9/0x1059 kernel/workqueue.c:4584 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #4 (&(&pool->lock)->rlock){-.-.}: spin_lock include/linux/spinlock.h:329 [inline] __queue_work+0x1f1/0x1100 kernel/workqueue.c:1419 queue_work_on+0x17e/0x1f0 kernel/workqueue.c:1488 queue_work include/linux/workqueue.h:512 [inline] schedule_work include/linux/workqueue.h:570 [inline] put_pwq kernel/workqueue.c:1090 [inline] put_pwq+0x15a/0x1b0 kernel/workqueue.c:1075 put_pwq_unlocked.part.0+0x30/0x70 kernel/workqueue.c:1107 put_pwq_unlocked kernel/workqueue.c:1101 [inline] destroy_workqueue+0x5f4/0x6f0 kernel/workqueue.c:4243 do_floppy_init drivers/block/floppy.c:4737 [inline] floppy_async_init+0x1f0a/0x2043 drivers/block/floppy.c:4754 async_run_entry_fn+0x121/0x530 kernel/async.c:127 process_one_work+0x91f/0x1640 kernel/workqueue.c:2155 worker_thread+0x96/0xe20 kernel/workqueue.c:2298 kthread+0x34a/0x420 kernel/kthread.c:246 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 -> #3 (&pool->lock/1){..-.}: spin_lock include/linux/spinlock.h:329 [inline] __queue_work+0x1f1/0x1100 kernel/workqueue.c:1419 queue_work_on+0x17e/0x1f0 kernel/workqueue.c:1488 pty_write+0x198/0x1f0 drivers/tty/pty.c:125 tnc_init drivers/net/hamradio/6pack.c:536 [inline] sixpack_open+0x9a6/0xbc2 drivers/net/hamradio/6pack.c:632 tty_ldisc_open.isra.0+0x81/0xc0 drivers/tty/tty_ldisc.c:469 tty_set_ldisc+0x2bf/0x640 drivers/tty/tty_ldisc.c:594 tiocsetd drivers/tty/tty_io.c:2359 [inline] tty_ioctl+0x616/0x1420 drivers/tty/tty_io.c:2603 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:501 [inline] do_vfs_ioctl+0xcda/0x12e0 fs/ioctl.c:688 ksys_ioctl+0x9b/0xc0 fs/ioctl.c:705 __do_sys_ioctl fs/ioctl.c:712 [inline] __se_sys_ioctl fs/ioctl.c:710 [inline] __x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:710 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe -> #2 (&(&port->lock)->rlock){-.-.}: tty_port_tty_get+0x1d/0x80 drivers/tty/tty_port.c:289 tty_port_default_wakeup+0x11/0x40 drivers/tty/tty_port.c:47 serial8250_tx_chars+0x48f/0xae0 drivers/tty/serial/8250/8250_port.c:1806 serial8250_handle_irq.part.0+0x24b/0x290 drivers/tty/serial/8250/8250_port.c:1879 serial8250_handle_irq drivers/tty/serial/8250/8250_port.c:1865 [inline] serial8250_default_handle_irq+0xb5/0x140 drivers/tty/serial/8250/8250_port.c:1895 serial8250_interrupt+0xf2/0x1d0 drivers/tty/serial/8250/8250_core.c:125 __handle_irq_event_percpu+0x144/0x8e0 kernel/irq/handle.c:149 handle_irq_event_percpu+0x76/0x160 kernel/irq/handle.c:189 handle_irq_event+0xa2/0x12d kernel/irq/handle.c:206 handle_edge_irq+0x24b/0x8c0 kernel/irq/chip.c:797 generic_handle_irq_desc include/linux/irqdesc.h:155 [inline] handle_irq+0x35/0x50 arch/x86/kernel/irq_64.c:87 do_IRQ+0x93/0x1c0 arch/x86/kernel/irq.c:246 ret_from_intr+0x0/0x1e arch_local_irq_restore arch/x86/include/asm/paravirt.h:789 [inline] __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:160 [inline] _raw_spin_unlock_irqrestore+0x91/0xe0 kernel/locking/spinlock.c:184 spin_unlock_irqrestore include/linux/spinlock.h:384 [inline] uart_write+0x365/0x680 drivers/tty/serial/serial_core.c:612 do_output_char+0x5dd/0x850 drivers/tty/n_tty.c:445 process_output drivers/tty/n_tty.c:512 [inline] n_tty_write+0x497/0x1080 drivers/tty/n_tty.c:2343 do_tty_write drivers/tty/tty_io.c:960 [inline] tty_write+0x452/0x790 drivers/tty/tty_io.c:1044 redirected_tty_write+0xaa/0xb0 drivers/tty/tty_io.c:1065 do_loop_readv_writev fs/read_write.c:704 [inline] do_loop_readv_writev fs/read_write.c:688 [inline] do_iter_write fs/read_write.c:962 [inline] do_iter_write+0x460/0x5e0 fs/read_write.c:941 vfs_writev+0x1b3/0x2f0 fs/read_write.c:1005 do_writev+0x136/0x330 fs/read_write.c:1040 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe -> #1 (&port_lock_key){-.-.}: serial8250_console_write+0x79f/0x9c0 drivers/tty/serial/8250/8250_port.c:3251 call_console_drivers kernel/printk/printk.c:1736 [inline] console_unlock+0xb26/0xfe0 kernel/printk/printk.c:2429 vprintk_emit+0x282/0x6e0 kernel/printk/printk.c:1937 vprintk_func+0x79/0x17e kernel/printk/printk_safe.c:398 printk+0xba/0xed kernel/printk/printk.c:2012 register_console+0x752/0xb50 kernel/printk/printk.c:2745 univ8250_console_init+0x3a/0x46 drivers/tty/serial/8250/8250_core.c:684 console_init+0x4cb/0x718 kernel/printk/printk.c:2831 start_kernel+0x594/0x81c init/main.c:660 secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:243 -> #0 (console_owner){-.-.}: console_lock_spinning_enable kernel/printk/printk.c:1599 [inline] console_unlock+0x45c/0xfe0 kernel/printk/printk.c:2426 vprintk_emit+0x282/0x6e0 kernel/printk/printk.c:1937 vprintk_func+0x79/0x17e kernel/printk/printk_safe.c:398 printk+0xba/0xed kernel/printk/printk.c:2012 show_pwq kernel/workqueue.c:4490 [inline] show_workqueue_state.cold+0x94a/0x1059 kernel/workqueue.c:4586 wq_watchdog_timer_fn+0x4d8/0x550 kernel/workqueue.c:5598 call_timer_fn+0x177/0x700 kernel/time/timer.c:1326 expire_timers kernel/time/timer.c:1363 [inline] __run_timers kernel/time/timer.c:1684 [inline] __run_timers kernel/time/timer.c:1652 [inline] run_timer_softirq+0xc08/0x1540 kernel/time/timer.c:1699 __do_softirq+0x26c/0x93c kernel/softirq.c:292 invoke_softirq kernel/softirq.c:372 [inline] irq_exit+0x17b/0x1c0 kernel/softirq.c:412 exiting_irq arch/x86/include/asm/apic.h:544 [inline] smp_apic_timer_interrupt+0x136/0x550 arch/x86/kernel/apic/apic.c:1094 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:893 syscall_trace_enter+0x3d0/0xd50 arch/x86/entry/common.c:69 do_syscall_64+0x486/0x620 arch/x86/entry/common.c:283 entry_SYSCALL_64_after_hwframe+0x49/0xbe other info that might help us debug this: Chain exists of: console_owner --> &pool->lock/1 --> &(&pool->lock)->rlock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&(&pool->lock)->rlock); lock(&pool->lock/1); lock(&(&pool->lock)->rlock); lock(console_owner); *** DEADLOCK *** 4 locks held by systemd-udevd/8912: #0: 00000000c6c58ef3 ((&wq_watchdog_timer)){+.-.}, at: lockdep_copy_map include/linux/lockdep.h:168 [inline] #0: 00000000c6c58ef3 ((&wq_watchdog_timer)){+.-.}, at: call_timer_fn+0xc9/0x700 kernel/time/timer.c:1316 #1: 00000000116edce1 (rcu_read_lock_sched){....}, at: show_workqueue_state+0x0/0x120 kernel/workqueue.c:4455 #2: 000000004c312796 (&(&pool->lock)->rlock){-.-.}, at: show_workqueue_state.cold+0x7f9/0x1059 kernel/workqueue.c:4584 #3: 000000007f3d1105 (console_lock){+.+.}, at: console_trylock_spinning kernel/printk/printk.c:1661 [inline] #3: 000000007f3d1105 (console_lock){+.+.}, at: vprintk_emit+0x269/0x6e0 kernel/printk/printk.c:1936 stack backtrace: CPU: 0 PID: 8912 Comm: systemd-udevd Not tainted 4.19.121-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x188/0x20d lib/dump_stack.c:118 print_circular_bug.isra.0.cold+0x1c4/0x282 kernel/locking/lockdep.c:1221 check_prev_add kernel/locking/lockdep.c:1865 [inline] check_prevs_add kernel/locking/lockdep.c:1978 [inline] validate_chain kernel/locking/lockdep.c:2419 [inline] __lock_acquire+0x2e19/0x49c0 kernel/locking/lockdep.c:3415 lock_acquire+0x170/0x400 kernel/locking/lockdep.c:3907 console_lock_spinning_enable kernel/printk/printk.c:1599 [inline] console_unlock+0x45c/0xfe0 kernel/printk/printk.c:2426 vprintk_emit+0x282/0x6e0 kernel/printk/printk.c:1937 vprintk_func+0x79/0x17e kernel/printk/printk_safe.c:398 printk+0xba/0xed kernel/printk/printk.c:2012 show_pwq kernel/workqueue.c:4490 [inline] show_workqueue_state.cold+0x94a/0x1059 kernel/workqueue.c:4586 wq_watchdog_timer_fn+0x4d8/0x550 kernel/workqueue.c:5598 call_timer_fn+0x177/0x700 kernel/time/timer.c:1326 expire_timers kernel/time/timer.c:1363 [inline] __run_timers kernel/time/timer.c:1684 [inline] __run_timers kernel/time/timer.c:1652 [inline] run_timer_softirq+0xc08/0x1540 kernel/time/timer.c:1699 __do_softirq+0x26c/0x93c kernel/softirq.c:292 invoke_softirq kernel/softirq.c:372 [inline] irq_exit+0x17b/0x1c0 kernel/softirq.c:412 exiting_irq arch/x86/include/asm/apic.h:544 [inline] smp_apic_timer_interrupt+0x136/0x550 arch/x86/kernel/apic/apic.c:1094 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:893 RIP: 0010:syscall_trace_enter+0x3d0/0xd50 arch/x86/entry/common.c:69 Code: 3c 02 00 0f 85 6f 08 00 00 4c 8b 63 78 e8 f8 5b 67 00 48 b8 00 00 00 00 00 fc ff df 49 01 c5 4c 89 e0 41 c7 45 00 00 00 00 00 <41> c7 45 0c 00 00 00 00 48 8b 8c 24 b8 00 00 00 65 48 33 0c 25 28 RSP: 0018:ffff888218d77e30 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff13 RAX: 0000000000000003 RBX: ffff888218d77f58 RCX: ffffffff81006d75 RDX: 0000000000000000 RSI: ffffffff81006da8 RDI: 0000000000000007 RBP: ffff88804acf01c0 R08: ffff88804acf01c0 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000003 R13: ffffed10431aefca R14: 0000000000000003 R15: 000055eb5f2d8090 do_syscall_64+0x486/0x620 arch/x86/entry/common.c:283 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7feb93047a4b Code: 48 8b 34 24 eb c5 66 0f 1f 84 00 00 00 00 00 48 c7 c0 ff ff ff ff eb c8 0f 1f 80 00 00 00 00 48 63 7f 70 b8 03 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 05 f3 c3 0f 1f 00 48 8b 15 19 74 32 00 f7 d8 RSP: 002b:00007fff9c1eca28 EFLAGS: 00000206 ORIG_RAX: 0000000000000003 RAX: ffffffffffffffda RBX: 000055eb5f2d7ac0 RCX: 00007feb93047a4b RDX: 00007feb9336b900 RSI: 000055eb5f2d8090 RDI: 000000000000000f RBP: 00007feb9336c440 R08: 00007feb9423e8c0 R09: 000055eb5f2d7a00 R10: 00007feb9423e8c0 R11: 0000000000000206 R12: 0000000000000000 R13: 0000000000000001 R14: 0000000000000000 R15: 0000000000000000 workqueue events_long: flags=0x0 pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=1/256 refcnt=2 pending: br_fdb_cleanup workqueue events_unbound: flags=0x2 pwq 4: cpus=0-1 flags=0x4 nice=0 active=1/512 refcnt=4 pending: fsnotify_connector_destroy_workfn workqueue dm_bufio_cache: flags=0x8 pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=1/256 refcnt=2 pending: work_fn workqueue bat_events: flags=0xe000a pwq 4: cpus=0-1 flags=0x4 nice=0 active=1/1 refcnt=14 in-flight: 95:batadv_nc_worker delayed: batadv_nc_worker, batadv_iv_send_outstanding_bat_ogm_packet, batadv_iv_send_outstanding_bat_ogm_packet, batadv_purge_orig, batadv_purge_orig, batadv_purge_orig, batadv_iv_send_outstanding_bat_ogm_packet, batadv_nc_worker, batadv_nc_worker, batadv_nc_worker pool 2: cpus=1 node=0 flags=0x0 nice=0 hung=241s workers=4 idle: 2916 29216 7246 pool 4: cpus=0-1 flags=0x4 nice=0 hung=1s workers=5 idle: 23 479 370 7 netlink: 60 bytes leftover after parsing attributes in process `syz-executor.5'. kvm_hv_get_msr: 1 callbacks suppressed kvm [12772]: vcpu0, guest rIP: 0x135 Hyper-V unhandled rdmsr: 0x40000007 kvm [12772]: vcpu0, guest rIP: 0x145 Hyper-V unhandled rdmsr: 0x40000007 netlink: 60 bytes leftover after parsing attributes in process `syz-executor.5'. netlink: 60 bytes leftover after parsing attributes in process `syz-executor.5'. netlink: 60 bytes leftover after parsing attributes in process `syz-executor.5'. netlink: 60 bytes leftover after parsing attributes in process `syz-executor.5'. netlink: 60 bytes leftover after parsing attributes in process `syz-executor.5'. netlink: 60 bytes leftover after parsing attributes in process `syz-executor.5'.