====================================================== WARNING: possible circular locking dependency detected 6.3.0-rc3-syzkaller-00005-g7d31677bb7b1 #0 Not tainted ------------------------------------------------------ kworker/3:0/31 is trying to acquire lock: ffff88802cbbba98 (&pool->lock){-.-.}-{2:2}, at: __queue_work+0x367/0x1120 kernel/workqueue.c:1481 but task is already holding lock: ffff88802469b528 (&tty->write_wait){-.-.}-{2:2}, at: __wake_up_common_lock+0xb8/0x140 kernel/sched/wait.c:137 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #4 (&tty->write_wait){-.-.}-{2:2}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x3d/0x60 kernel/locking/spinlock.c:162 __wake_up_common_lock+0xb8/0x140 kernel/sched/wait.c:137 tty_port_default_wakeup+0x2a/0x40 drivers/tty/tty_port.c:71 serial8250_tx_chars+0x53e/0xdf0 drivers/tty/serial/8250/8250_port.c:1865 __start_tx drivers/tty/serial/8250/8250_port.c:1582 [inline] serial8250_start_tx+0x6d5/0x850 drivers/tty/serial/8250/8250_port.c:1688 __uart_start.isra.0+0x16b/0x1b0 drivers/tty/serial/serial_core.c:141 uart_write+0x2ff/0x570 drivers/tty/serial/serial_core.c:601 process_output_block drivers/tty/n_tty.c:586 [inline] n_tty_write+0x4ce/0xfd0 drivers/tty/n_tty.c:2350 do_tty_write drivers/tty/tty_io.c:1018 [inline] file_tty_write.constprop.0+0x453/0x9c0 drivers/tty/tty_io.c:1089 redirected_tty_write+0xa5/0xc0 drivers/tty/tty_io.c:1110 call_write_iter include/linux/fs.h:1851 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x9ed/0xe10 fs/read_write.c:584 ksys_write+0x12b/0x250 fs/read_write.c:637 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd -> #3 (&port_lock_key){-.-.}-{2:2}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x3d/0x60 kernel/locking/spinlock.c:162 serial8250_console_write+0x4ba/0x1010 drivers/tty/serial/8250/8250_port.c:3401 console_emit_next_record kernel/printk/printk.c:2886 [inline] console_flush_all+0x49c/0xcc0 kernel/printk/printk.c:2942 console_unlock+0xb8/0x1f0 kernel/printk/printk.c:3016 vprintk_emit+0x1bd/0x600 kernel/printk/printk.c:2316 vprintk+0x84/0xa0 kernel/printk/printk_safe.c:50 _printk+0xbf/0xf0 kernel/printk/printk.c:2337 register_console+0x7ef/0x10e0 kernel/printk/printk.c:3467 univ8250_console_init+0x38/0x50 drivers/tty/serial/8250/8250_core.c:688 console_init+0xba/0x5c0 kernel/printk/printk.c:3610 start_kernel+0x273/0x4d0 init/main.c:1077 secondary_startup_64_no_verify+0xce/0xdb -> #2 (console_owner){....}-{0:0}: console_lock_spinning_enable kernel/printk/printk.c:1867 [inline] console_emit_next_record kernel/printk/printk.c:2880 [inline] console_flush_all+0x472/0xcc0 kernel/printk/printk.c:2942 console_unlock+0xb8/0x1f0 kernel/printk/printk.c:3016 vprintk_emit+0x1bd/0x600 kernel/printk/printk.c:2316 vprintk+0x84/0xa0 kernel/printk/printk_safe.c:50 _printk+0xbf/0xf0 kernel/printk/printk.c:2337 build_zonelists+0x357/0x560 mm/page_alloc.c:6542 __build_all_zonelists+0x122/0x180 mm/page_alloc.c:6655 build_all_zonelists_init+0x1c/0x190 mm/page_alloc.c:6680 build_all_zonelists+0x4a/0x150 mm/page_alloc.c:6713 start_kernel+0xb7/0x4d0 init/main.c:971 secondary_startup_64_no_verify+0xce/0xdb -> #1 (zonelist_update_seq.seqcount){...-}-{0:0}: seqcount_lockdep_reader_access include/linux/seqlock.h:102 [inline] read_seqbegin include/linux/seqlock.h:836 [inline] zonelist_iter_begin mm/page_alloc.c:4764 [inline] __alloc_pages_slowpath.constprop.0+0x15a/0x2170 mm/page_alloc.c:5085 __alloc_pages+0x408/0x4a0 mm/page_alloc.c:5604 __alloc_pages_node include/linux/gfp.h:237 [inline] kmem_getpages mm/slab.c:1360 [inline] cache_grow_begin+0x9b/0x3b0 mm/slab.c:2570 cache_alloc_refill+0x27f/0x380 mm/slab.c:2943 ____cache_alloc mm/slab.c:3019 [inline] ____cache_alloc mm/slab.c:3002 [inline] __do_cache_alloc mm/slab.c:3202 [inline] slab_alloc_node mm/slab.c:3250 [inline] slab_alloc mm/slab.c:3266 [inline] __kmem_cache_alloc_lru mm/slab.c:3443 [inline] kmem_cache_alloc+0x397/0x3f0 mm/slab.c:3452 kmem_cache_zalloc include/linux/slab.h:710 [inline] fill_pool+0x264/0x5c0 lib/debugobjects.c:168 __debug_object_init+0x77/0xf10 lib/debugobjects.c:569 debug_object_init lib/debugobjects.c:624 [inline] debug_object_activate+0x330/0x3e0 lib/debugobjects.c:710 debug_work_activate kernel/workqueue.c:513 [inline] __queue_work+0x614/0x1120 kernel/workqueue.c:1523 queue_work_on+0xf2/0x110 kernel/workqueue.c:1552 queue_work include/linux/workqueue.h:504 [inline] schedule_work include/linux/workqueue.h:565 [inline] wireless_send_event+0x6d9/0xc70 net/wireless/wext-core.c:635 __cfg80211_ibss_joined+0x3d2/0x4a0 net/wireless/ibss.c:55 cfg80211_process_wdev_events+0x41a/0x630 net/wireless/util.c:1053 cfg80211_process_rdev_events+0x9f/0x130 net/wireless/util.c:1081 cfg80211_event_work+0x2b/0x40 net/wireless/core.c:328 process_one_work+0x991/0x15c0 kernel/workqueue.c:2390 worker_thread+0x669/0x1090 kernel/workqueue.c:2537 kthread+0x2e8/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 -> #0 (&pool->lock){-.-.}-{2:2}: check_prev_add kernel/locking/lockdep.c:3098 [inline] check_prevs_add kernel/locking/lockdep.c:3217 [inline] validate_chain kernel/locking/lockdep.c:3832 [inline] __lock_acquire+0x2ec7/0x5d40 kernel/locking/lockdep.c:5056 lock_acquire kernel/locking/lockdep.c:5669 [inline] lock_acquire+0x1af/0x520 kernel/locking/lockdep.c:5634 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154 __queue_work+0x367/0x1120 kernel/workqueue.c:1481 queue_work_on+0xf2/0x110 kernel/workqueue.c:1552 queue_work include/linux/workqueue.h:504 [inline] schedule_work include/linux/workqueue.h:565 [inline] p9_pollwake+0xc1/0x1d0 net/9p/trans_fd.c:539 __wake_up_common+0x147/0x650 kernel/sched/wait.c:107 __wake_up_common_lock+0xd4/0x140 kernel/sched/wait.c:138 tty_write_unlock drivers/tty/tty_io.c:939 [inline] do_tty_write drivers/tty/tty_io.c:1043 [inline] file_tty_write.constprop.0+0x505/0x9c0 drivers/tty/tty_io.c:1089 __kernel_write_iter+0x262/0x7a0 fs/read_write.c:517 __kernel_write fs/read_write.c:537 [inline] kernel_write fs/read_write.c:558 [inline] kernel_write+0x1c1/0x670 fs/read_write.c:548 p9_fd_write net/9p/trans_fd.c:433 [inline] p9_write_work+0x25a/0xc60 net/9p/trans_fd.c:484 process_one_work+0x991/0x15c0 kernel/workqueue.c:2390 worker_thread+0x669/0x1090 kernel/workqueue.c:2537 kthread+0x2e8/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 other info that might help us debug this: Chain exists of: &pool->lock --> &port_lock_key --> &tty->write_wait Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&tty->write_wait); lock(&port_lock_key); lock(&tty->write_wait); lock(&pool->lock); *** DEADLOCK *** 5 locks held by kworker/3:0/31: #0: ffff888012469d38 ((wq_completion)events){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff888012469d38 ((wq_completion)events){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline] #0: ffff888012469d38 ((wq_completion)events){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1280 [inline] #0: ffff888012469d38 ((wq_completion)events){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:639 [inline] #0: ffff888012469d38 ((wq_completion)events){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:666 [inline] #0: ffff888012469d38 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x87a/0x15c0 kernel/workqueue.c:2361 #1: ffffc9000065fda8 ((work_completion)(&m->wq)){+.+.}-{0:0}, at: process_one_work+0x8ae/0x15c0 kernel/workqueue.c:2365 #2: ffff88802469b098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x26/0x80 drivers/tty/tty_ldisc.c:244 #3: ffff88802469b528 (&tty->write_wait){-.-.}-{2:2}, at: __wake_up_common_lock+0xb8/0x140 kernel/sched/wait.c:137 #4: ffffffff8c792700 (rcu_read_lock){....}-{1:2}, at: __queue_work+0xca/0x1120 kernel/workqueue.c:1444 stack backtrace: CPU: 3 PID: 31 Comm: kworker/3:0 Not tainted 6.3.0-rc3-syzkaller-00005-g7d31677bb7b1 #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.14.0-2 04/01/2014 Workqueue: events p9_write_work Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd9/0x150 lib/dump_stack.c:106 check_noncircular+0x25f/0x2e0 kernel/locking/lockdep.c:2178 check_prev_add kernel/locking/lockdep.c:3098 [inline] check_prevs_add kernel/locking/lockdep.c:3217 [inline] validate_chain kernel/locking/lockdep.c:3832 [inline] __lock_acquire+0x2ec7/0x5d40 kernel/locking/lockdep.c:5056 lock_acquire kernel/locking/lockdep.c:5669 [inline] lock_acquire+0x1af/0x520 kernel/locking/lockdep.c:5634 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154 __queue_work+0x367/0x1120 kernel/workqueue.c:1481 queue_work_on+0xf2/0x110 kernel/workqueue.c:1552 queue_work include/linux/workqueue.h:504 [inline] schedule_work include/linux/workqueue.h:565 [inline] p9_pollwake+0xc1/0x1d0 net/9p/trans_fd.c:539 __wake_up_common+0x147/0x650 kernel/sched/wait.c:107 __wake_up_common_lock+0xd4/0x140 kernel/sched/wait.c:138 tty_write_unlock drivers/tty/tty_io.c:939 [inline] do_tty_write drivers/tty/tty_io.c:1043 [inline] file_tty_write.constprop.0+0x505/0x9c0 drivers/tty/tty_io.c:1089 __kernel_write_iter+0x262/0x7a0 fs/read_write.c:517 __kernel_write fs/read_write.c:537 [inline] kernel_write fs/read_write.c:558 [inline] kernel_write+0x1c1/0x670 fs/read_write.c:548 p9_fd_write net/9p/trans_fd.c:433 [inline] p9_write_work+0x25a/0xc60 net/9p/trans_fd.c:484 process_one_work+0x991/0x15c0 kernel/workqueue.c:2390 worker_thread+0x669/0x1090 kernel/workqueue.c:2537 kthread+0x2e8/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308