Hello, syzbot found the following issue on: HEAD commit: f6e7a024 Merge tag 'arc-5.11-rc3' of git://git.kernel.org/.. git tree: net-next console output: https://syzkaller.appspot.com/x/log.txt?x=135c95fb500000 kernel config: https://syzkaller.appspot.com/x/.config?x=8aa30b9da402d224 dashboard link: https://syzkaller.appspot.com/bug?extid=d8d5fa7f3a0c96bcdc78 compiler: gcc (GCC) 10.1.0-syz 20200507 Unfortunately, I don't have any reproducer for this issue yet. IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+d8d5fa7f3a0c96bcdc78@xxxxxxxxxxxxxxxxxxxxxxxxx ======================================================== WARNING: possible irq lock inversion dependency detected 5.11.0-rc2-syzkaller #0 Not tainted -------------------------------------------------------- kworker/1:0/19 just changed the state of lock: ffff88805f80b0a0 (wq_mayday_lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:359 [inline] ffff88805f80b0a0 (wq_mayday_lock){+.-.}-{2:2}, at: lock_sock_nested+0x3b/0x110 net/core/sock.c:3049 but this lock was taken by another, HARDIRQ-safe lock in the past: (&pool->lock){-.-.}-{2:2} and interrupts could create inverse lock ordering between them. other info that might help us debug this: Possible interrupt unsafe locking scenario: CPU0 CPU1 ---- ---- lock(wq_mayday_lock); local_irq_disable(); lock(&pool->lock); lock(wq_mayday_lock); <Interrupt> lock(&pool->lock); *** DEADLOCK *** 4 locks held by kworker/1:0/19: #0: ffff888010062d38 ((wq_completion)events){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff888010062d38 ((wq_completion)events){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline] #0: ffff888010062d38 ((wq_completion)events){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline] #0: ffff888010062d38 ((wq_completion)events){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:616 [inline] #0: ffff888010062d38 ((wq_completion)events){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:643 [inline] #0: ffff888010062d38 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x871/0x15f0 kernel/workqueue.c:2246 #1: ffffc90000d97da8 ((work_completion)(&(&chan->chan_timer)->work)){+.+.}-{0:0}, at: process_one_work+0x8a5/0x15f0 kernel/workqueue.c:2250 #2: ffff88802fc01ad8 (&conn->chan_lock){+.+.}-{3:3}, at: l2cap_chan_timeout+0x69/0x2f0 net/bluetooth/l2cap_core.c:422 #3: ffff8880623c6520 (&chan->lock/1){+.+.}-{3:3}, at: l2cap_chan_lock include/net/bluetooth/l2cap.h:852 [inline] #3: ffff8880623c6520 (&chan->lock/1){+.+.}-{3:3}, at: l2cap_chan_timeout+0xb5/0x2f0 net/bluetooth/l2cap_core.c:426 the shortest dependencies between 2nd lock and 1st lock: -> (&pool->lock){-.-.}-{2:2} { IN-HARDIRQ-W at: lock_acquire kernel/locking/lockdep.c:5437 [inline] lock_acquire+0x29d/0x740 kernel/locking/lockdep.c:5402 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:151 __queue_work+0x375/0xf00 kernel/workqueue.c:1455 queue_work_on+0xc7/0xd0 kernel/workqueue.c:1524 tick_nohz_activate kernel/time/tick-sched.c:1285 [inline] tick_nohz_activate kernel/time/tick-sched.c:1278 [inline] tick_setup_sched_timer+0x1e8/0x320 kernel/time/tick-sched.c:1419 hrtimer_switch_to_hres kernel/time/hrtimer.c:738 [inline] hrtimer_run_queues+0x339/0x400 kernel/time/hrtimer.c:1745 run_local_timers kernel/time/timer.c:1756 [inline] update_process_times+0xc0/0x200 kernel/time/timer.c:1781 tick_periodic+0x79/0x230 kernel/time/tick-common.c:100 tick_handle_periodic+0x41/0x120 kernel/time/tick-common.c:112 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1085 [inline] __sysvec_apic_timer_interrupt+0x146/0x540 arch/x86/kernel/apic/apic.c:1102 asm_call_irq_on_stack+0xf/0x20 __run_sysvec_on_irqstack arch/x86/include/asm/irq_stack.h:37 [inline] run_sysvec_on_irqstack_cond arch/x86/include/asm/irq_stack.h:89 [inline] sysvec_apic_timer_interrupt+0xbd/0x100 arch/x86/kernel/apic/apic.c:1096 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:628 native_restore_fl arch/x86/include/asm/irqflags.h:41 [inline] arch_local_irq_restore arch/x86/include/asm/irqflags.h:84 [inline] console_unlock+0x7b6/0xbb0 kernel/printk/printk.c:2560 vprintk_emit+0x189/0x490 kernel/printk/printk.c:2074 vprintk_func+0x8d/0x1e0 kernel/printk/printk_safe.c:393 printk+0xba/0xed kernel/printk/printk.c:2122 __clocksource_select.cold+0x7c/0xaf kernel/time/clocksource.c:776 clocksource_select kernel/time/clocksource.c:791 [inline] clocksource_done_booting+0x35/0x44 kernel/time/clocksource.c:815 do_one_initcall+0x103/0x650 init/main.c:1217 do_initcall_level init/main.c:1290 [inline] do_initcalls init/main.c:1306 [inline] do_basic_setup init/main.c:1326 [inline] kernel_init_freeable+0x605/0x689 init/main.c:1533 kernel_init+0xd/0x1b8 init/main.c:1415 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296 IN-SOFTIRQ-W at: lock_acquire kernel/locking/lockdep.c:5437 [inline] lock_acquire+0x29d/0x740 kernel/locking/lockdep.c:5402 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:151 __queue_work+0x375/0xf00 kernel/workqueue.c:1455 call_timer_fn+0x1a5/0x6b0 kernel/time/timer.c:1417 expire_timers kernel/time/timer.c:1457 [inline] __run_timers.part.0+0x4a6/0xa50 kernel/time/timer.c:1731 __run_timers kernel/time/timer.c:1712 [inline] run_timer_softirq+0xb3/0x1d0 kernel/time/timer.c:1744 __do_softirq+0x2a5/0x9f7 kernel/softirq.c:343 asm_call_irq_on_stack+0xf/0x20 __run_on_irqstack arch/x86/include/asm/irq_stack.h:26 [inline] run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:77 [inline] do_softirq_own_stack+0xaa/0xd0 arch/x86/kernel/irq_64.c:77 invoke_softirq kernel/softirq.c:226 [inline] __irq_exit_rcu kernel/softirq.c:420 [inline] irq_exit_rcu+0x134/0x200 kernel/softirq.c:432 sysvec_apic_timer_interrupt+0x4d/0x100 arch/x86/kernel/apic/apic.c:1096 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:628 native_safe_halt arch/x86/include/asm/irqflags.h:60 [inline] arch_safe_halt arch/x86/include/asm/irqflags.h:103 [inline] default_idle+0xe/0x10 arch/x86/kernel/process.c:688 default_idle_call+0x87/0xd0 kernel/sched/idle.c:112 cpuidle_idle_call kernel/sched/idle.c:194 [inline] do_idle+0x3fa/0x590 kernel/sched/idle.c:299 cpu_startup_entry+0x14/0x20 kernel/sched/idle.c:396 start_secondary+0x274/0x350 arch/x86/kernel/smpboot.c:271 secondary_startup_64_no_verify+0xb0/0xbb INITIAL USE at: lock_acquire kernel/locking/lockdep.c:5437 [inline] lock_acquire+0x29d/0x740 kernel/locking/lockdep.c:5402 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x39/0x50 kernel/locking/spinlock.c:159 pwq_adjust_max_active+0x177/0x5f0 kernel/workqueue.c:3726 link_pwq+0x144/0x290 kernel/workqueue.c:3792 alloc_and_link_pwqs kernel/workqueue.c:4186 [inline] alloc_workqueue+0x66f/0xe70 kernel/workqueue.c:4308 workqueue_init_early+0x508/0x69b kernel/workqueue.c:5982 start_kernel+0x1f3/0x48c init/main.c:939 secondary_startup_64_no_verify+0xb0/0xbb } ... key at: [<ffffffff8e4bf920>] __key.20+0x0/0x40 ... acquired at: __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:151 pool_mayday_timeout+0x36/0x5a0 kernel/workqueue.c:2046 call_timer_fn+0x1a5/0x6b0 kernel/time/timer.c:1417 expire_timers kernel/time/timer.c:1462 [inline] __run_timers.part.0+0x67c/0xa50 kernel/time/timer.c:1731 __run_timers kernel/time/timer.c:1712 [inline] run_timer_softirq+0xb3/0x1d0 kernel/time/timer.c:1744 __do_softirq+0x2a5/0x9f7 kernel/softirq.c:343 asm_call_irq_on_stack+0xf/0x20 __run_on_irqstack arch/x86/include/asm/irq_stack.h:26 [inline] run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:77 [inline] do_softirq_own_stack+0xaa/0xd0 arch/x86/kernel/irq_64.c:77 invoke_softirq kernel/softirq.c:226 [inline] __irq_exit_rcu kernel/softirq.c:420 [inline] irq_exit_rcu+0x134/0x200 kernel/softirq.c:432 sysvec_apic_timer_interrupt+0x4d/0x100 arch/x86/kernel/apic/apic.c:1096 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:628 native_restore_fl arch/x86/include/asm/irqflags.h:41 [inline] arch_local_irq_restore arch/x86/include/asm/irqflags.h:84 [inline] lock_acquire kernel/locking/lockdep.c:5440 [inline] lock_acquire+0x2c7/0x740 kernel/locking/lockdep.c:5402 rcu_lock_acquire include/linux/rcupdate.h:259 [inline] rcu_read_lock include/linux/rcupdate.h:648 [inline] inet_twsk_purge+0x112/0x7c0 net/ipv4/inet_timewait_sock.c:268 ops_exit_list+0x10d/0x160 net/core/net_namespace.c:190 setup_net+0x508/0x850 net/core/net_namespace.c:365 copy_net_ns+0x31e/0x760 net/core/net_namespace.c:483 create_new_namespaces+0x3f6/0xb20 kernel/nsproxy.c:110 unshare_nsproxy_namespaces+0xbd/0x1f0 kernel/nsproxy.c:226 ksys_unshare+0x445/0x8e0 kernel/fork.c:2957 __do_sys_unshare kernel/fork.c:3025 [inline] __se_sys_unshare kernel/fork.c:3023 [inline] __x64_sys_unshare+0x2d/0x40 kernel/fork.c:3023 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 -> (wq_mayday_lock){+.-.}-{2:2} { HARDIRQ-ON-W at: lock_acquire kernel/locking/lockdep.c:5437 [inline] lock_acquire+0x29d/0x740 kernel/locking/lockdep.c:5402 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:135 [inline] _raw_spin_lock_bh+0x2f/0x40 kernel/locking/spinlock.c:175 spin_lock_bh include/linux/spinlock.h:359 [inline] lock_sock_nested+0x3b/0x110 net/core/sock.c:3049 l2cap_sock_teardown_cb+0xa1/0x660 net/bluetooth/l2cap_sock.c:1520 l2cap_chan_del+0xbc/0xa80 net/bluetooth/l2cap_core.c:618 l2cap_chan_close+0x1bc/0xaf0 net/bluetooth/l2cap_core.c:823 l2cap_chan_timeout+0x17e/0x2f0 net/bluetooth/l2cap_core.c:436 process_one_work+0x98d/0x15f0 kernel/workqueue.c:2275 worker_thread+0x64c/0x1120 kernel/workqueue.c:2421 kthread+0x3b1/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296 IN-SOFTIRQ-W at: lock_acquire kernel/locking/lockdep.c:5437 [inline] lock_acquire+0x29d/0x740 kernel/locking/lockdep.c:5402 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:151 pool_mayday_timeout+0x36/0x5a0 kernel/workqueue.c:2046 call_timer_fn+0x1a5/0x6b0 kernel/time/timer.c:1417 expire_timers kernel/time/timer.c:1462 [inline] __run_timers.part.0+0x67c/0xa50 kernel/time/timer.c:1731 __run_timers kernel/time/timer.c:1712 [inline] run_timer_softirq+0xb3/0x1d0 kernel/time/timer.c:1744 __do_softirq+0x2a5/0x9f7 kernel/softirq.c:343 asm_call_irq_on_stack+0xf/0x20 __run_on_irqstack arch/x86/include/asm/irq_stack.h:26 [inline] run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:77 [inline] do_softirq_own_stack+0xaa/0xd0 arch/x86/kernel/irq_64.c:77 invoke_softirq kernel/softirq.c:226 [inline] __irq_exit_rcu kernel/softirq.c:420 [inline] irq_exit_rcu+0x134/0x200 kernel/softirq.c:432 sysvec_apic_timer_interrupt+0x4d/0x100 arch/x86/kernel/apic/apic.c:1096 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:628 loop2+0x8/0x39e INITIAL USE at: lock_acquire kernel/locking/lockdep.c:5437 [inline] lock_acquire+0x29d/0x740 kernel/locking/lockdep.c:5402 __raw_spin_lock_irq include/linux/spinlock_api_smp.h:128 [inline] _raw_spin_lock_irq+0x32/0x50 kernel/locking/spinlock.c:167 rescuer_thread+0x1cc/0xd30 kernel/workqueue.c:2495 kthread+0x3b1/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296 } ... key at: [<ffffffff8b22dff8>] wq_mayday_lock+0x18/0x60 ... acquired at: mark_usage kernel/locking/lockdep.c:4320 [inline] __lock_acquire+0x857/0x5500 kernel/locking/lockdep.c:4786 lock_acquire kernel/locking/lockdep.c:5437 [inline] lock_acquire+0x29d/0x740 kernel/locking/lockdep.c:5402 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:135 [inline] _raw_spin_lock_bh+0x2f/0x40 kernel/locking/spinlock.c:175 spin_lock_bh include/linux/spinlock.h:359 [inline] lock_sock_nested+0x3b/0x110 net/core/sock.c:3049 l2cap_sock_teardown_cb+0xa1/0x660 net/bluetooth/l2cap_sock.c:1520 l2cap_chan_del+0xbc/0xa80 net/bluetooth/l2cap_core.c:618 l2cap_chan_close+0x1bc/0xaf0 net/bluetooth/l2cap_core.c:823 l2cap_chan_timeout+0x17e/0x2f0 net/bluetooth/l2cap_core.c:436 process_one_work+0x98d/0x15f0 kernel/workqueue.c:2275 worker_thread+0x64c/0x1120 kernel/workqueue.c:2421 kthread+0x3b1/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296 stack backtrace: CPU: 1 PID: 19 Comm: kworker/1:0 Not tainted 5.11.0-rc2-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: events l2cap_chan_timeout Call Trace: __dump_stack lib/dump_stack.c:79 [inline] dump_stack+0x107/0x163 lib/dump_stack.c:120 print_irq_inversion_bug kernel/locking/lockdep.c:3740 [inline] check_usage_backwards kernel/locking/lockdep.c:3884 [inline] mark_lock_irq kernel/locking/lockdep.c:3974 [inline] mark_lock.cold+0x1a/0x73 kernel/locking/lockdep.c:4411 mark_usage kernel/locking/lockdep.c:4320 [inline] __lock_acquire+0x857/0x5500 kernel/locking/lockdep.c:4786 lock_acquire kernel/locking/lockdep.c:5437 [inline] lock_acquire+0x29d/0x740 kernel/locking/lockdep.c:5402 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:135 [inline] _raw_spin_lock_bh+0x2f/0x40 kernel/locking/spinlock.c:175 spin_lock_bh include/linux/spinlock.h:359 [inline] lock_sock_nested+0x3b/0x110 net/core/sock.c:3049 l2cap_sock_teardown_cb+0xa1/0x660 net/bluetooth/l2cap_sock.c:1520 l2cap_chan_del+0xbc/0xa80 net/bluetooth/l2cap_core.c:618 l2cap_chan_close+0x1bc/0xaf0 net/bluetooth/l2cap_core.c:823 l2cap_chan_timeout+0x17e/0x2f0 net/bluetooth/l2cap_core.c:436 process_one_work+0x98d/0x15f0 kernel/workqueue.c:2275 worker_thread+0x64c/0x1120 kernel/workqueue.c:2421 kthread+0x3b1/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296 ================================================================================ UBSAN: array-index-out-of-bounds in kernel/locking/qspinlock.c:130:9 index 8847 is out of range for type 'long unsigned int [8]' CPU: 1 PID: 19 Comm: kworker/1:0 Not tainted 5.11.0-rc2-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: events l2cap_chan_timeout Call Trace: __dump_stack lib/dump_stack.c:79 [inline] dump_stack+0x107/0x163 lib/dump_stack.c:120 ubsan_epilogue+0xb/0x5a lib/ubsan.c:148 __ubsan_handle_out_of_bounds.cold+0x62/0x6c lib/ubsan.c:356 decode_tail kernel/locking/qspinlock.c:130 [inline] __pv_queued_spin_lock_slowpath+0xa3f/0xb40 kernel/locking/qspinlock.c:468 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:554 [inline] queued_spin_lock_slowpath arch/x86/include/asm/qspinlock.h:51 [inline] queued_spin_lock include/asm-generic/qspinlock.h:85 [inline] do_raw_spin_lock+0x200/0x2b0 kernel/locking/spinlock_debug.c:113 spin_lock_bh include/linux/spinlock.h:359 [inline] lock_sock_nested+0x3b/0x110 net/core/sock.c:3049 l2cap_sock_teardown_cb+0xa1/0x660 net/bluetooth/l2cap_sock.c:1520 l2cap_chan_del+0xbc/0xa80 net/bluetooth/l2cap_core.c:618 l2cap_chan_close+0x1bc/0xaf0 net/bluetooth/l2cap_core.c:823 l2cap_chan_timeout+0x17e/0x2f0 net/bluetooth/l2cap_core.c:436 process_one_work+0x98d/0x15f0 kernel/workqueue.c:2275 worker_thread+0x64c/0x1120 kernel/workqueue.c:2421 kthread+0x3b1/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296 ================================================================================ --- This report is generated by a bot. 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