INFO: task kworker/u4:2:56 blocked for more than 143 seconds. Not tainted 5.7.0-rc2-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/u4:2 D24544 56 2 0x80004000 Workqueue: events_unbound fsnotify_mark_destroy_workfn Call Trace: context_switch kernel/sched/core.c:3372 [inline] __schedule+0x805/0xc90 kernel/sched/core.c:4088 schedule+0x188/0x220 kernel/sched/core.c:4163 schedule_timeout+0x43/0x250 kernel/time/timer.c:1874 mark_held_locks kernel/locking/lockdep.c:3628 [inline] __trace_hardirqs_on_caller kernel/locking/lockdep.c:3657 [inline] lockdep_hardirqs_on+0x4a4/0x8a0 kernel/locking/lockdep.c:3702 __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:168 [inline] _raw_spin_unlock_irq+0x1f/0x80 kernel/locking/spinlock.c:199 do_wait_for_common+0x232/0x370 kernel/sched/completion.c:85 console_conditional_schedule+0x30/0x30 __wait_for_common kernel/sched/completion.c:106 [inline] wait_for_common kernel/sched/completion.c:117 [inline] wait_for_completion+0x43/0x50 kernel/sched/completion.c:138 __synchronize_srcu+0x1ba/0x240 kernel/rcu/srcutree.c:922 rcu_read_lock_any_held+0x1a0/0x1a0 arch/x86/include/asm/paravirt.h:754 fsnotify_mark_destroy_workfn+0xe7/0x2a0 fs/notify/mark.c:832 process_one_work+0x76e/0xfd0 kernel/workqueue.c:2268 worker_thread+0xa7f/0x1450 kernel/workqueue.c:2414 kthread+0x353/0x380 kernel/kthread.c:268 rcu_lock_release+0x20/0x20 include/linux/rcupdate.h:213 kthread_blkcg+0xd0/0xd0 kernel/kthread.c:1247 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 INFO: task kworker/u4:5:245 blocked for more than 143 seconds. Not tainted 5.7.0-rc2-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/u4:5 D25360 245 2 0x80004000 Workqueue: events_unbound fsnotify_connector_destroy_workfn Call Trace: context_switch kernel/sched/core.c:3372 [inline] __schedule+0x805/0xc90 kernel/sched/core.c:4088 schedule+0x188/0x220 kernel/sched/core.c:4163 schedule_timeout+0x43/0x250 kernel/time/timer.c:1874 mark_held_locks kernel/locking/lockdep.c:3628 [inline] __trace_hardirqs_on_caller kernel/locking/lockdep.c:3657 [inline] lockdep_hardirqs_on+0x4a4/0x8a0 kernel/locking/lockdep.c:3702 __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:168 [inline] _raw_spin_unlock_irq+0x1f/0x80 kernel/locking/spinlock.c:199 do_wait_for_common+0x232/0x370 kernel/sched/completion.c:85 console_conditional_schedule+0x30/0x30 __wait_for_common kernel/sched/completion.c:106 [inline] wait_for_common kernel/sched/completion.c:117 [inline] wait_for_completion+0x43/0x50 kernel/sched/completion.c:138 __synchronize_srcu+0x1ba/0x240 kernel/rcu/srcutree.c:922 rcu_read_lock_any_held+0x1a0/0x1a0 arch/x86/include/asm/paravirt.h:754 fsnotify_connector_destroy_workfn+0x40/0xa0 fs/notify/mark.c:164 process_one_work+0x76e/0xfd0 kernel/workqueue.c:2268 worker_thread+0xa7f/0x1450 kernel/workqueue.c:2414 kthread+0x353/0x380 kernel/kthread.c:268 rcu_lock_release+0x20/0x20 include/linux/rcupdate.h:213 kthread_blkcg+0xd0/0xd0 kernel/kthread.c:1247 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 INFO: task syz-executor.4:28849 blocked for more than 143 seconds. Not tainted 5.7.0-rc2-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.4 D28224 28849 7550 0x00004004 Call Trace: context_switch kernel/sched/core.c:3372 [inline] __schedule+0x805/0xc90 kernel/sched/core.c:4088 schedule+0x188/0x220 kernel/sched/core.c:4163 schedule_timeout+0x43/0x250 kernel/time/timer.c:1874 pv_queued_spin_unlock arch/x86/include/asm/paravirt.h:650 [inline] queued_spin_unlock arch/x86/include/asm/qspinlock.h:55 [inline] do_raw_spin_unlock+0x134/0x8d0 kernel/locking/spinlock_debug.c:139 __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:168 [inline] _raw_spin_unlock_irq+0x1f/0x80 kernel/locking/spinlock.c:199 do_wait_for_common+0x232/0x370 kernel/sched/completion.c:85 console_conditional_schedule+0x30/0x30 __wait_for_common kernel/sched/completion.c:106 [inline] wait_for_common kernel/sched/completion.c:117 [inline] wait_for_completion+0x43/0x50 kernel/sched/completion.c:138 __flush_work+0xca/0x120 kernel/workqueue.c:3045 start_flush_work+0x730/0x730 kernel/workqueue.c:3017 p9_mux_poll_stop net/9p/trans_fd.c:175 [inline] p9_conn_destroy net/9p/trans_fd.c:862 [inline] p9_fd_close+0x222/0x3a0 net/9p/trans_fd.c:898 p9_client_create+0x97c/0xef0 net/9p/client.c:1069 lockdep_init_map_wait include/linux/lockdep.h:330 [inline] __raw_spin_lock_init+0x3f/0xf0 kernel/locking/spinlock_debug.c:24 v9fs_session_init+0x192/0x18f0 fs/9p/v9fs.c:406 check_preemption_disabled+0x40/0x240 lib/smp_processor_id.c:16 lock_is_held include/linux/lockdep.h:406 [inline] rcu_read_lock_sched_held+0x106/0x170 kernel/rcu/update.c:121 trace_kmalloc+0xcb/0x120 include/trace/events/kmem.h:46 kmalloc include/linux/slab.h:555 [inline] kzalloc include/linux/slab.h:669 [inline] v9fs_mount+0x5c/0x810 fs/9p/vfs_super.c:120 kmem_cache_alloc_trace+0x24c/0x300 mm/slab.c:3552 v9fs_mount+0x7f/0x810 fs/9p/vfs_super.c:124 cap_capable+0x23f/0x280 security/commoncap.c:77 legacy_get_tree+0xea/0x180 fs/fs_context.c:622 xfs_fs_commit_blocks+0x630/0x630 vfs_get_tree+0x88/0x270 fs/super.c:1547 do_new_mount fs/namespace.c:2816 [inline] do_mount+0x17ec/0x2900 fs/namespace.c:3141 _copy_from_user+0x116/0x170 lib/usercopy.c:16 __do_sys_mount fs/namespace.c:3350 [inline] __se_sys_mount+0xd3/0x100 fs/namespace.c:3327 do_syscall_64+0xf3/0x1b0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 INFO: task syz-executor.1:28845 blocked for more than 144 seconds. Not tainted 5.7.0-rc2-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.1 D28528 28845 7171 0x00004004 Call Trace: context_switch kernel/sched/core.c:3372 [inline] __schedule+0x805/0xc90 kernel/sched/core.c:4088 schedule+0x188/0x220 kernel/sched/core.c:4163 schedule_timeout+0x43/0x250 kernel/time/timer.c:1874 pv_queued_spin_unlock arch/x86/include/asm/paravirt.h:650 [inline] queued_spin_unlock arch/x86/include/asm/qspinlock.h:55 [inline] do_raw_spin_unlock+0x134/0x8d0 kernel/locking/spinlock_debug.c:139 __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:168 [inline] _raw_spin_unlock_irq+0x1f/0x80 kernel/locking/spinlock.c:199 do_wait_for_common+0x232/0x370 kernel/sched/completion.c:85 console_conditional_schedule+0x30/0x30 __wait_for_common kernel/sched/completion.c:106 [inline] wait_for_common kernel/sched/completion.c:117 [inline] wait_for_completion+0x43/0x50 kernel/sched/completion.c:138 __synchronize_srcu+0x1ba/0x240 kernel/rcu/srcutree.c:922 rcu_read_lock_any_held+0x1a0/0x1a0 arch/x86/include/asm/paravirt.h:754 mmu_notifier_unregister+0x287/0x370 mm/mmu_notifier.c:838 kvm_destroy_vm arch/x86/kvm/../../../virt/kvm/kvm_main.c:803 [inline] kvm_put_kvm+0x670/0xcb0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:828 kvm_vcpu_mmap+0x40/0x40 arch/x86/kvm/../../../virt/kvm/kvm_main.c:2942 kvm_vcpu_release+0x79/0x80 arch/x86/kvm/../../../virt/kvm/kvm_main.c:2950 __fput+0x2ed/0x750 fs/file_table.c:280 task_work_run+0x147/0x1d0 kernel/task_work.c:123 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_usermode_loop arch/x86/entry/common.c:165 [inline] prepare_exit_to_usermode+0x48e/0x600 arch/x86/entry/common.c:196 syscall_return_slowpath+0xf9/0x420 arch/x86/entry/common.c:278 entry_SYSCALL_64_after_hwframe+0x49/0xb3 INFO: task syz-executor.5:28873 blocked for more than 144 seconds. Not tainted 5.7.0-rc2-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.5 D26192 28873 7668 0x00004004 Call Trace: context_switch kernel/sched/core.c:3372 [inline] __schedule+0x805/0xc90 kernel/sched/core.c:4088 schedule+0x188/0x220 kernel/sched/core.c:4163 schedule_timeout+0x43/0x250 kernel/time/timer.c:1874 mark_held_locks kernel/locking/lockdep.c:3628 [inline] __trace_hardirqs_on_caller kernel/locking/lockdep.c:3657 [inline] lockdep_hardirqs_on+0x4a4/0x8a0 kernel/locking/lockdep.c:3702 __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:168 [inline] _raw_spin_unlock_irq+0x1f/0x80 kernel/locking/spinlock.c:199 do_wait_for_common+0x232/0x370 kernel/sched/completion.c:85 console_conditional_schedule+0x30/0x30 __wait_for_common kernel/sched/completion.c:106 [inline] wait_for_common kernel/sched/completion.c:117 [inline] wait_for_completion+0x43/0x50 kernel/sched/completion.c:138 __flush_work+0xca/0x120 kernel/workqueue.c:3045 start_flush_work+0x730/0x730 kernel/workqueue.c:3017 drain_all_pages+0x59d/0x630 mm/page_alloc.c:2995 __alloc_pages_direct_reclaim mm/page_alloc.c:4217 [inline] __alloc_pages_slowpath+0xf49/0x2290 mm/page_alloc.c:4609 __alloc_pages_nodemask+0x3c2/0x5e0 mm/page_alloc.c:4822 __alloc_pages include/linux/gfp.h:504 [inline] __alloc_pages_node include/linux/gfp.h:517 [inline] alloc_pages_vma+0x916/0xd10 mm/mempolicy.c:2239 mpol_shared_policy_lookup+0x15e/0x200 mm/mempolicy.c:2452 shmem_alloc_hugepage mm/shmem.c:1469 [inline] shmem_alloc_and_acct_page+0x61f/0xbe0 mm/shmem.c:1509 shmem_getpage_gfp+0x932/0x3120 mm/shmem.c:1825 iov_iter_advance+0x202/0xf30 lib/iov_iter.c:1074 shmem_getpage mm/shmem.c:154 [inline] shmem_write_begin+0xcd/0x1a0 mm/shmem.c:2486 generic_perform_write+0x23b/0x4e0 mm/filemap.c:3302 __generic_file_write_iter+0x22b/0x4e0 mm/filemap.c:3431 atomic64_set include/asm-generic/atomic-instrumented.h:854 [inline] atomic_long_set include/asm-generic/atomic-long.h:40 [inline] rwsem_set_owner kernel/locking/rwsem.c:176 [inline] __down_write kernel/locking/rwsem.c:1391 [inline] down_write+0xcd/0x130 kernel/locking/rwsem.c:1532 generic_file_write_iter+0x4a6/0x650 mm/filemap.c:3463 call_write_iter include/linux/fs.h:1907 [inline] new_sync_write fs/read_write.c:484 [inline] __vfs_write+0x54c/0x710 fs/read_write.c:497 vfs_write+0x274/0x580 fs/read_write.c:559 ksys_write+0x11b/0x220 fs/read_write.c:612 do_syscall_64+0xf3/0x1b0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 INFO: task syz-executor.2:28882 blocked for more than 144 seconds. Not tainted 5.7.0-rc2-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.2 D28608 28882 7221 0x00004004 Call Trace: context_switch kernel/sched/core.c:3372 [inline] __schedule+0x805/0xc90 kernel/sched/core.c:4088 schedule+0x188/0x220 kernel/sched/core.c:4163 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:4222 __mutex_lock_common+0x129f/0x2fc0 kernel/locking/mutex.c:1033 kvm_set_memory_region arch/x86/kvm/../../../virt/kvm/kvm_main.c:1320 [inline] kvm_vm_ioctl_set_memory_region arch/x86/kvm/../../../virt/kvm/kvm_main.c:1333 [inline] kvm_vm_ioctl+0x923/0x2530 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3604 __mutex_lock kernel/locking/mutex.c:1103 [inline] mutex_lock_nested+0x1a/0x20 kernel/locking/mutex.c:1118 kvm_set_memory_region arch/x86/kvm/../../../virt/kvm/kvm_main.c:1320 [inline] kvm_vm_ioctl_set_memory_region arch/x86/kvm/../../../virt/kvm/kvm_main.c:1333 [inline] kvm_vm_ioctl+0x923/0x2530 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3604 do_vfs_ioctl+0x6ea/0x1910 fs/ioctl.c:741 kvm_stat_data_clear+0x340/0x340 arch/x86/kvm/../../../virt/kvm/kvm_main.c:4403 vfs_ioctl fs/ioctl.c:47 [inline] ksys_ioctl fs/ioctl.c:763 [inline] __do_sys_ioctl fs/ioctl.c:772 [inline] __se_sys_ioctl+0xf9/0x160 fs/ioctl.c:770 do_syscall_64+0xf3/0x1b0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 INFO: task syz-executor.2:28888 blocked for more than 144 seconds. Not tainted 5.7.0-rc2-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.2 D29584 28888 7221 0x00004004 Call Trace: context_switch kernel/sched/core.c:3372 [inline] __schedule+0x805/0xc90 kernel/sched/core.c:4088 schedule+0x188/0x220 kernel/sched/core.c:4163 schedule_timeout+0x43/0x250 kernel/time/timer.c:1874 mark_held_locks kernel/locking/lockdep.c:3628 [inline] __trace_hardirqs_on_caller kernel/locking/lockdep.c:3657 [inline] lockdep_hardirqs_on+0x4a4/0x8a0 kernel/locking/lockdep.c:3702 __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:168 [inline] _raw_spin_unlock_irq+0x1f/0x80 kernel/locking/spinlock.c:199 do_wait_for_common+0x232/0x370 kernel/sched/completion.c:85 console_conditional_schedule+0x30/0x30 __wait_for_common kernel/sched/completion.c:106 [inline] wait_for_common kernel/sched/completion.c:117 [inline] wait_for_completion+0x43/0x50 kernel/sched/completion.c:138 __synchronize_srcu+0x1ba/0x240 kernel/rcu/srcutree.c:922 kmalloc include/linux/slab.h:560 [inline] kvm_io_bus_register_dev+0x154/0x610 arch/x86/kvm/../../../virt/kvm/kvm_main.c:4207 rcu_read_lock_any_held+0x1a0/0x1a0 arch/x86/include/asm/paravirt.h:754 kvm_io_bus_register_dev+0x4ed/0x610 arch/x86/kvm/../../../virt/kvm/kvm_main.c:4228 kvm_vm_ioctl_register_coalesced_mmio+0x1a1/0x330 arch/x86/kvm/../../../virt/kvm/coalesced_mmio.c:156 kvm_vm_ioctl+0x629/0x2530 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3634 do_vfs_ioctl+0x6ea/0x1910 fs/ioctl.c:741 kvm_stat_data_clear+0x340/0x340 arch/x86/kvm/../../../virt/kvm/kvm_main.c:4403 vfs_ioctl fs/ioctl.c:47 [inline] ksys_ioctl fs/ioctl.c:763 [inline] __do_sys_ioctl fs/ioctl.c:772 [inline] __se_sys_ioctl+0xf9/0x160 fs/ioctl.c:770 do_syscall_64+0xf3/0x1b0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 Showing all locks held in the system: 2 locks held by kworker/u4:2/56: #0: ffff8880aa434138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: spin_unlock_irq include/linux/spinlock.h:403 [inline] #0: ffff8880aa434138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x6df/0xfd0 kernel/workqueue.c:2241 #1: ffffc90000f17d80 ((reaper_work).work){+.+.}-{0:0}, at: process_one_work+0x71e/0xfd0 kernel/workqueue.c:2243 2 locks held by kworker/u4:5/245: #0: ffff8880aa434138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: spin_unlock_irq include/linux/spinlock.h:403 [inline] #0: ffff8880aa434138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x6df/0xfd0 kernel/workqueue.c:2241 #1: ffffc90001aa7d80 (connector_reaper_work){+.+.}-{0:0}, at: process_one_work+0x71e/0xfd0 kernel/workqueue.c:2243 1 lock held by khungtaskd/1144: #0: ffffffff892e8550 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 net/mptcp/pm_netlink.c:858 2 locks held by kworker/0:3/3151: 1 lock held by in:imklog/6710: #0: ffff88809aa271b0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x25d/0x2f0 fs/file.c:826 4 locks held by syz-executor.5/28873: #0: ffff888090610930 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x25d/0x2f0 fs/file.c:826 #1: ffff8880a8ca8450 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2908 [inline] #1: ffff8880a8ca8450 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x253/0x580 fs/read_write.c:558 #2: ffff88803f5e0b50 (&sb->s_type->i_mutex_key#16){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:797 [inline] #2: ffff88803f5e0b50 (&sb->s_type->i_mutex_key#16){+.+.}-{3:3}, at: generic_file_write_iter+0x85/0x650 mm/filemap.c:3460 #3: ffffffff89317528 (pcpu_drain_mutex){+.+.}-{3:3}, at: drain_all_pages+0x54/0x630 mm/page_alloc.c:2950 1 lock held by syz-executor.2/28882: #0: ffffc900160390a8 (&kvm->slots_lock){+.+.}-{3:3}, at: kvm_set_memory_region arch/x86/kvm/../../../virt/kvm/kvm_main.c:1320 [inline] #0: ffffc900160390a8 (&kvm->slots_lock){+.+.}-{3:3}, at: kvm_vm_ioctl_set_memory_region arch/x86/kvm/../../../virt/kvm/kvm_main.c:1333 [inline] #0: ffffc900160390a8 (&kvm->slots_lock){+.+.}-{3:3}, at: kvm_vm_ioctl+0x923/0x2530 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3604 1 lock held by syz-executor.2/28888: #0: ffffc900160390a8 (&kvm->slots_lock){+.+.}-{3:3}, at: kvm_vm_ioctl_register_coalesced_mmio+0x121/0x330 arch/x86/kvm/../../../virt/kvm/coalesced_mmio.c:155 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1144 Comm: khungtaskd Not tainted 5.7.0-rc2-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+0x1e9/0x30e lib/dump_stack.c:118 nmi_cpu_backtrace+0x9f/0x180 lib/nmi_backtrace.c:101 arch_trigger_cpumask_backtrace+0x10/0x10 arch/x86/kernel/apic/hw_nmi.c:38 nmi_trigger_cpumask_backtrace+0x16a/0x280 lib/nmi_backtrace.c:62 check_hung_uninterruptible_tasks kernel/hung_task.c:205 [inline] watchdog+0xd2a/0xd40 kernel/hung_task.c:289 kthread+0x353/0x380 kernel/kthread.c:268 hungtask_pm_notify+0x50/0x50 kernel/hung_task.c:265 kthread_blkcg+0xd0/0xd0 kernel/kthread.c:1247 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 3151 Comm: kworker/0:3 Not tainted 5.7.0-rc2-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: events p9_read_work RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:759 [inline] RIP: 0010:lock_is_held_type+0x25b/0x2e0 kernel/locking/lockdep.c:4973 Code: 48 c1 e8 03 42 80 3c 38 00 74 0c 48 c7 c7 30 b9 2b 89 e8 e8 82 58 00 48 83 3d 70 fc d2 07 00 0f 84 82 00 00 00 4c 89 f7 57 9d <0f> 1f 44 00 00 89 e8 48 83 c4 20 5b 41 5c 41 5d 41 5e 41 5f 5d c3 RSP: 0018:ffffc90000e37818 EFLAGS: 00000282 RAX: 1ffffffff1257726 RBX: 1ffff1101469ed28 RCX: 0000000000000000 RDX: dffffc0000000000 RSI: ffff8880a34f6990 RDI: 0000000000000282 RBP: 0000000000000000 R08: ffffffff8632716f R09: 0000000000000000 R10: ffffed101469ec11 R11: 0000000000000000 R12: ffff8880a34f6944 R13: ffffffff892e8520 R14: 0000000000000282 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f758c296000 CR3: 00000000935d9000 CR4: 00000000001426f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_is_held include/linux/lockdep.h:406 [inline] ___might_sleep+0x83/0x570 kernel/sched/core.c:6771 __mutex_lock_common+0x50/0x2fc0 kernel/locking/mutex.c:935 snd_pcm_oss_read1 sound/core/oss/pcm_oss.c:1528 [inline] snd_pcm_oss_read+0xa2a/0xcf0 sound/core/oss/pcm_oss.c:2742 snd_pcm_oss_read1 sound/core/oss/pcm_oss.c:1490 [inline] snd_pcm_oss_read+0x1cf/0xcf0 sound/core/oss/pcm_oss.c:2742 snd_pcm_oss_read1 sound/core/oss/pcm_oss.c:1528 [inline] snd_pcm_oss_read+0xa2a/0xcf0 sound/core/oss/pcm_oss.c:2742 atomic64_cmpxchg include/asm-generic/atomic-instrumented.h:1463 [inline] atomic_long_cmpxchg_release include/asm-generic/atomic-long.h:424 [inline] __mutex_unlock_slowpath+0x12d/0x580 kernel/locking/mutex.c:1249 __mutex_lock kernel/locking/mutex.c:1103 [inline] mutex_lock_interruptible_nested+0x1a/0x20 kernel/locking/mutex.c:1140 snd_pcm_oss_read1 sound/core/oss/pcm_oss.c:1490 [inline] snd_pcm_oss_read+0x1cf/0xcf0 sound/core/oss/pcm_oss.c:2742 snd_pcm_oss_unregister_minor+0x240/0x240 sound/core/oss/pcm_oss.c:2947 __vfs_read+0xa7/0x700 fs/read_write.c:426 vfs_read+0x1c4/0x400 fs/read_write.c:462 kernel_read+0xa3/0xf0 fs/read_write.c:441 p9_fd_read net/9p/trans_fd.c:263 [inline] p9_read_work+0x322/0xec0 net/9p/trans_fd.c:298 process_one_work+0x76e/0xfd0 kernel/workqueue.c:2268 worker_thread+0xa7f/0x1450 kernel/workqueue.c:2414 kthread+0x353/0x380 kernel/kthread.c:268 rcu_lock_release+0x20/0x20 include/linux/rcupdate.h:213 kthread_blkcg+0xd0/0xd0 kernel/kthread.c:1247 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352