------------[ cut here ]------------ kobject: 'ppp0' (000000001c6dff75): kobject_cleanup, parent (null) kobject: 'ppp0' (000000001c6dff75): calling ktype release ODEBUG: free active (active state 1) object type: rcu_head hint: (null) WARNING: CPU: 0 PID: 30024 at lib/debugobjects.c:329 debug_print_object+0x16a/0x210 lib/debugobjects.c:326 kobject: 'ppp0': free name Kernel panic - not syncing: panic_on_warn set ... CPU: 0 PID: 30024 Comm: syz-executor4 Not tainted 4.19.0-rc7-next-20181015+ #94 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+0x244/0x39d lib/dump_stack.c:113 kobject: 'kvm' (00000000c565bacc): kobject_uevent_env panic+0x2ad/0x55c kernel/panic.c:188 kobject: 'kvm' (00000000c565bacc): fill_kobj_path: path = '/devices/virtual/misc/kvm' __warn.cold.8+0x20/0x45 kernel/panic.c:540 report_bug+0x254/0x2d0 lib/bug.c:186 fixup_bug arch/x86/kernel/traps.c:178 [inline] do_error_trap+0x11b/0x200 arch/x86/kernel/traps.c:271 do_invalid_op+0x36/0x40 arch/x86/kernel/traps.c:290 invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:969 RIP: 0010:debug_print_object+0x16a/0x210 lib/debugobjects.c:326 Code: 41 88 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 92 00 00 00 48 8b 14 dd 80 08 41 88 4c 89 fe 48 c7 c7 20 fe 40 88 e8 36 c3 b3 fd <0f> 0b 83 05 b9 ff 5e 06 01 48 83 c4 18 5b 41 5c 41 5d 41 5e 41 5f RSP: 0018:ffff8801c69e6698 EFLAGS: 00010086 RAX: 0000000000000000 RBX: 0000000000000003 RCX: ffffc9000658e000 RDX: 0000000000040000 RSI: ffffffff81647515 RDI: 0000000000000005 RBP: ffff8801c69e66d8 R08: ffff880177180400 R09: ffffed003b5c3eda R10: ffffed003b5c3eda R11: ffff8801dae1f6d7 R12: 0000000000000001 R13: ffffffff8939a4e0 R14: 0000000000000000 R15: ffffffff884102c0 __debug_check_no_obj_freed lib/debugobjects.c:786 [inline] debug_check_no_obj_freed+0x3ae/0x58d lib/debugobjects.c:818 kmem_cache_free+0x202/0x290 mm/slab.c:3759 free_task_struct kernel/fork.c:163 [inline] free_task+0x16e/0x1f0 kernel/fork.c:457 __put_task_struct+0x2e6/0x620 kernel/fork.c:730 put_task_struct include/linux/sched/task.h:96 [inline] finish_task_switch+0x66b/0x920 kernel/sched/core.c:2715 context_switch kernel/sched/core.c:2834 [inline] __schedule+0x8d7/0x21d0 kernel/sched/core.c:3480 preempt_schedule_irq+0xb9/0x140 kernel/sched/core.c:3707 retint_kernel+0x1b/0x2d RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:761 [inline] RIP: 0010:qlink_free mm/kasan/quarantine.c:150 [inline] RIP: 0010:qlist_free_all+0xf0/0x140 mm/kasan/quarantine.c:166 Code: c7 40 10 00 00 00 00 48 83 c4 08 5b 41 5c 41 5d 41 5e 41 5f 5d c3 e8 2f 5c c1 ff 48 83 3d 37 07 6f 07 00 74 47 48 89 df 57 9d <0f> 1f 44 00 00 eb af 48 89 df e8 21 de 75 ff 48 b9 00 00 00 00 00 RSP: 0018:ffff8801c69e6d68 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff13 RAX: 0000000000000000 RBX: 0000000000000282 RCX: 1ffff1002ee30194 RDX: 0000000000000000 RSI: ffff880177180ca8 RDI: 0000000000000282 RBP: ffff8801c69e6d98 R08: ffff880177180ca0 R09: 0000000000000006 R10: 0000000000000000 R11: ffff880177180400 R12: 0000000000000000 R13: ffff88018c3d0ac0 R14: ffff8801be2b3f80 R15: ffff8801da98ae00 quarantine_reduce+0x163/0x1a0 mm/kasan/quarantine.c:259 kasan_kmalloc+0x9b/0xe0 mm/kasan/kasan.c:538 kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:490 slab_post_alloc_hook mm/slab.h:444 [inline] slab_alloc_node mm/slab.c:3335 [inline] kmem_cache_alloc_node_trace+0x135/0x740 mm/slab.c:3661 __do_kmalloc_node mm/slab.c:3683 [inline] __kmalloc_node+0x3c/0x70 mm/slab.c:3691 kmalloc_node include/linux/slab.h:589 [inline] kvmalloc_node+0x65/0xf0 mm/util.c:423 kvmalloc include/linux/mm.h:577 [inline] kvmalloc_array include/linux/mm.h:595 [inline] kvcalloc include/linux/mm.h:600 [inline] kvm_arch_create_memslot+0xc3/0x570 arch/x86/kvm/x86.c:9051 __kvm_set_memory_region+0x1c2f/0x2c70 arch/x86/kvm/../../../virt/kvm/kvm_main.c:1010 __x86_set_memory_region+0x4b6/0x880 arch/x86/kvm/x86.c:8966 alloc_apic_access_page arch/x86/kvm/vmx.c:5879 [inline] vmx_create_vcpu+0x1ade/0x25c0 arch/x86/kvm/vmx.c:11050 kvm_arch_vcpu_create+0xe5/0x220 arch/x86/kvm/x86.c:8471 kvm_vm_ioctl_create_vcpu arch/x86/kvm/../../../virt/kvm/kvm_main.c:2475 [inline] kvm_vm_ioctl+0x472/0x1d60 arch/x86/kvm/../../../virt/kvm/kvm_main.c:2976 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:501 [inline] do_vfs_ioctl+0x1de/0x1720 fs/ioctl.c:685 ksys_ioctl+0xa9/0xd0 fs/ioctl.c:702 __do_sys_ioctl fs/ioctl.c:709 [inline] __se_sys_ioctl fs/ioctl.c:707 [inline] __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:707 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457569 Code: fd b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 cb b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f44c9c40c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000457569 RDX: 0000000000000000 RSI: 000000000000ae41 RDI: 0000000000000004 RBP: 000000000072bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f44c9c416d4 R13: 00000000004bfc04 R14: 00000000004cfca0 R15: 00000000ffffffff ====================================================== WARNING: possible circular locking dependency detected 4.19.0-rc7-next-20181015+ #94 Not tainted ------------------------------------------------------ syz-executor4/30024 is trying to acquire lock: 000000009d6f6957 ((console_sem).lock){-.-.}, at: down_trylock+0x13/0x70 kernel/locking/semaphore.c:136 but task is already holding lock: 000000009f9b3ee1 (&obj_hash[i].lock){-.-.}, at: __debug_check_no_obj_freed lib/debugobjects.c:777 [inline] 000000009f9b3ee1 (&obj_hash[i].lock){-.-.}, at: debug_check_no_obj_freed+0x17a/0x58d lib/debugobjects.c:818 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (&obj_hash[i].lock){-.-.}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x99/0xd0 kernel/locking/spinlock.c:152 __debug_object_init+0x127/0x1290 lib/debugobjects.c:384 debug_object_init+0x16/0x20 lib/debugobjects.c:432 debug_hrtimer_init kernel/time/hrtimer.c:410 [inline] debug_init kernel/time/hrtimer.c:458 [inline] hrtimer_init+0x97/0x490 kernel/time/hrtimer.c:1308 init_dl_task_timer+0x1b/0x50 kernel/sched/deadline.c:1057 __sched_fork+0x2ae/0x590 kernel/sched/core.c:2166 init_idle+0x75/0x740 kernel/sched/core.c:5382 sched_init+0xb33/0xc02 kernel/sched/core.c:6065 start_kernel+0x4be/0xa2b init/main.c:608 x86_64_start_reservations+0x2e/0x30 arch/x86/kernel/head64.c:472 x86_64_start_kernel+0x76/0x79 arch/x86/kernel/head64.c:451 secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:243 -> #2 (&rq->lock){-.-.}: __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2d/0x40 kernel/locking/spinlock.c:144 rq_lock kernel/sched/sched.h:1127 [inline] task_fork_fair+0xb0/0x6d0 kernel/sched/fair.c:9768 sched_fork+0x443/0xba0 kernel/sched/core.c:2359 copy_process+0x2585/0x8770 kernel/fork.c:1887 _do_fork+0x1cb/0x11c0 kernel/fork.c:2216 kernel_thread+0x34/0x40 kernel/fork.c:2275 rest_init+0x28/0x372 init/main.c:409 arch_call_rest_init+0xe/0x1b start_kernel+0x9f0/0xa2b init/main.c:745 x86_64_start_reservations+0x2e/0x30 arch/x86/kernel/head64.c:472 x86_64_start_kernel+0x76/0x79 arch/x86/kernel/head64.c:451 secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:243 -> #1 (&p->pi_lock){-.-.}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x99/0xd0 kernel/locking/spinlock.c:152 try_to_wake_up+0xd2/0x12e0 kernel/sched/core.c:1965 wake_up_process+0x10/0x20 kernel/sched/core.c:2129 __up.isra.1+0x1c0/0x2a0 kernel/locking/semaphore.c:262 up+0x13c/0x1c0 kernel/locking/semaphore.c:187 __up_console_sem+0xbe/0x1b0 kernel/printk/printk.c:236 console_unlock+0x80c/0x1190 kernel/printk/printk.c:2432 vprintk_emit+0x391/0x990 kernel/printk/printk.c:1922 vprintk_default+0x28/0x30 kernel/printk/printk.c:1964 vprintk_func+0x7e/0x181 kernel/printk/printk_safe.c:398 printk+0xa7/0xcf kernel/printk/printk.c:1997 check_stack_usage kernel/exit.c:755 [inline] do_exit.cold.18+0x57/0x16f kernel/exit.c:916 do_group_exit+0x177/0x440 kernel/exit.c:970 __do_sys_exit_group kernel/exit.c:981 [inline] __se_sys_exit_group kernel/exit.c:979 [inline] __x64_sys_exit_group+0x3e/0x50 kernel/exit.c:979 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe -> #0 ((console_sem).lock){-.-.}: lock_acquire+0x1ed/0x520 kernel/locking/lockdep.c:3845 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x99/0xd0 kernel/locking/spinlock.c:152 down_trylock+0x13/0x70 kernel/locking/semaphore.c:136 __down_trylock_console_sem+0xae/0x1f0 kernel/printk/printk.c:219 console_trylock+0x15/0xa0 kernel/printk/printk.c:2247 console_trylock_spinning kernel/printk/printk.c:1653 [inline] vprintk_emit+0x372/0x990 kernel/printk/printk.c:1921 vprintk_default+0x28/0x30 kernel/printk/printk.c:1964 vprintk_func+0x7e/0x181 kernel/printk/printk_safe.c:398 printk+0xa7/0xcf kernel/printk/printk.c:1997 __warn_printk+0x8c/0xe0 kernel/panic.c:594 debug_print_object+0x16a/0x210 lib/debugobjects.c:326 __debug_check_no_obj_freed lib/debugobjects.c:786 [inline] debug_check_no_obj_freed+0x3ae/0x58d lib/debugobjects.c:818 kmem_cache_free+0x202/0x290 mm/slab.c:3759 free_task_struct kernel/fork.c:163 [inline] free_task+0x16e/0x1f0 kernel/fork.c:457 __put_task_struct+0x2e6/0x620 kernel/fork.c:730 put_task_struct include/linux/sched/task.h:96 [inline] finish_task_switch+0x66b/0x920 kernel/sched/core.c:2715 context_switch kernel/sched/core.c:2834 [inline] __schedule+0x8d7/0x21d0 kernel/sched/core.c:3480 preempt_schedule_irq+0xb9/0x140 kernel/sched/core.c:3707 retint_kernel+0x1b/0x2d arch_local_irq_restore arch/x86/include/asm/paravirt.h:761 [inline] qlink_free mm/kasan/quarantine.c:150 [inline] qlist_free_all+0xf0/0x140 mm/kasan/quarantine.c:166 quarantine_reduce+0x163/0x1a0 mm/kasan/quarantine.c:259 kasan_kmalloc+0x9b/0xe0 mm/kasan/kasan.c:538 kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:490 slab_post_alloc_hook mm/slab.h:444 [inline] slab_alloc_node mm/slab.c:3335 [inline] kmem_cache_alloc_node_trace+0x135/0x740 mm/slab.c:3661 __do_kmalloc_node mm/slab.c:3683 [inline] __kmalloc_node+0x3c/0x70 mm/slab.c:3691 kmalloc_node include/linux/slab.h:589 [inline] kvmalloc_node+0x65/0xf0 mm/util.c:423 kvmalloc include/linux/mm.h:577 [inline] kvmalloc_array include/linux/mm.h:595 [inline] kvcalloc include/linux/mm.h:600 [inline] kvm_arch_create_memslot+0xc3/0x570 arch/x86/kvm/x86.c:9051 __kvm_set_memory_region+0x1c2f/0x2c70 arch/x86/kvm/../../../virt/kvm/kvm_main.c:1010 __x86_set_memory_region+0x4b6/0x880 arch/x86/kvm/x86.c:8966 alloc_apic_access_page arch/x86/kvm/vmx.c:5879 [inline] vmx_create_vcpu+0x1ade/0x25c0 arch/x86/kvm/vmx.c:11050 kvm_arch_vcpu_create+0xe5/0x220 arch/x86/kvm/x86.c:8471 kvm_vm_ioctl_create_vcpu arch/x86/kvm/../../../virt/kvm/kvm_main.c:2475 [inline] kvm_vm_ioctl+0x472/0x1d60 arch/x86/kvm/../../../virt/kvm/kvm_main.c:2976 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:501 [inline] do_vfs_ioctl+0x1de/0x1720 fs/ioctl.c:685 ksys_ioctl+0xa9/0xd0 fs/ioctl.c:702 __do_sys_ioctl fs/ioctl.c:709 [inline] __se_sys_ioctl fs/ioctl.c:707 [inline] __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:707 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe other info that might help us debug this: Chain exists of: (console_sem).lock --> &rq->lock --> &obj_hash[i].lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&obj_hash[i].lock); lock(&rq->lock); lock(&obj_hash[i].lock); lock((console_sem).lock); *** DEADLOCK *** 3 locks held by syz-executor4/30024: #0: 00000000c799a8c6 (&kvm->slots_lock){+.+.}, at: alloc_apic_access_page arch/x86/kvm/vmx.c:5876 [inline] #0: 00000000c799a8c6 (&kvm->slots_lock){+.+.}, at: vmx_create_vcpu+0x164d/0x25c0 arch/x86/kvm/vmx.c:11050 #1: 00000000bbc0cfda (remove_cache_srcu){....}, at: quarantine_reduce+0x61/0x1a0 mm/kasan/quarantine.c:261 #2: 000000009f9b3ee1 (&obj_hash[i].lock){-.-.}, at: __debug_check_no_obj_freed lib/debugobjects.c:777 [inline] #2: 000000009f9b3ee1 (&obj_hash[i].lock){-.-.}, at: debug_check_no_obj_freed+0x17a/0x58d lib/debugobjects.c:818 stack backtrace: CPU: 0 PID: 30024 Comm: syz-executor4 Not tainted 4.19.0-rc7-next-20181015+ #94 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+0x244/0x39d lib/dump_stack.c:113 print_circular_bug.isra.35.cold.54+0x1bd/0x27d kernel/locking/lockdep.c:1222 check_prev_add kernel/locking/lockdep.c:1864 [inline] check_prevs_add kernel/locking/lockdep.c:1977 [inline] validate_chain kernel/locking/lockdep.c:2348 [inline] __lock_acquire+0x3399/0x4c20 kernel/locking/lockdep.c:3342 lock_acquire+0x1ed/0x520 kernel/locking/lockdep.c:3845 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x99/0xd0 kernel/locking/spinlock.c:152 down_trylock+0x13/0x70 kernel/locking/semaphore.c:136 __down_trylock_console_sem+0xae/0x1f0 kernel/printk/printk.c:219 console_trylock+0x15/0xa0 kernel/printk/printk.c:2247 console_trylock_spinning kernel/printk/printk.c:1653 [inline] vprintk_emit+0x372/0x990 kernel/printk/printk.c:1921 vprintk_default+0x28/0x30 kernel/printk/printk.c:1964 vprintk_func+0x7e/0x181 kernel/printk/printk_safe.c:398 printk+0xa7/0xcf kernel/printk/printk.c:1997 __warn_printk+0x8c/0xe0 kernel/panic.c:594 debug_print_object+0x16a/0x210 lib/debugobjects.c:326 __debug_check_no_obj_freed lib/debugobjects.c:786 [inline] debug_check_no_obj_freed+0x3ae/0x58d lib/debugobjects.c:818 kmem_cache_free+0x202/0x290 mm/slab.c:3759 free_task_struct kernel/fork.c:163 [inline] free_task+0x16e/0x1f0 kernel/fork.c:457 __put_task_struct+0x2e6/0x620 kernel/fork.c:730 put_task_struct include/linux/sched/task.h:96 [inline] finish_task_switch+0x66b/0x920 kernel/sched/core.c:2715 context_switch kernel/sched/core.c:2834 [inline] __schedule+0x8d7/0x21d0 kernel/sched/core.c:3480 preempt_schedule_irq+0xb9/0x140 kernel/sched/core.c:3707 retint_kernel+0x1b/0x2d RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:761 [inline] RIP: 0010:qlink_free mm/kasan/quarantine.c:150 [inline] RIP: 0010:qlist_free_all+0xf0/0x140 mm/kasan/quarantine.c:166 Code: c7 40 10 00 00 00 00 48 83 c4 08 5b 41 5c 41 5d 41 5e 41 5f 5d c3 e8 2f 5c c1 ff 48 83 3d 37 07 6f 07 00 74 47 48 89 df 57 9d <0f> 1f 44 00 00 eb af 48 89 df e8 21 de 75 ff 48 b9 00 00 00 00 00 RSP: 0018:ffff8801c69e6d68 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff13 RAX: 0000000000000000 RBX: 0000000000000282 RCX: 1ffff1002ee30194 RDX: 0000000000000000 RSI: ffff880177180ca8 RDI: 0000000000000282 RBP: ffff8801c69e6d98 R08: ffff880177180ca0 R09: 0000000000000006 R10: 0000000000000000 R11: ffff880177180400 R12: 0000000000000000 R13: ffff88018c3d0ac0 R14: ffff8801be2b3 Lost 114 message(s)! Kernel Offset: disabled Rebooting in 86400 seconds..