kasan: CONFIG_KASAN_INLINE enabled kasan: GPF could be caused by NULL-ptr deref or user memory access general protection fault: 0000 [#1] SMP KASAN Dumping ftrace buffer: (ftrace buffer empty) Modules linked in: CPU: 0 PID: 3477 Comm: syzkaller089891 Not tainted 4.15.0-rc4-next-20171220+ #77 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__fire_sched_out_preempt_notifiers kernel/sched/core.c:2550 [inline] RIP: 0010:fire_sched_out_preempt_notifiers kernel/sched/core.c:2558 [inline] RIP: 0010:prepare_task_switch kernel/sched/core.c:2594 [inline] RIP: 0010:context_switch kernel/sched/core.c:2765 [inline] RIP: 0010:__schedule+0xdf0/0x2060 kernel/sched/core.c:3376 RSP: 0018:ffff8801c46b6cd0 EFLAGS: 00010806 RAX: 1bd5a00000000022 RBX: ffff8801db22c900 RCX: ffffffff810caeaf RDX: 0000000000000000 RSI: 0000000000000000 RDI: dead000000000110 RBP: ffff8801c46b6ea0 R08: 0000000000000000 R09: 1ffff100388d6d6e R10: ffff8801c46b6b38 R11: 0000000000000001 R12: ffff8801c8910240 R13: dead000000000100 R14: dffffc0000000000 R15: ffff8801c4088300 FS: 00007faf9a8c8700(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007faf9f8d2db8 CR3: 0000000006422005 CR4: 00000000001626f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: preempt_schedule_common+0x22/0x60 kernel/sched/core.c:3515 _cond_resched+0x1d/0x30 kernel/sched/core.c:4852 percpu_down_read_preempt_disable include/linux/percpu-rwsem.h:34 [inline] percpu_down_read include/linux/percpu-rwsem.h:59 [inline] cpus_read_lock+0x21/0x90 kernel/cpu.c:293 __static_key_slow_dec kernel/jump_label.c:213 [inline] static_key_slow_dec+0x4a/0x90 kernel/jump_label.c:228 kvm_arch_vcpu_uninit+0x18e/0x1d0 arch/x86/kvm/x86.c:8252 kvm_vcpu_uninit+0x44/0x90 arch/x86/kvm/../../../virt/kvm/kvm_main.c:312 vmx_free_vcpu+0x1c1/0x260 arch/x86/kvm/vmx.c:9812 kvm_arch_vcpu_free arch/x86/kvm/x86.c:7870 [inline] kvm_free_vcpus arch/x86/kvm/x86.c:8317 [inline] kvm_arch_destroy_vm+0x4a2/0x980 arch/x86/kvm/x86.c:8416 kvm_destroy_vm arch/x86/kvm/../../../virt/kvm/kvm_main.c:728 [inline] kvm_put_kvm+0x695/0xde0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:749 kvm_vm_release+0x42/0x50 arch/x86/kvm/../../../virt/kvm/kvm_main.c:760 __fput+0x327/0x7e0 fs/file_table.c:209 ____fput+0x15/0x20 fs/file_table.c:243 task_work_run+0x199/0x270 kernel/task_work.c:113 exit_task_work include/linux/task_work.h:22 [inline] do_exit+0x9bb/0x1ad0 kernel/exit.c:869 do_group_exit+0x149/0x400 kernel/exit.c:972 get_signal+0x73f/0x16c0 kernel/signal.c:2337 do_signal+0x94/0x1ee0 arch/x86/kernel/signal.c:809 exit_to_usermode_loop+0x258/0x2f0 arch/x86/entry/common.c:161 prepare_exit_to_usermode arch/x86/entry/common.c:195 [inline] syscall_return_slowpath+0x490/0x550 arch/x86/entry/common.c:264 entry_SYSCALL_64_fastpath+0x94/0x96 RIP: 0033:0x44eee7 RSP: 002b:00007faf9a8c7d18 EFLAGS: 00000206 ORIG_RAX: 000000000000001c RAX: 0000000000000000 RBX: 00007faf9a8c8700 RCX: 000000000044eee7 RDX: 0000000000000004 RSI: 00000000007fb000 RDI: 00007faf9a0c8000 RBP: 0000000000000000 R08: 00007faf9a8c8700 R09: 00007faf9a8c8700 R10: 00007faf9a8c8700 R11: 0000000000000206 R12: 0000000000000000 R13: 00007ffdf6a4a8df R14: 00007faf9a8c89c0 R15: 0000000000000000 Code: 08 4c 89 e8 48 c1 e8 03 42 80 3c 30 00 0f 85 ce 0f 00 00 4d 8b 6d 00 4d 85 ed 0f 84 72 f9 ff ff 49 8d 7d 10 48 89 f8 48 c1 e8 03 <42> 80 3c 30 00 74 ac eb a5 49 8d bc 24 28 04 00 00 48 b8 00 00 RIP: __fire_sched_out_preempt_notifiers kernel/sched/core.c:2550 [inline] RSP: ffff8801c46b6cd0 RIP: fire_sched_out_preempt_notifiers kernel/sched/core.c:2558 [inline] RSP: ffff8801c46b6cd0 RIP: prepare_task_switch kernel/sched/core.c:2594 [inline] RSP: ffff8801c46b6cd0 RIP: context_switch kernel/sched/core.c:2765 [inline] RSP: ffff8801c46b6cd0 RIP: __schedule+0xdf0/0x2060 kernel/sched/core.c:3376 RSP: ffff8801c46b6cd0 ====================================================== WARNING: possible circular locking dependency detected 4.15.0-rc4-next-20171220+ #77 Not tainted ------------------------------------------------------ syzkaller089891/3477 is trying to acquire lock: ((console_sem).lock){..-.}, at: [<000000002d8c272c>] down_trylock+0x13/0x70 kernel/locking/semaphore.c:136 but task is already holding lock: (&rq->lock){-.-.}, at: [<000000004723a817>] rq_lock kernel/sched/sched.h:1766 [inline] (&rq->lock){-.-.}, at: [<000000004723a817>] __schedule+0x24e/0x2060 kernel/sched/core.c:3313 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (&rq->lock){-.-.}: __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:144 rq_lock kernel/sched/sched.h:1766 [inline] task_fork_fair+0x7a/0x690 kernel/sched/fair.c:9448 sched_fork+0x435/0xc00 kernel/sched/core.c:2405 copy_process.part.37+0x1758/0x4b60 kernel/fork.c:1770 copy_process kernel/fork.c:1613 [inline] _do_fork+0x1f7/0xf70 kernel/fork.c:2094 kernel_thread+0x34/0x40 kernel/fork.c:2153 rest_init+0x22/0xf0 init/main.c:402 start_kernel+0x7f1/0x819 init/main.c:716 x86_64_start_reservations+0x2a/0x2c arch/x86/kernel/head64.c:378 x86_64_start_kernel+0x77/0x7a arch/x86/kernel/head64.c:359 secondary_startup_64+0xa5/0xb0 arch/x86/kernel/head_64.S:237 -> #1 (&p->pi_lock){-.-.}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x96/0xc0 kernel/locking/spinlock.c:152 try_to_wake_up+0xbc/0x1600 kernel/sched/core.c:1989 wake_up_process+0x10/0x20 kernel/sched/core.c:2152 __up.isra.0+0x1cc/0x2c0 kernel/locking/semaphore.c:262 up+0x13b/0x1d0 kernel/locking/semaphore.c:187 __up_console_sem+0xb2/0x1a0 kernel/printk/printk.c:245 console_unlock+0x538/0xd70 kernel/printk/printk.c:2248 do_con_write+0x106e/0x1f70 drivers/tty/vt/vt.c:2433 con_write+0x25/0xb0 drivers/tty/vt/vt.c:2782 process_output_block drivers/tty/n_tty.c:579 [inline] n_tty_write+0x5ef/0xec0 drivers/tty/n_tty.c:2302 do_tty_write drivers/tty/tty_io.c:949 [inline] tty_write+0x3fa/0x840 drivers/tty/tty_io.c:1033 __vfs_write+0xef/0x970 fs/read_write.c:480 vfs_write+0x189/0x510 fs/read_write.c:544 SYSC_write fs/read_write.c:589 [inline] SyS_write+0xef/0x220 fs/read_write.c:581 entry_SYSCALL_64_fastpath+0x1f/0x96 -> #0 ((console_sem).lock){..-.}: lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:3914 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x96/0xc0 kernel/locking/spinlock.c:152 down_trylock+0x13/0x70 kernel/locking/semaphore.c:136 __down_trylock_console_sem+0xa2/0x1e0 kernel/printk/printk.c:228 console_trylock+0x15/0x100 kernel/printk/printk.c:2065 vprintk_emit+0x49b/0x590 kernel/printk/printk.c:1756 vprintk_default+0x28/0x30 kernel/printk/printk.c:1796 vprintk_func+0x57/0xc0 kernel/printk/printk_safe.c:379 printk+0xaa/0xca kernel/printk/printk.c:1829 kasan_die_handler+0x31/0x3f arch/x86/mm/kasan_init_64.c:242 notifier_call_chain+0x136/0x2c0 kernel/notifier.c:93 __atomic_notifier_call_chain kernel/notifier.c:183 [inline] atomic_notifier_call_chain+0x77/0x140 kernel/notifier.c:193 notify_die+0x18c/0x280 kernel/notifier.c:549 do_general_protection+0x331/0x3e0 arch/x86/kernel/traps.c:557 general_protection+0x2c/0x60 arch/x86/entry/entry_64.S:1242 __fire_sched_out_preempt_notifiers kernel/sched/core.c:2550 [inline] fire_sched_out_preempt_notifiers kernel/sched/core.c:2558 [inline] prepare_task_switch kernel/sched/core.c:2594 [inline] context_switch kernel/sched/core.c:2765 [inline] __schedule+0xdf0/0x2060 kernel/sched/core.c:3376 preempt_schedule_common+0x22/0x60 kernel/sched/core.c:3515 _cond_resched+0x1d/0x30 kernel/sched/core.c:4852 percpu_down_read_preempt_disable include/linux/percpu-rwsem.h:34 [inline] percpu_down_read include/linux/percpu-rwsem.h:59 [inline] cpus_read_lock+0x21/0x90 kernel/cpu.c:293 __static_key_slow_dec kernel/jump_label.c:213 [inline] static_key_slow_dec+0x4a/0x90 kernel/jump_label.c:228 kvm_arch_vcpu_uninit+0x18e/0x1d0 arch/x86/kvm/x86.c:8252 kvm_vcpu_uninit+0x44/0x90 arch/x86/kvm/../../../virt/kvm/kvm_main.c:312 vmx_free_vcpu+0x1c1/0x260 arch/x86/kvm/vmx.c:9812 kvm_arch_vcpu_free arch/x86/kvm/x86.c:7870 [inline] kvm_free_vcpus arch/x86/kvm/x86.c:8317 [inline] kvm_arch_destroy_vm+0x4a2/0x980 arch/x86/kvm/x86.c:8416 kvm_destroy_vm arch/x86/kvm/../../../virt/kvm/kvm_main.c:728 [inline] kvm_put_kvm+0x695/0xde0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:749 kvm_vm_release+0x42/0x50 arch/x86/kvm/../../../virt/kvm/kvm_main.c:760 __fput+0x327/0x7e0 fs/file_table.c:209 ____fput+0x15/0x20 fs/file_table.c:243 task_work_run+0x199/0x270 kernel/task_work.c:113 exit_task_work include/linux/task_work.h:22 [inline] do_exit+0x9bb/0x1ad0 kernel/exit.c:869 do_group_exit+0x149/0x400 kernel/exit.c:972 get_signal+0x73f/0x16c0 kernel/signal.c:2337 do_signal+0x94/0x1ee0 arch/x86/kernel/signal.c:809 exit_to_usermode_loop+0x258/0x2f0 arch/x86/entry/common.c:161 prepare_exit_to_usermode arch/x86/entry/common.c:195 [inline] syscall_return_slowpath+0x490/0x550 arch/x86/entry/common.c:264 entry_SYSCALL_64_fastpath+0x94/0x96 other info that might help us debug this: Chain exists of: (console_sem).lock --> &p->pi_lock --> &rq->lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&rq->lock); lock(&p->pi_lock); lock(&rq->lock); lock((console_sem).lock); *** DEADLOCK *** 2 locks held by syzkaller089891/3477: #0: (&rq->lock){-.-.}, at: [<000000004723a817>] rq_lock kernel/sched/sched.h:1766 [inline] #0: (&rq->lock){-.-.}, at: [<000000004723a817>] __schedule+0x24e/0x2060 kernel/sched/core.c:3313 #1: (rcu_read_lock){....}, at: [<00000000ef659c73>] rcu_read_unlock include/linux/rcupdate.h:682 [inline] #1: (rcu_read_lock){....}, at: [<00000000ef659c73>] atomic_notifier_call_chain+0x0/0x140 kernel/notifier.c:184 stack backtrace: CPU: 0 PID: 3477 Comm: syzkaller089891 Not tainted 4.15.0-rc4-next-20171220+ #77 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x194/0x257 lib/dump_stack.c:53 print_circular_bug.isra.37+0x2cd/0x2dc kernel/locking/lockdep.c:1218 check_prev_add kernel/locking/lockdep.c:1858 [inline] check_prevs_add kernel/locking/lockdep.c:1971 [inline] validate_chain kernel/locking/lockdep.c:2412 [inline] __lock_acquire+0x30a8/0x3e00 kernel/locking/lockdep.c:3426 lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:3914 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x96/0xc0 kernel/locking/spinlock.c:152 down_trylock+0x13/0x70 kernel/locking/semaphore.c:136 __down_trylock_console_sem+0xa2/0x1e0 kernel/printk/printk.c:228 console_trylock+0x15/0x100 kernel/printk/printk.c:2065 vprintk_emit+0x49b/0x590 kernel/printk/printk.c:1756 vprintk_default+0x28/0x30 kernel/printk/printk.c:1796 vprintk_func+0x57/0xc0 kernel/printk/printk_safe.c:379 printk+0xaa/0xca kernel/printk/printk.c:1829 kasan_die_handler+0x31/0x3f arch/x86/mm/kasan_init_64.c:242 notifier_call_chain+0x136/0x2c0 kernel/notifier.c:93 __atomic_notifier_call_chain kernel/notifier.c:183 [inline] atomic_notifier_call_chain+0x77/0x140 kernel/notifier.c:193 notify_die+0x18c/0x280 kernel/notifier.c:549 do_general_protection+0x331/0x3e0 arch/x86/kernel/traps.c:557 general_protection+0x2c/0x60 arch/x86/entry/entry_64.S:1242 RIP: 0010:__fire_sched_out_preempt_notifiers kernel/sched/core.c:2550 [inline] RIP: 0010:fire_sched_out_preempt_notifiers kernel/sched/core.c:2558 [inline] RIP: 0010:prepare_task_switch kernel/sched/core.c:2594 [inline] RIP: 0010:context_switch kernel/sched/core.c:2765 [inline] RIP: 0010:__schedule+0xdf0/0x2060 kernel/sched/core.c:3376 RSP: 0018:ffff8801c46b6cd0 EFLAGS: 00010806 RAX: 1bd5a00000000022 RBX: ffff8801db22c900 RCX: ffffffff810caeaf RDX: 0000000000000000 RSI: 0000000000000000 RDI: dead000000000110 RBP: ffff8801c46b6ea0 R08: 0000000000000000 R09: 1ffff100388d6d6e R10: ffff8801c46b6b38 R11: 0000000000000001 R12: ffff8801c8910240 R13: dead000000000100 R14: dffffc0000000000 R15: ffff8801c4088300 preempt_schedule_common+0x22/0x60 kernel/sched/core.c:3515 _cond_resched+0x1d/0x30 kernel/sched/core.c:4852 percpu_down_read_preempt_disable include/linux/percpu-rwsem.h:34 [inline] percpu_down_read include/linux/percpu-rwsem.h:59 [inline] cpus_read_lock+0x21/0x90 kernel/cpu.c:293 __static_key_slow_dec kernel/jump_label.c:213 [inline] static_key_slow_dec+0x4a/0x90 kernel/jump_label.c:228 kvm_arch_vcpu_uninit+0x18e/0x1d0 arch/x86/kvm/x86.c:8252 kvm_vcpu_uninit+0x44/0x90 arch/x86/kvm/../../../virt/kvm/kvm_main.c:312 vmx_free_vcpu+0x1c1/0x260 arch/x86/kvm/vmx.c:9812 kvm_arch_vcpu_free arch/x86/kvm/x86.c:7870 [inline] kvm_free_vcpus arch/x86/kvm/x86.c:8317 [inline] kvm_arch_destroy_vm+0x4a2/0x980 arch/x86/kvm/x86.c:8416 kvm_destroy_vm arch/x86/kvm/../../../virt/kvm/kvm_main.c:728 [inline] kvm_put_kvm+0x695/0xde0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:749 kvm_vm_release+0x42/0x50 arch/x86/kvm/../../../virt/kvm/kvm_main.c:760 __fput+0x327/0x7e0 fs/file_table.c:209 ____fput+0x15/0x20 fs/file_table.c:243 task_work_run+0x199/0x270 kernel/task_work.c:113 exit_task_work include/linux/task_work.h:22 [inline] do_exit+0x9bb/0x1ad0 kernel/exit.c:869 do_group_exit+0x149/0x400 kernel/exit.c:972 get_signal+0x73f/0x16c0 kernel/signal.c:2337 do_signal+0x94/0x1ee0 arch/x86/kernel/signal.c:809 ? setup_sig Lost 23 message(s)! ---[ end trace f00c54e6145e05b1 ]---