kasan: CONFIG_KASAN_INLINE enabled kasan: GPF could be caused by NULL-ptr deref or user memory access kasan: CONFIG_KASAN_INLINE enabled general protection fault: 0000 [#1] SMP KASAN kasan: GPF could be caused by NULL-ptr deref or user memory access Dumping ftrace buffer: (ftrace buffer empty) Modules linked in: CPU: 1 PID: 6842 Comm: syz-executor6 Not tainted 4.16.0-rc6+ #1 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__debug_check_no_obj_freed lib/debugobjects.c:737 [inline] RIP: 0010:debug_check_no_obj_freed+0x239/0xf1f lib/debugobjects.c:774 RSP: 0018:ffff88016ec46fc8 EFLAGS: 00010002 RAX: 0000000000000009 RBX: 078e0401078e0401 RCX: 0000000000000082 RDX: 00f1c08020f1c080 RSI: 1ffff10032698561 RDI: ffff8801934c2b08 RBP: ffff88016ec47198 R08: 1ffff1002dd88d37 R09: ffff8801cf4c8ca0 R10: ffffed002dd88e1e R11: ffff8801cf4c8d68 R12: ffffed002dd88e0e R13: ffff88016ec47170 R14: 078e0401078e0401 R15: dffffc0000000000 FS: 00007f126fd20700(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fd936d15db8 CR3: 0000000006e22003 CR4: 00000000001606e0 DR0: 0000000020000000 DR1: 0000000020000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600 Call Trace: kmem_cache_free+0x24c/0x2a0 mm/slab.c:3742 remove_vma+0x162/0x1b0 mm/mmap.c:176 exit_mmap+0x311/0x500 mm/mmap.c:3049 __mmput kernel/fork.c:960 [inline] mmput+0x223/0x6d0 kernel/fork.c:981 exit_mm kernel/exit.c:544 [inline] do_exit+0x90a/0x1ad0 kernel/exit.c:852 do_group_exit+0x149/0x400 kernel/exit.c:968 get_signal+0x73a/0x16d0 kernel/signal.c:2469 do_signal+0x90/0x1e90 arch/x86/kernel/signal.c:809 exit_to_usermode_loop+0x258/0x2f0 arch/x86/entry/common.c:162 prepare_exit_to_usermode arch/x86/entry/common.c:196 [inline] syscall_return_slowpath arch/x86/entry/common.c:265 [inline] do_syscall_64+0x6ec/0x940 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x454879 RSP: 002b:00007f126fd1fce8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 000000000072bf80 RCX: 0000000000454879 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 000000000072bf80 RBP: 000000000072bf80 R08: 0000000000000000 R09: 000000000072bf58 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffd49a7a50f R14: 00007f126fd209c0 R15: 0000000000000001 Code: 4d 85 f6 0f 84 d7 04 00 00 4d 8d 55 80 4c 8b 9d 80 fe ff ff 4c 8b 8d 88 fe ff ff 31 c0 49 c1 ea 03 4d 01 fa 4c 89 f2 48 c1 ea 03 <42> 80 3c 3a 00 0f 85 06 05 00 00 49 8d 7e 18 83 c0 01 49 8b 16 RIP: __debug_check_no_obj_freed lib/debugobjects.c:737 [inline] RSP: ffff88016ec46fc8 RIP: debug_check_no_obj_freed+0x239/0xf1f lib/debugobjects.c:774 RSP: ffff88016ec46fc8 ====================================================== WARNING: possible circular locking dependency detected 4.16.0-rc6+ #1 Not tainted ------------------------------------------------------ syz-executor6/6842 is trying to acquire lock: ((console_sem).lock){-.-.}, at: [<00000000936a11ae>] down_trylock+0x13/0x70 kernel/locking/semaphore.c:136 but task is already holding lock: (&obj_hash[i].lock){-.-.}, at: [<000000001e00f428>] __debug_check_no_obj_freed lib/debugobjects.c:736 [inline] (&obj_hash[i].lock){-.-.}, at: [<000000001e00f428>] debug_check_no_obj_freed+0x1e9/0xf1f lib/debugobjects.c:774 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+0x96/0xc0 kernel/locking/spinlock.c:152 __debug_object_init+0x109/0x1040 lib/debugobjects.c:343 debug_object_init+0x17/0x20 lib/debugobjects.c:391 debug_hrtimer_init kernel/time/hrtimer.c:410 [inline] debug_init kernel/time/hrtimer.c:458 [inline] hrtimer_init+0x8c/0x410 kernel/time/hrtimer.c:1259 init_dl_task_timer+0x1b/0x50 kernel/sched/deadline.c:1060 __sched_fork+0x2bb/0xb60 kernel/sched/core.c:2189 init_idle+0x75/0x820 kernel/sched/core.c:5352 sched_init+0xb19/0xc43 kernel/sched/core.c:6049 start_kernel+0x452/0x819 init/main.c:586 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:239 -> #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:1760 [inline] task_fork_fair+0x7a/0x690 kernel/sched/fair.c:9471 sched_fork+0x450/0xc10 kernel/sched/core.c:2405 copy_process.part.38+0x1758/0x4b60 kernel/fork.c:1763 copy_process kernel/fork.c:1606 [inline] _do_fork+0x1f7/0xf70 kernel/fork.c:2087 kernel_thread+0x34/0x40 kernel/fork.c:2146 rest_init+0x22/0xf0 init/main.c:403 start_kernel+0x7f1/0x819 init/main.c:717 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:239 -> #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/0x15f0 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:242 console_unlock+0x5af/0xfb0 kernel/printk/printk.c:2417 con_flush_chars+0x6e/0x80 drivers/tty/vt/vt.c:2863 n_tty_write+0x71b/0xec0 drivers/tty/n_tty.c:2325 do_tty_write drivers/tty/tty_io.c:958 [inline] tty_write+0x3fa/0x840 drivers/tty/tty_io.c:1042 __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 do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x42/0xb7 -> #0 ((console_sem).lock){-.-.}: lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:3920 __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:225 console_trylock+0x15/0x70 kernel/printk/printk.c:2229 console_trylock_spinning kernel/printk/printk.c:1643 [inline] vprintk_emit+0x5b5/0xb90 kernel/printk/printk.c:1906 vprintk_default+0x28/0x30 kernel/printk/printk.c:1947 vprintk_func+0x57/0xc0 kernel/printk/printk_safe.c:379 printk+0xaa/0xca kernel/printk/printk.c:1980 kasan_die_handler+0x31/0x3f arch/x86/mm/kasan_init_64.c:247 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:558 general_protection+0x25/0x50 arch/x86/entry/entry_64.S:1150 __debug_check_no_obj_freed lib/debugobjects.c:737 [inline] debug_check_no_obj_freed+0x239/0xf1f lib/debugobjects.c:774 kmem_cache_free+0x24c/0x2a0 mm/slab.c:3742 remove_vma+0x162/0x1b0 mm/mmap.c:176 exit_mmap+0x311/0x500 mm/mmap.c:3049 __mmput kernel/fork.c:960 [inline] mmput+0x223/0x6d0 kernel/fork.c:981 exit_mm kernel/exit.c:544 [inline] do_exit+0x90a/0x1ad0 kernel/exit.c:852 do_group_exit+0x149/0x400 kernel/exit.c:968 get_signal+0x73a/0x16d0 kernel/signal.c:2469 do_signal+0x90/0x1e90 arch/x86/kernel/signal.c:809 exit_to_usermode_loop+0x258/0x2f0 arch/x86/entry/common.c:162 prepare_exit_to_usermode arch/x86/entry/common.c:196 [inline] syscall_return_slowpath arch/x86/entry/common.c:265 [inline] do_syscall_64+0x6ec/0x940 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 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 *** 2 locks held by syz-executor6/6842: #0: (&obj_hash[i].lock){-.-.}, at: [<000000001e00f428>] __debug_check_no_obj_freed lib/debugobjects.c:736 [inline] #0: (&obj_hash[i].lock){-.-.}, at: [<000000001e00f428>] debug_check_no_obj_freed+0x1e9/0xf1f lib/debugobjects.c:774 #1: (rcu_read_lock){....}, at: [<000000008e0e18fc>] rcu_read_unlock include/linux/rcupdate.h:682 [inline] #1: (rcu_read_lock){....}, at: [<000000008e0e18fc>] atomic_notifier_call_chain+0x0/0x140 kernel/notifier.c:184 stack backtrace: CPU: 1 PID: 6842 Comm: syz-executor6 Not tainted 4.16.0-rc6+ #1 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+0x194/0x24d lib/dump_stack.c:53 print_circular_bug.isra.38+0x2cd/0x2dc kernel/locking/lockdep.c:1223 check_prev_add kernel/locking/lockdep.c:1863 [inline] check_prevs_add kernel/locking/lockdep.c:1976 [inline] validate_chain kernel/locking/lockdep.c:2417 [inline] __lock_acquire+0x30a8/0x3e00 kernel/locking/lockdep.c:3431 lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:3920 __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:225 console_trylock+0x15/0x70 kernel/printk/printk.c:2229 console_trylock_spinning kernel/printk/printk.c:1643 [inline] vprintk_emit+0x5b5/0xb90 kernel/printk/printk.c:1906 vprintk_default+0x28/0x30 kernel/printk/printk.c:1947 vprintk_func+0x57/0xc0 kernel/printk/printk_safe.c:379 printk+0xaa/0xca kernel/printk/printk.c:1980 kasan_die_handler+0x31/0x3f arch/x86/mm/kasan_init_64.c:247 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:558 general_protection+0x25/0x50 arch/x86/entry/entry_64.S:1150 RIP: 0010:__debug_check_no_obj_freed lib/debugobjects.c:737 [inline] RIP: 0010:debug_check_no_obj_freed+0x239/0xf1f lib/debugobjects.c:774 RSP: 0018:ffff88016ec46fc8 EFLAGS: 00010002 RAX: 0000000000000009 RBX: 078e0401078e0401 RCX: 0000000000000082 RDX: 00f1c08020f1c080 RSI: 1ffff10032698561 RDI: ffff8801934c2b08 RBP: ffff88016ec47198 R08: 1ffff1002dd88d37 R09: ffff8801cf4c8ca0 R10: ffffed002dd88e1e R11: ffff8801cf4c8d68 R12: ffffed002dd88e0e R13: ffff88016ec47170 R14: 078e0401078e0401 R15: dffffc0000000000 kmem_cache_free+0x24c/0x2a0 mm/slab.c:3742 remove_vma+0x162/0x1b0 mm/mmap.c:176 exit_mmap+0x311/0x500 mm/mmap.c:3049 __mmput kernel/fork.c:960 [inline] mmput+0x223/0x6d0 kernel/fork.c:981 exit_mm kernel/exit.c:544 [inline] do_exit+0x90a/0x1ad0 kernel/exit.c:852 do_group_exit+0x149/0x400 kernel/exit.c:968 get_signal+0x73a/0x16d0 kernel/signal.c:2469 do_signal+0x90/0x1e90 arch/x86/kernel/signal.c:809 exit_to_usermode_loop+0x258/0x2f0 arch/x86/entry/common.c:162 ? do_syscall Lost 18 message(s)! ---[ end trace a5be101c0e3795fb ]--- general protection fault: 0000 [#2] SMP KASAN Dumping ftrace buffer: