rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (1 ticks this GP) idle=5f3/1/0x4000000000000000 softirq=81619/81619 fqs=0 (detected by 1, t=10502 jiffies, g=109493, q=103) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 22082 Comm: syz-executor.2 Not tainted 5.18.0-rc3-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__this_cpu_preempt_check+0xd/0x20 lib/smp_processor_id.c:66 Code: 00 00 48 c7 c6 a0 b9 26 8a 48 c7 c7 e0 b9 26 8a e9 78 fe ff ff 0f 1f 84 00 00 00 00 00 55 48 89 fd 0f 1f 44 00 00 48 89 ee 5d <48> c7 c7 20 ba 26 8a e9 57 fe ff ff cc cc cc cc cc cc cc 0f 1f 44 RSP: 0018:ffffc90000007d38 EFLAGS: 00000082 RAX: 0000000000000001 RBX: 1ffff92000000faa RCX: ffffffff815d505e RDX: 1ffff1100f57c88b RSI: ffffffff89cc5c80 RDI: ffffffff89cc5c80 RBP: 0000000000000001 R08: 0000000000000000 R09: ffffffff9003390f R10: fffffbfff2006721 R11: 0000000000000001 R12: 0000000000000000 R13: 0000000000000000 R14: ffff8880b9c2a5d8 R15: 0000000000000000 FS: 00005555561bb400(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fa0e599d090 CR3: 0000000079410000 CR4: 0000000000350ef0 Call Trace: lockdep_recursion_finish kernel/locking/lockdep.c:436 [inline] lock_acquire kernel/locking/lockdep.c:5643 [inline] lock_acquire+0x1bb/0x510 kernel/locking/lockdep.c:5606 __raw_spin_lock_irq include/linux/spinlock_api_smp.h:119 [inline] _raw_spin_lock_irq+0x32/0x50 kernel/locking/spinlock.c:170 __run_hrtimer kernel/time/hrtimer.c:1689 [inline] __hrtimer_run_queues+0x243/0xe50 kernel/time/hrtimer.c:1749 hrtimer_interrupt+0x31c/0x790 kernel/time/hrtimer.c:1811 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1086 [inline] __sysvec_apic_timer_interrupt+0x146/0x530 arch/x86/kernel/apic/apic.c:1103 sysvec_apic_timer_interrupt+0x8e/0xc0 arch/x86/kernel/apic/apic.c:1097 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:645 RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0x38/0x70 kernel/locking/spinlock.c:194 Code: 74 24 10 e8 fa c8 fa f7 48 89 ef e8 42 48 fb f7 81 e3 00 02 00 00 75 25 9c 58 f6 c4 02 75 2d 48 85 db 74 01 fb bf 01 00 00 00 23 67 ee f7 65 8b 05 ec 9b 9f 76 85 c0 74 0a 5b 5d c3 e8 00 8e RSP: 0018:ffffc900166e7c50 EFLAGS: 00000206 RAX: 0000000000000002 RBX: 0000000000000200 RCX: 1ffffffff1b6dbd9 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000001 RBP: ffffffff9075f2a0 R08: 0000000000000001 R09: 0000000000000001 R10: ffffffff817f6218 R11: 0000000000000001 R12: 1ffffffff20ebe53 R13: 0000000000000000 R14: dead000000000100 R15: dffffc0000000000 __debug_check_no_obj_freed lib/debugobjects.c:1002 [inline] debug_check_no_obj_freed+0x20c/0x420 lib/debugobjects.c:1023 slab_free_hook mm/slub.c:1703 [inline] slab_free_freelist_hook+0xeb/0x1c0 mm/slub.c:1754 slab_free mm/slub.c:3510 [inline] kmem_cache_free+0xdd/0x5a0 mm/slub.c:3527 __d_free fs/dcache.c:298 [inline] dentry_free+0xde/0x160 fs/dcache.c:375 __dentry_kill+0x4cb/0x640 fs/dcache.c:621 dentry_kill fs/dcache.c:733 [inline] dput+0x806/0xdb0 fs/dcache.c:913 __fput+0x39c/0x9d0 fs/file_table.c:330 task_work_run+0xdd/0x1a0 kernel/task_work.c:164 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop kernel/entry/common.c:169 [inline] exit_to_user_mode_prepare+0x23c/0x250 kernel/entry/common.c:201 __syscall_exit_to_user_mode_work kernel/entry/common.c:283 [inline] syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:294 do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f9253a3bd2b Code: 0f 05 48 3d 00 f0 ff ff 77 45 c3 0f 1f 40 00 48 83 ec 18 89 7c 24 0c e8 63 fc ff ff 8b 7c 24 0c 41 89 c0 b8 03 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 35 44 89 c7 89 44 24 0c e8 a1 fc ff ff 8b 44 RSP: 002b:00007ffe7a0257c0 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000004 RCX: 00007f9253a3bd2b RDX: 00007f9253ba0608 RSI: ffffffffffffffff RDI: 0000000000000003 RBP: 00007f9253b9d960 R08: 0000000000000000 R09: 00007f9253ba0610 R10: 00007ffe7a0258c0 R11: 0000000000000293 R12: 00000000000e2f9b R13: 00007ffe7a0258c0 R14: 00007f9253b9bf60 R15: 0000000000000032 rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g109493 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=0 timer-softirq=54633 rcu: rcu_preempt kthread starved for 10502 jiffies! g109493 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=0 rcu: Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior. rcu: RCU grace-period kthread stack dump: task:rcu_preempt state:I stack:28728 pid: 16 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5073 [inline] __schedule+0xa9a/0x4cc0 kernel/sched/core.c:6388 schedule+0xd2/0x1f0 kernel/sched/core.c:6460 schedule_timeout+0x14a/0x2a0 kernel/time/timer.c:1884 rcu_gp_fqs_loop+0x186/0x810 kernel/rcu/tree.c:1971 rcu_gp_kthread+0x1de/0x320 kernel/rcu/tree.c:2144 kthread+0x2e9/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 22082 Comm: syz-executor.2 Not tainted 5.18.0-rc3-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:match_held_lock+0x70/0xc0 kernel/locking/lockdep.c:5118 Code: 06 48 0f af c2 0f b7 53 20 81 e2 ff 1f 00 00 48 39 d0 0f 94 c0 48 83 c4 08 0f b6 c0 5b c3 31 f6 e8 c5 fe ff ff 48 85 c0 75 b2 <31> c0 48 83 c4 08 5b c3 48 83 c4 08 b8 01 00 00 00 5b c3 e8 88 dc RSP: 0018:ffffc90000007be0 EFLAGS: 00000046 RAX: 0000000000000005 RBX: ffff88807abe4488 RCX: 0000000000000001 RDX: 0000000000000000 RSI: ffffffff8bd81d20 RDI: ffff88807abe4488 RBP: ffffffff8bd81d20 R08: 0000000000000000 R09: ffffffff8db70d17 R10: fffffbfff1b6e1a2 R11: 0000000000000001 R12: ffff88807abe3a00 R13: ffff88807abe4460 R14: 00000000ffffffff R15: ffff88807abe4488 FS: 00005555561bb400(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fa0e599d090 CR3: 0000000079410000 CR4: 0000000000350ef0 Call Trace: __lock_is_held kernel/locking/lockdep.c:5382 [inline] lock_is_held_type+0xa7/0x140 kernel/locking/lockdep.c:5684 lock_is_held include/linux/lockdep.h:283 [inline] rcu_read_lock_sched_held+0x3a/0x70 kernel/rcu/update.c:125 trace_lock_release include/trace/events/lock.h:58 [inline] lock_release+0x522/0x720 kernel/locking/lockdep.c:5652 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:149 [inline] _raw_spin_unlock_irqrestore+0x16/0x70 kernel/locking/spinlock.c:194 debug_object_activate+0x287/0x3e0 lib/debugobjects.c:689 debug_hrtimer_activate kernel/time/hrtimer.c:420 [inline] debug_activate kernel/time/hrtimer.c:475 [inline] enqueue_hrtimer+0x27/0x3e0 kernel/time/hrtimer.c:1084 __run_hrtimer kernel/time/hrtimer.c:1702 [inline] __hrtimer_run_queues+0xb02/0xe50 kernel/time/hrtimer.c:1749 hrtimer_interrupt+0x31c/0x790 kernel/time/hrtimer.c:1811 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1086 [inline] __sysvec_apic_timer_interrupt+0x146/0x530 arch/x86/kernel/apic/apic.c:1103 sysvec_apic_timer_interrupt+0x8e/0xc0 arch/x86/kernel/apic/apic.c:1097 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:645 RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0x38/0x70 kernel/locking/spinlock.c:194 Code: 74 24 10 e8 fa c8 fa f7 48 89 ef e8 42 48 fb f7 81 e3 00 02 00 00 75 25 9c 58 f6 c4 02 75 2d 48 85 db 74 01 fb bf 01 00 00 00 23 67 ee f7 65 8b 05 ec 9b 9f 76 85 c0 74 0a 5b 5d c3 e8 00 8e RSP: 0018:ffffc900166e7c50 EFLAGS: 00000206 RAX: 0000000000000002 RBX: 0000000000000200 RCX: 1ffffffff1b6dbd9 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000001 RBP: ffffffff9075f2a0 R08: 0000000000000001 R09: 0000000000000001 R10: ffffffff817f6218 R11: 0000000000000001 R12: 1ffffffff20ebe53 R13: 0000000000000000 R14: dead000000000100 R15: dffffc0000000000 __debug_check_no_obj_freed lib/debugobjects.c:1002 [inline] debug_check_no_obj_freed+0x20c/0x420 lib/debugobjects.c:1023 slab_free_hook mm/slub.c:1703 [inline] slab_free_freelist_hook+0xeb/0x1c0 mm/slub.c:1754 slab_free mm/slub.c:3510 [inline] kmem_cache_free+0xdd/0x5a0 mm/slub.c:3527 __d_free fs/dcache.c:298 [inline] dentry_free+0xde/0x160 fs/dcache.c:375 __dentry_kill+0x4cb/0x640 fs/dcache.c:621 dentry_kill fs/dcache.c:733 [inline] dput+0x806/0xdb0 fs/dcache.c:913 __fput+0x39c/0x9d0 fs/file_table.c:330 task_work_run+0xdd/0x1a0 kernel/task_work.c:164 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop kernel/entry/common.c:169 [inline] exit_to_user_mode_prepare+0x23c/0x250 kernel/entry/common.c:201 __syscall_exit_to_user_mode_work kernel/entry/common.c:283 [inline] syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:294 do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f9253a3bd2b Code: 0f 05 48 3d 00 f0 ff ff 77 45 c3 0f 1f 40 00 48 83 ec 18 89 7c 24 0c e8 63 fc ff ff 8b 7c 24 0c 41 89 c0 b8 03 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 35 44 89 c7 89 44 24 0c e8 a1 fc ff ff 8b 44 RSP: 002b:00007ffe7a0257c0 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000004 RCX: 00007f9253a3bd2b RDX: 00007f9253ba0608 RSI: ffffffffffffffff RDI: 0000000000000003 RBP: 00007f9253b9d960 R08: 0000000000000000 R09: 00007f9253ba0610 R10: 00007ffe7a0258c0 R11: 0000000000000293 R12: 00000000000e2f9b R13: 00007ffe7a0258c0 R14: 00007f9253b9bf60 R15: 0000000000000032 ---------------- Code disassembly (best guess): 0: 00 00 add %al,(%rax) 2: 48 c7 c6 a0 b9 26 8a mov $0xffffffff8a26b9a0,%rsi 9: 48 c7 c7 e0 b9 26 8a mov $0xffffffff8a26b9e0,%rdi 10: e9 78 fe ff ff jmpq 0xfffffe8d 15: 0f 1f 84 00 00 00 00 nopl 0x0(%rax,%rax,1) 1c: 00 1d: 55 push %rbp 1e: 48 89 fd mov %rdi,%rbp 21: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1) 26: 48 89 ee mov %rbp,%rsi 29: 5d pop %rbp * 2a: 48 c7 c7 20 ba 26 8a mov $0xffffffff8a26ba20,%rdi <-- trapping instruction 31: e9 57 fe ff ff jmpq 0xfffffe8d 36: cc int3 37: cc int3 38: cc int3 39: cc int3 3a: cc int3 3b: cc int3 3c: cc int3 3d: 0f .byte 0xf 3e: 1f (bad) 3f: 44 rex.R