rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (0 ticks this GP) idle=bf7/1/0x4000000000000000 softirq=299618/299618 fqs=0 (detected by 0, t=10502 jiffies, g=470441, q=56) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 30493 Comm: syz-executor.4 Not tainted 5.17.0-rc8-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:rcu_rnp_online_cpus kernel/rcu/tree.c:221 [inline] RIP: 0010:rcu_lockdep_current_cpu_online kernel/rcu/tree.c:1178 [inline] RIP: 0010:rcu_lockdep_current_cpu_online+0xc5/0x150 kernel/rcu/tree.c:1167 Code: 48 89 fa 48 c1 ea 03 80 3c 02 00 75 7b 48 8d 7d 70 48 8b 5b 20 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 80 3c 02 00 <75> 66 48 8b 45 70 48 85 c3 74 11 b8 01 00 00 00 65 ff 0d 44 46 9e RSP: 0018:ffffc90000dc0d38 EFLAGS: 00000046 RAX: dffffc0000000000 RBX: 0000000000000002 RCX: ffffffff815d8c01 RDX: 1ffffffff1771c66 RSI: 0000000000010005 RDI: ffffffff8bb8e330 RBP: ffffffff8bb8e2c0 R08: 0000000000000000 R09: ffffffff8d943057 R10: fffffbfff1b2860a R11: 0000000000000000 R12: 0000000000000001 R13: ffff8880b9d2a700 R14: ffff8880b9d2a600 R15: ffffffff8763d4c0 FS: 00007f24495dc700(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f244ad7a028 CR3: 00000000486a6000 CR4: 0000000000350ee0 Call Trace: rcu_read_lock_held_common kernel/rcu/update.c:112 [inline] rcu_read_lock_held_common kernel/rcu/update.c:102 [inline] rcu_read_lock_sched_held+0x25/0x70 kernel/rcu/update.c:123 trace_lock_release include/trace/events/lock.h:58 [inline] lock_release+0x522/0x720 kernel/locking/lockdep.c:5650 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:149 [inline] _raw_spin_unlock_irqrestore+0x16/0x70 kernel/locking/spinlock.c:194 __run_hrtimer kernel/time/hrtimer.c:1681 [inline] __hrtimer_run_queues+0x51a/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:638 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 ea 81 0e f8 48 89 ef e8 42 00 0f f8 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 f3 b7 01 f8 65 8b 05 1c 66 b3 76 85 c0 74 0a 5b 5d c3 e8 30 f4 RSP: 0018:ffffc900049dfb98 EFLAGS: 00000206 RAX: 0000000000000006 RBX: 0000000000000200 RCX: 1ffffffff1b28099 RDX: 0000000000000000 RSI: 0000000000000002 RDI: 0000000000000001 RBP: ffff888047d04380 R08: 0000000000000001 R09: 0000000000000001 R10: ffffffff817efe18 R11: 0000000000000000 R12: 0000000000000206 R13: ffff888047d03a14 R14: ffff888047d04380 R15: ffff8880b9c39c40 try_to_wake_up+0x560/0x1510 kernel/sched/core.c:4135 wake_up_process kernel/sched/core.c:4217 [inline] wake_up_q+0x7e/0xf0 kernel/sched/core.c:964 futex_wake+0x3e9/0x490 kernel/futex/waitwake.c:184 do_futex+0x266/0x300 kernel/futex/syscalls.c:111 __do_sys_futex kernel/futex/syscalls.c:183 [inline] __se_sys_futex kernel/futex/syscalls.c:164 [inline] __x64_sys_futex+0x1b0/0x4a0 kernel/futex/syscalls.c:164 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f244ac67049 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f24495dc218 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: ffffffffffffffda RBX: 00007f244ad79f68 RCX: 00007f244ac67049 RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007f244ad79f6c RBP: 00007f244ad79f60 R08: 00007ffe359f9080 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f244ad79f6c R13: 00007ffe3598043f R14: 00007f24495dc300 R15: 0000000000022000 rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g470441 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=1 timer-softirq=157239 rcu: rcu_preempt kthread starved for 10502 jiffies! g470441 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=1 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:28664 pid: 14 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:4995 [inline] __schedule+0xa94/0x4910 kernel/sched/core.c:6304 schedule+0xd2/0x260 kernel/sched/core.c:6377 schedule_timeout+0x14a/0x2a0 kernel/time/timer.c:1881 rcu_gp_fqs_loop+0x186/0x810 kernel/rcu/tree.c:1963 rcu_gp_kthread+0x1de/0x320 kernel/rcu/tree.c:2136 kthread+0x2e9/0x3a0 kernel/kthread.c:377 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 30493 Comm: syz-executor.4 Not tainted 5.17.0-rc8-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:arch_atomic_read arch/x86/include/asm/atomic.h:29 [inline] RIP: 0010:rcu_dynticks_curr_cpu_in_eqs kernel/rcu/tree.c:330 [inline] RIP: 0010:rcu_is_watching+0x58/0xb0 kernel/rcu/tree.c:1128 Code: 48 89 fa 48 c1 ea 03 80 3c 02 00 75 51 48 03 1c ed a0 e8 58 8b 48 b8 00 00 00 00 00 fc ff df 48 89 da 48 c1 ea 03 0f b6 14 02 <48> 89 d8 83 e0 07 83 c0 03 38 d0 7c 04 84 d2 75 19 8b 03 83 e0 01 RSP: 0018:ffffc90000dc0d18 EFLAGS: 00000012 RAX: dffffc0000000000 RBX: ffff8880b9d3ac50 RCX: ffffffff815d9338 RDX: 0000000000000000 RSI: 0000000000010005 RDI: ffffffff8b58e8a8 RBP: 0000000000000001 R08: 0000000000000000 R09: ffffffff8d943057 R10: fffffbfff1b2860a R11: 0000000000000000 R12: 0000000000000001 R13: 0000000000000000 R14: ffff8880b9d2a618 R15: 0000000000000000 FS: 00007f24495dc700(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f244ad7a028 CR3: 00000000486a6000 CR4: 0000000000350ee0 Call Trace: rcu_read_lock_held_common kernel/rcu/update.c:108 [inline] rcu_read_lock_sched_held+0x1c/0x70 kernel/rcu/update.c:123 trace_lock_acquire include/trace/events/lock.h:13 [inline] lock_acquire+0x442/0x510 kernel/locking/lockdep.c:5610 __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:638 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 ea 81 0e f8 48 89 ef e8 42 00 0f f8 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 f3 b7 01 f8 65 8b 05 1c 66 b3 76 85 c0 74 0a 5b 5d c3 e8 30 f4 RSP: 0018:ffffc900049dfb98 EFLAGS: 00000206 RAX: 0000000000000006 RBX: 0000000000000200 RCX: 1ffffffff1b28099 RDX: 0000000000000000 RSI: 0000000000000002 RDI: 0000000000000001 RBP: ffff888047d04380 R08: 0000000000000001 R09: 0000000000000001 R10: ffffffff817efe18 R11: 0000000000000000 R12: 0000000000000206 R13: ffff888047d03a14 R14: ffff888047d04380 R15: ffff8880b9c39c40 try_to_wake_up+0x560/0x1510 kernel/sched/core.c:4135 wake_up_process kernel/sched/core.c:4217 [inline] wake_up_q+0x7e/0xf0 kernel/sched/core.c:964 futex_wake+0x3e9/0x490 kernel/futex/waitwake.c:184 do_futex+0x266/0x300 kernel/futex/syscalls.c:111 __do_sys_futex kernel/futex/syscalls.c:183 [inline] __se_sys_futex kernel/futex/syscalls.c:164 [inline] __x64_sys_futex+0x1b0/0x4a0 kernel/futex/syscalls.c:164 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f244ac67049 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f24495dc218 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: ffffffffffffffda RBX: 00007f244ad79f68 RCX: 00007f244ac67049 RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007f244ad79f6c RBP: 00007f244ad79f60 R08: 00007ffe359f9080 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f244ad79f6c R13: 00007ffe3598043f R14: 00007f24495dc300 R15: 0000000000022000 ---------------- Code disassembly (best guess): 0: 48 89 fa mov %rdi,%rdx 3: 48 c1 ea 03 shr $0x3,%rdx 7: 80 3c 02 00 cmpb $0x0,(%rdx,%rax,1) b: 75 7b jne 0x88 d: 48 8d 7d 70 lea 0x70(%rbp),%rdi 11: 48 8b 5b 20 mov 0x20(%rbx),%rbx 15: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 1c: fc ff df 1f: 48 89 fa mov %rdi,%rdx 22: 48 c1 ea 03 shr $0x3,%rdx 26: 80 3c 02 00 cmpb $0x0,(%rdx,%rax,1) * 2a: 75 66 jne 0x92 <-- trapping instruction 2c: 48 8b 45 70 mov 0x70(%rbp),%rax 30: 48 85 c3 test %rax,%rbx 33: 74 11 je 0x46 35: b8 01 00 00 00 mov $0x1,%eax 3a: 65 gs 3b: ff .byte 0xff 3c: 0d .byte 0xd 3d: 44 rex.R 3e: 46 9e rex.RX sahf