INFO: rcu detected stall in sys

Kernel	Title	Repro	Cause bisect	Count	Last	Reported	Patched	Status
upstream	INFO: rcu detected stall in sys_unshare (5) net			1	822d	822d	0/26	closed as invalid on 2022/02/08 10:10
upstream	INFO: rcu detected stall in sys_unshare (3) net			1	1046d	1046d	0/26	auto-closed as invalid on 2021/09/03 04:28
upstream	INFO: rcu detected stall in sys_unshare (6) kernfs			1	792d	792d	0/26	auto-closed as invalid on 2022/05/15 15:21
upstream	INFO: rcu detected stall in sys_unshare (9) bpf	C	inconclusive	3	43d	157d	0/26	upstream: reported C repro on 2023/11/11 00:17
upstream	INFO: rcu detected stall in sys_unshare kernel			3	1595d	1596d	0/26	closed as invalid on 2019/12/04 14:04
upstream	INFO: rcu detected stall in sys_unshare (4) kernel			1	955d	955d	0/26	auto-closed as invalid on 2021/12/03 09:38
upstream	INFO: rcu detected stall in sys_unshare (7) bpf net			12	408d	539d	0/26	auto-obsoleted due to no activity on 2023/06/03 15:22
linux-6.1	INFO: rcu detected stall in sys_unshare origin:upstream	C		1	30d	134d	0/3	upstream: reported C repro on 2023/12/04 08:29

rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 1-...!: (10499 ticks this GP) idle=6aa/1/0x4000000000000002 softirq=12532/12532 fqs=2 (t=10500 jiffies g=7013 q=54) rcu: rcu_preempt kthread starved for 10496 jiffies! g7013 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0 rcu: RCU grace-period kthread stack dump: rcu_preempt R running task 29032 10 2 0x80004000 Call Trace: context_switch kernel/sched/core.c:3385 [inline] __schedule+0x9a0/0xcc0 kernel/sched/core.c:4081 schedule+0x181/0x210 kernel/sched/core.c:4155 schedule_timeout+0x14f/0x240 kernel/time/timer.c:1895 rcu_gp_fqs_loop kernel/rcu/tree.c:1661 [inline] rcu_gp_kthread+0xed8/0x1770 kernel/rcu/tree.c:1821 kthread+0x332/0x350 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 NMI backtrace for cpu 1 CPU: 1 PID: 8596 Comm: syz-executor.0 Not tainted 5.5.0-rc5-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: <IRQ> __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1fb/0x318 lib/dump_stack.c:118 nmi_cpu_backtrace+0xaf/0x1a0 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x174/0x290 lib/nmi_backtrace.c:62 arch_trigger_cpumask_backtrace+0x10/0x20 arch/x86/kernel/apic/hw_nmi.c:38 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline] rcu_dump_cpu_stacks+0x15a/0x220 kernel/rcu/tree_stall.h:254 print_cpu_stall kernel/rcu/tree_stall.h:455 [inline] check_cpu_stall kernel/rcu/tree_stall.h:529 [inline] rcu_pending kernel/rcu/tree.c:2827 [inline] rcu_sched_clock_irq+0xe25/0x1ad0 kernel/rcu/tree.c:2271 update_process_times+0x12d/0x180 kernel/time/timer.c:1726 tick_sched_handle kernel/time/tick-sched.c:167 [inline] tick_sched_timer+0x263/0x420 kernel/time/tick-sched.c:1310 __run_hrtimer kernel/time/hrtimer.c:1517 [inline] __hrtimer_run_queues+0x403/0x840 kernel/time/hrtimer.c:1579 hrtimer_interrupt+0x38c/0xda0 kernel/time/hrtimer.c:1641 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1110 [inline] smp_apic_timer_interrupt+0x109/0x280 arch/x86/kernel/apic/apic.c:1135 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:829 </IRQ> RIP: 0010:__sanitizer_cov_trace_pc+0x35/0x50 kernel/kcov.c:193 Code: 02 00 65 8b 15 38 5f 8b 7e f7 c2 00 01 1f 00 75 2c 8b 91 80 13 00 00 83 fa 02 75 21 48 8b 91 88 13 00 00 48 8b 32 48 8d 7e 01 <8b> 89 84 13 00 00 48 39 cf 73 08 48 89 44 f2 08 48 89 3a c3 0f 1f RSP: 0018:ffffc900022d7990 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13 RAX: ffffffff814897d3 RBX: 0000000000000000 RCX: ffff888094550640 RDX: ffffc90001f99000 RSI: 000000000003ffff RDI: 0000000000040000 RBP: ffffc900022d79b8 R08: dffffc0000000000 R09: fffffbfff124248a R10: fffffbfff124248a R11: 0000000000000000 R12: dffffc0000000000 R13: dffffc0000000000 R14: 00000000fffffffc R15: ffff8880a88155f8 free_thread_stack+0x168/0x590 kernel/fork.c:280 release_task_stack kernel/fork.c:440 [inline] put_task_stack+0xa3/0x130 kernel/fork.c:451 finish_task_switch+0x3f1/0x550 kernel/sched/core.c:3256 context_switch kernel/sched/core.c:3388 [inline] __schedule+0x9a8/0xcc0 kernel/sched/core.c:4081 preempt_schedule_common kernel/sched/core.c:4236 [inline] preempt_schedule+0xdb/0x120 kernel/sched/core.c:4261 ___preempt_schedule+0x16/0x18 arch/x86/entry/thunk_64.S:50 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:161 [inline] _raw_spin_unlock_irqrestore+0xcc/0xe0 kernel/locking/spinlock.c:191 spin_unlock_irqrestore include/linux/spinlock.h:393 [inline] prepare_to_wait_event+0x3c6/0x500 kernel/sched/wait.c:305 synchronize_rcu_expedited+0x46c/0x5a0 kernel/rcu/tree_exp.h:833 namespace_unlock+0x1f7/0x410 fs/namespace.c:1375 drop_collected_mounts fs/namespace.c:1858 [inline] put_mnt_ns+0xdf/0x200 fs/namespace.c:3778 free_nsproxy+0x4e/0x290 kernel/nsproxy.c:172 switch_task_namespaces+0xce/0xe0 kernel/nsproxy.c:225 ksys_unshare+0x6a0/0xa00 kernel/fork.c:2954 __do_sys_unshare kernel/fork.c:3003 [inline] __se_sys_unshare kernel/fork.c:3001 [inline] __x64_sys_unshare+0x38/0x40 kernel/fork.c:3001 do_syscall_64+0xf7/0x1c0 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45af49 Code: ad b6 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 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fabeb2dcc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000110 RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 000000000045af49 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000020400 RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fabeb2dd6d4 R13: 00000000004cc492 R14: 00000000004e7350 R15: 00000000ffffffff