INFO: rcu detected stall in nsim_fib_event

Kernel	Title	Repro	Cause bisect	Fix bisect	Count	Last	Reported	Patched	Status
linux-5.15	INFO: rcu detected stall in nsim_fib_event_work origin:upstream missing-backport	syz		error	2	63d	81d	0/3	upstream: reported syz repro on 2024/09/01 09:18
linux-6.1	INFO: rcu detected stall in nsim_fib_event_work (2)				1	45d	45d	0/3	upstream: reported on 2024/10/06 20:10
rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	1-...!: (1 GPs behind) idle=5d0c/1/0x4000000000000000 softirq=8935/8936 fqs=1
	(t=10501 jiffies g=8493 q=140 ncpus=2)
rcu: rcu_preempt kthread starved for 10498 jiffies! g8493 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->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:R  running task     stack:25816 pid:16    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5245 [inline]
 __schedule+0x142d/0x4550 kernel/sched/core.c:6558
 schedule+0xbf/0x180 kernel/sched/core.c:6634
 schedule_timeout+0x1b9/0x300 kernel/time/timer.c:1965
 rcu_gp_fqs_loop+0x2d2/0x1150 kernel/rcu/tree.c:1706
 rcu_gp_kthread+0xa3/0x3b0 kernel/rcu/tree.c:1905
 kthread+0x28d/0x320 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308
 </TASK>
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: 3939 Comm: syz-executor.2 Not tainted 6.1.92-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
RIP: 0010:check_preemption_disabled+0x2/0x110 lib/smp_processor_id.c:13
Code: 1c 8d 48 89 de e8 8e 67 d8 f9 e9 6d ff ff ff cc cc cc cc cc cc cc cc cc 48 c7 c7 80 45 3d 8b 48 c7 c6 c0 45 3d 8b eb 00 41 57 <41> 56 41 54 53 48 83 ec 10 65 48 8b 04 25 28 00 00 00 48 89 44 24
RSP: 0018:ffffc9000382f770 EFLAGS: 00000046
RAX: 0000000000000000 RBX: 1ffff11004e167f7 RCX: ffffffff81735b3b
RDX: 0000000000000000 RSI: ffffffff8aed4840 RDI: ffffffff8b3d45e0
RBP: ffffc9000382f8f0 R08: dffffc0000000000 R09: fffffbfff1ce712e
R10: 0000000000000000 R11: dffffc0000000001 R12: ffff8880270b3b80
R13: 0000000000000000 R14: 1ffff92000705f0c R15: ffff8880270b3fbc
FS:  00007ff8f27d56c0(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000056123f37b030 CR3: 000000001e835000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <TASK>
 rcu_preempt_need_deferred_qs kernel/rcu/tree_plugin.h:588 [inline]
 rcu_preempt_deferred_qs kernel/rcu/tree_plugin.h:604 [inline]
 rcu_note_context_switch+0x1a5/0xf30 kernel/rcu/tree_plugin.h:344
 __schedule+0x32e/0x4550 kernel/sched/core.c:6458
 schedule+0xbf/0x180 kernel/sched/core.c:6634
 futex_wait_queue+0x149/0x1d0 kernel/futex/waitwake.c:355
 futex_wait+0x203/0x5c0 kernel/futex/waitwake.c:656
 do_futex+0x3b5/0x490 kernel/futex/syscalls.c:106
 __do_sys_futex kernel/futex/syscalls.c:183 [inline]
 __se_sys_futex+0x3d7/0x460 kernel/futex/syscalls.c:164
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7ff8f3c7cf69
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 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 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ff8f27d5178 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: ffffffffffffffda RBX: 00007ff8f3db4058 RCX: 00007ff8f3c7cf69
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007ff8f3db4058
RBP: 00007ff8f3db4050 R08: 00007ff8f27d56c0 R09: 00007ff8f27d56c0
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ff8f3db405c
R13: 000000000000006e R14: 00007fffacc00040 R15: 00007fffacc00128
 </TASK>
CPU: 1 PID: 3611 Comm: kworker/1:5 Not tainted 6.1.92-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
Workqueue: events nsim_fib_event_work
RIP: 0010:finish_task_switch+0x1d3/0x810 kernel/sched/core.c:5124
Code: 37 0b 00 48 83 c4 08 4c 89 f7 e8 98 30 00 00 e9 8f 04 00 00 4c 89 f7 e8 7b 20 36 09 e8 36 26 32 00 fb 49 8d bc 24 f8 15 00 00 <48> 89 f8 48 c1 e8 03 49 bd 00 00 00 00 00 fc ff df 42 0f b6 04 28
RSP: 0018:ffffc900042cf268 EFLAGS: 00000286
RAX: 4461e94d44670300 RBX: ffff8880b993b748 RCX: ffffffff816acf0a
RDX: dffffc0000000000 RSI: ffffffff8aec01c0 RDI: ffff88802463b3b8
RBP: ffffc900042cf2b0 R08: dffffc0000000000 R09: fffffbfff2093860
R10: 0000000000000000 R11: dffffc0000000001 R12: ffff888024639dc0
R13: 1ffff110173276eb R14: ffff8880b983aa00 R15: ffff8880b993b758
FS:  0000000000000000(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 000000001e835000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 </IRQ>
 <TASK>
 context_switch kernel/sched/core.c:5248 [inline]
 __schedule+0x1435/0x4550 kernel/sched/core.c:6558
 preempt_schedule_irq+0xf7/0x1c0 kernel/sched/core.c:6870
 irqentry_exit+0x53/0x80 kernel/entry/common.c:439
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:653
RIP: 0010:__preempt_count_add arch/x86/include/asm/preempt.h:80 [inline]
RIP: 0010:preempt_count_add+0x39/0x180 kernel/sched/core.c:5706
Code: c1 e8 03 49 bf 00 00 00 00 00 fc ff df 42 0f b6 04 38 84 c0 0f 85 e2 00 00 00 83 3d e0 ee 6a 10 00 75 07 65 8b 05 bf 1c a4 7e <65> 01 1d b8 1c a4 7e 48 c7 c0 60 41 c9 91 48 c1 e8 03 42 0f b6 04
RSP: 0018:ffffc900042cf5f8 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffffffff91c94103
RDX: 0000000000000000 RSI: 0000000000000008 RDI: 0000000000000001
RBP: ffffc900042cf738 R08: dffffc0000000000 R09: ffffed10048c73b9
R10: 0000000000000000 R11: dffffc0000000001 R12: ffff888024639dc0
R13: 1ffff92000859ec8 R14: ffff88802463b038 R15: dffffc0000000000
 schedule+0xb8/0x180 kernel/sched/core.c:6633
 schedule_timeout+0x1b9/0x300 kernel/time/timer.c:1965
 schedule_timeout_uninterruptible kernel/time/timer.c:1999 [inline]
 msleep+0x9d/0xe0 kernel/time/timer.c:2121
 nsim_fib6_rt_add drivers/net/netdevsim/fib.c:693 [inline]
 nsim_fib6_rt_insert drivers/net/netdevsim/fib.c:759 [inline]
 nsim_fib6_event drivers/net/netdevsim/fib.c:856 [inline]
 nsim_fib_event drivers/net/netdevsim/fib.c:889 [inline]
 nsim_fib_event_work+0x2e28/0x4120 drivers/net/netdevsim/fib.c:1492
 process_one_work+0x8a9/0x11d0 kernel/workqueue.c:2292
 worker_thread+0xa47/0x1200 kernel/workqueue.c:2439
 kthread+0x28d/0x320 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308
 </TASK>