INFO: rcu detected stall in nsim_fib_event

Kernel	Title	Repro	Cause bisect	Fix bisect	Count	Last	Reported	Patched	Status
linux-6.1	INFO: rcu detected stall in nsim_fib_event_work				1	163d	163d	0/3	auto-obsoleted due to no activity on 2024/09/19 04:15
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
rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	0-...!: (10499 ticks this GP) idle=862c/1/0x4000000000000000 softirq=10432/10432 fqs=1
	(t=10500 jiffies g=10305 q=73 ncpus=2)
rcu: rcu_preempt kthread starved for 10498 jiffies! g10305 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->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:R  running task     stack:25816 pid:16    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5241 [inline]
 __schedule+0x143f/0x4570 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:295
 </TASK>
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: 4439 Comm: syz.2.290 Not tainted 6.1.112-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
RIP: 0010:asm_sysvec_irq_work+0x0/0x20 arch/x86/include/asm/idtentry.h:675
Code: e9 b5 03 00 00 0f 1f 44 00 00 0f 01 ca fc 6a ff e8 b5 02 00 00 48 89 c4 48 89 e7 e8 aa 71 e6 ff e9 95 03 00 00 0f 1f 44 00 00 <0f> 01 ca fc 6a ff e8 95 02 00 00 48 89 c4 48 89 e7 e8 6a 76 e6 ff
RSP: 0018:ffffc9000363f878 EFLAGS: 00000086
RAX: 4759714da7e40d00 RBX: ffff88807a93bbb4 RCX: ffffffff97334103
RDX: dffffc0000000000 RSI: ffffffff8b0c0340 RDI: ffff888075f2ef38
RBP: ffffc9000363f8f0 R08: dffffc0000000000 R09: ffffed10171e7539
R10: 0000000000000000 R11: dffffc0000000001 R12: ffff888075f2d940
R13: 1ffff110171e76e3 R14: ffff8880b8f3a9c0 R15: ffff8880b8f3b718
FS:  00007fb543dfd6c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f8985192440 CR3: 0000000021732000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
RIP: 0010:finish_task_switch+0x1d3/0x810 kernel/sched/core.c:5120
Code: 32 0b 00 48 83 c4 08 4c 89 f7 e8 68 31 00 00 0f 1f 44 00 00 4c 89 f7 e8 9b bd 51 09 e8 26 21 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:ffffc9000363f8a8 EFLAGS: 00000286
 </TASK>
CPU: 0 PID: 3679 Comm: kworker/0:4 Not tainted 6.1.112-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Workqueue: events nsim_fib_event_work
RIP: 0010:finish_task_switch+0x1d3/0x810 kernel/sched/core.c:5120
Code: 32 0b 00 48 83 c4 08 4c 89 f7 e8 68 31 00 00 0f 1f 44 00 00 4c 89 f7 e8 9b bd 51 09 e8 26 21 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:ffffc9000439f288 EFLAGS: 00000282
RAX: 0e8fa73343cecc00 RBX: ffff8880761bbbb4 RCX: ffffffff816af0fa
RDX: dffffc0000000000 RSI: ffffffff8b0c0340 RDI: ffff88802d00d178
RBP: ffffc9000439f2d0 R08: dffffc0000000000 R09: fffffbfff223ba61
R10: 0000000000000000 R11: dffffc0000000001 R12: ffff88802d00bb80
R13: 1ffff110171c76e3 R14: ffff8880b8e3a9c0 R15: ffff8880b8e3b718
FS:  0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c452377 CR3: 0000000021732000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 </IRQ>
 <TASK>
 context_switch kernel/sched/core.c:5244 [inline]
 __schedule+0x1447/0x4570 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:schedule+0xae/0x180 kernel/sched/core.c:6633
Code: e8 f7 e3 32 f7 49 8b 3e 48 85 ff 74 0a be 01 00 00 00 e8 85 58 6d f9 4c 89 e3 48 c1 eb 03 eb 0a 49 f7 04 24 08 00 00 00 74 39 <bf> 01 00 00 00 e8 38 28 af f6 31 ff e8 d1 b9 ff ff bf 01 00 00 00
RSP: 0018:ffffc9000439f618 EFLAGS: 00000202
RAX: 0000000000000001 RBX: 1ffff11005a01770 RCX: ffffffff8aaf4dd6
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffff88802d00bb80
RBP: ffffc9000439f738 R08: dffffc0000000000 R09: ffffed1005a01771
R10: 0000000000000000 R11: dffffc0000000001 R12: ffff88802d00bb80
R13: 1ffff92000873ec8 R14: ffff88802d00cdf8 R15: dffffc0000000000
 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_fib4_rt_add drivers/net/netdevsim/fib.c:369 [inline]
 nsim_fib4_rt_insert drivers/net/netdevsim/fib.c:432 [inline]
 nsim_fib4_event drivers/net/netdevsim/fib.c:464 [inline]
 nsim_fib_event drivers/net/netdevsim/fib.c:884 [inline]
 nsim_fib_event_work+0x2139/0x4120 drivers/net/netdevsim/fib.c:1492
 process_one_work+0x8a9/0x11d0 kernel/workqueue.c:2292
 process_scheduled_works kernel/workqueue.c:2355 [inline]
 worker_thread+0xd04/0x1200 kernel/workqueue.c:2441
 kthread+0x28d/0x320 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>