rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P4300/1:b..l P13357/1:b..l
	(detected by 0, t=10502 jiffies, g=64785, q=21)
task:kworker/u4:17   state:R  running task     stack:23552 pid:13357 ppid:     2 flags:0x00004000
Workqueue: writeback wb_workfn (flush-7:7)
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5049 [inline]
 __schedule+0x11bb/0x4390 kernel/sched/core.c:6395
 preempt_schedule_common+0x82/0xd0 kernel/sched/core.c:6571
 preempt_schedule+0xa7/0xb0 kernel/sched/core.c:6596
 preempt_schedule_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:34
 __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:169 [inline]
 _raw_spin_unlock_irq+0x3c/0x40 kernel/locking/spinlock.c:202
 spin_unlock_irq include/linux/spinlock.h:414 [inline]
 loop_queue_work drivers/block/loop.c:1069 [inline]
 loop_queue_rq+0x9e0/0xac0 drivers/block/loop.c:2202
 __blk_mq_issue_directly block/blk-mq.c:2014 [inline]
 __blk_mq_try_issue_directly+0x497/0x810 block/blk-mq.c:2070
 blk_mq_request_issue_directly block/blk-mq.c:2118 [inline]
 blk_mq_try_issue_list_directly+0x1a1/0x530 block/blk-mq.c:2136
 blk_mq_sched_insert_requests+0x2d6/0x5c0 block/blk-mq-sched.c:512
 blk_mq_flush_plug_list+0x57f/0x660 block/blk-mq.c:1971
 blk_flush_plug_list+0x3ec/0x430 block/blk-core.c:1734
 blk_finish_plug+0x59/0x80 block/blk-core.c:1751
 wb_writeback+0xb14/0xb90 fs/fs-writeback.c:2148
 wb_do_writeback fs/fs-writeback.c:2257 [inline]
 wb_workfn+0x423/0xe60 fs/fs-writeback.c:2298
 process_one_work+0x863/0x1000 kernel/workqueue.c:2310
 worker_thread+0xaa8/0x12a0 kernel/workqueue.c:2457
 kthread+0x436/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
task:kworker/1:7     state:R  running task     stack:23752 pid: 4300 ppid:     2 flags:0x00004000
Workqueue: events_power_efficient gc_worker
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5049 [inline]
 __schedule+0x11bb/0x4390 kernel/sched/core.c:6395
 preempt_schedule_irq+0xb1/0x150 kernel/sched/core.c:6799
 irqentry_exit+0x63/0x70 kernel/entry/common.c:432
 asm_sysvec_reschedule_ipi+0x16/0x20 arch/x86/include/asm/idtentry.h:681
RIP: 0010:seqcount_lockdep_reader_access+0x17b/0x1c0 include/linux/seqlock.h:106
Code: f9 4d 85 e4 75 16 e8 84 38 61 f9 eb 15 e8 7d 38 61 f9 e8 48 da 92 01 4d 85 e4 74 ea e8 6e 38 61 f9 fb 48 c7 04 24 0e 36 e0 45 <4b> c7 04 3e 00 00 00 00 66 43 c7 44 3e 09 00 00 43 c6 44 3e 0b 00
RSP: 0018:ffffc9000348fa20 EFLAGS: 00000293
RAX: ffffffff881693a2 RBX: 0000000000000000 RCX: ffff88801dc59dc0
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc9000348fad0 R08: dffffc0000000000 R09: fffffbfff1ff7c2c
R10: fffffbfff1ff7c2c R11: 1ffffffff1ff7c2b R12: 0000000000000200
R13: ffff888073b78318 R14: 1ffff92000691f44 R15: dffffc0000000000
 nf_conntrack_get_ht include/net/netfilter/nf_conntrack.h:338 [inline]
 gc_worker+0x2e2/0x13a0 net/netfilter/nf_conntrack_core.c:1472
 process_one_work+0x863/0x1000 kernel/workqueue.c:2310
 worker_thread+0xaa8/0x12a0 kernel/workqueue.c:2457
 kthread+0x436/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
rcu: rcu_preempt kthread starved for 10558 jiffies! g64785 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:28128 pid:   15 ppid:     2 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5049 [inline]
 __schedule+0x11bb/0x4390 kernel/sched/core.c:6395
 schedule+0x11b/0x1e0 kernel/sched/core.c:6478
 schedule_timeout+0x15c/0x280 kernel/time/timer.c:1914
 rcu_gp_fqs_loop+0x29e/0x11b0 kernel/rcu/tree.c:1972
 rcu_gp_kthread+0x98/0x350 kernel/rcu/tree.c:2145
 kthread+0x436/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </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: 15283 Comm: syz.0.2450 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
RIP: 0010:irq_exit_rcu+0x0/0x20 kernel/softirq.c:671
Code: 89 d9 80 e1 07 80 c1 03 38 c1 7c 81 48 89 df e8 86 b5 73 00 e9 74 ff ff ff 90 e8 5b f9 60 08 e9 16 ff ff ff 66 0f 1f 44 00 00 <e8> 1b 00 00 00 48 c7 c7 c0 04 0a 8a e8 cf ff 60 08 65 ff 0d 3c f7
RSP: 0018:ffffc90000dd0ff0 EFLAGS: 00000086
RAX: 0000000000000001 RBX: ffffc900030dfb18 RCX: 19291d3b7e599700
RDX: 0000000000000000 RSI: ffffffff8a07f620 RDI: ffffffff8a59e580
RBP: 0000000000000000 R08: dffffc0000000000 R09: fffffbfff1ad33a6
R10: fffffbfff1ad33a6 R11: 1ffffffff1ad33a5 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
FS:  00007f21318126c0(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000020000006b000 CR3: 0000000062773000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
 sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1108
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:169 [inline]
RIP: 0010:_raw_spin_unlock_irq+0x25/0x40 kernel/locking/spinlock.c:202
Code: f6 ff 0f 1f 00 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 de 9e a9 f7 48 89 df e8 a6 73 aa f7 e8 41 0d cb f7 fb bf 01 00 00 00 <e8> 76 95 9e f7 65 8b 05 07 93 4f 76 85 c0 74 02 5b c3 e8 b4 9d 4d
RSP: 0018:ffffc900030dfbc0 EFLAGS: 00000282
RAX: 19291d3b7e599700 RBX: ffff88801abdae40 RCX: 19291d3b7e599700
RDX: dffffc0000000000 RSI: ffffffff8a0b1c60 RDI: 0000000000000001
RBP: 0000000000000000 R08: dffffc0000000000 R09: ffffed100357b5c9
R10: ffffed100357b5c9 R11: 1ffff1100357b5c8 R12: ffff88801abdae40
R13: 0000000000000021 R14: dffffc0000000000 R15: 000000001c000004
 spin_unlock_irq include/linux/spinlock.h:414 [inline]
 get_signal+0x11d6/0x12c0 kernel/signal.c:2903
 arch_do_signal_or_restart+0xc1/0x1300 arch/x86/kernel/signal.c:867
 handle_signal_work kernel/entry/common.c:154 [inline]
 exit_to_user_mode_loop+0x9e/0x130 kernel/entry/common.c:178
 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:214
 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline]
 syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307
 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f21335ab6c7
Code: ff ff 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 a8 ff ff ff f7 d8 64 89
RSP: 002b:00007f21318120e8 EFLAGS: 00000246
RAX: 00000000000000ca RBX: 00007f2133801fa8 RCX: 00007f21335ab6c9
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f2133801fa8
RBP: 00007f2133801fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f2133802038 R14: 00007ffd4f580810 R15: 00007ffd4f5808f8
 </TASK>