rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	0-...!: (0 ticks this GP) idle=48b/1/0x4000000000000002 softirq=7112/7112 fqs=0 
	(detected by 1, t=10506 jiffies, g=7121, q=614)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 4402 Comm: syz.0.50 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:lock_is_held_type+0x4c/0x190 kernel/locking/lockdep.c:5659
Code: 3d 6c 7f c7 03 00 0f 84 03 01 00 00 65 8b 05 5b 8f 60 76 85 c0 0f 85 f4 00 00 00 65 48 8b 1d cb 85 60 76 83 bb ec 0a 00 00 00 <0f> 85 df 00 00 00 41 89 f7 49 89 fe 48 c7 04 24 00 00 00 00 9c 8f
RSP: 0000:ffffc900035cf1f0 EFLAGS: 00000046
RAX: 0000000000000000 RBX: ffff888023ea3b80 RCX: 6b6339de1f3c9500
RDX: 0000000000000000 RSI: 00000000ffffffff RDI: ffffffff8c11c720
RBP: 00000000ffffffff R08: dffffc0000000000 R09: ffffc900035cf3a0
R10: fffff520006b9e7b R11: 1ffff920006b9e74 R12: dffffc0000000000
R13: ffffc900035cf406 R14: ffffffff8bf23a40 R15: dffffc0000000000
FS:  000055558ab6b500(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f0508407000 CR3: 0000000071832000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 perf_get_guest_cbs include/linux/perf_event.h:1274 [inline]
 perf_misc_flags+0x56/0x1b0 arch/x86/events/core.c:2961
 perf_prepare_sample+0x132/0x1cb0 kernel/events/core.c:7622
 __perf_event_output kernel/events/core.c:7802 [inline]
 perf_event_output_forward+0x146/0x280 kernel/events/core.c:7822
 __perf_event_overflow+0x364/0x530 kernel/events/core.c:9515
 perf_swevent_overflow kernel/events/core.c:9591 [inline]
 perf_swevent_event+0x4ad/0x530 kernel/events/core.c:9629
 perf_tp_event+0x32c/0xb50 kernel/events/core.c:10047
 perf_trace_run_bpf_submit+0xf3/0x1c0 kernel/events/core.c:10021
 perf_trace_preemptirq_template+0x2be/0x380 include/trace/events/preemptirq.h:14
 trace_irq_enable_rcuidle+0x108/0x180 include/trace/events/preemptirq.h:40
 trace_hardirqs_on+0x57/0x80 kernel/trace/trace_preemptirq.c:44
 asm_sysvec_irq_work+0x16/0x20 arch/x86/include/asm/idtentry.h:713
RIP: 0010:rcu_read_unlock_special+0x84/0x480 kernel/rcu/tree_plugin.h:674
Code: f1 f1 f1 00 f2 f2 f2 4a 89 04 2b 66 42 c7 44 2b 09 f3 f3 42 c6 44 2b 0b f3 65 44 8b 35 ed 11 9e 7e 41 f7 c6 00 00 f0 00 74 45 <48> c7 44 24 20 0e 36 e0 45 4a c7 04 2b 00 00 00 00 66 42 c7 44 2b
RSP: 0000:ffffc900035cfa00 EFLAGS: 00000206
RAX: 6b6339de1f3c9500 RBX: 1ffff920006b9f44 RCX: 6b6339de1f3c9500
RDX: dffffc0000000000 RSI: ffffffff8a0b1be0 RDI: ffffffff8a59e800
RBP: ffffc900035cfad0 R08: dffffc0000000000 R09: fffffbfff1ff5419
R10: fffffbfff1ff5419 R11: 1ffffffff1ff5418 R12: ffffffff8c120c00
R13: dffffc0000000000 R14: 0000000000000246 R15: 0000000000000001
 __rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:422
 rcu_read_unlock include/linux/rcupdate.h:772 [inline]
 __unlock_page_memcg+0xea/0x100 mm/memcontrol.c:2093
 wp_page_copy+0xeb2/0x1fd0 mm/memory.c:3148
 handle_pte_fault mm/memory.c:4668 [inline]
 __handle_mm_fault mm/memory.c:4785 [inline]
 handle_mm_fault+0x1ec7/0x43b0 mm/memory.c:4883
 do_user_addr_fault+0x489/0xc80 arch/x86/mm/fault.c:1357
 handle_page_fault arch/x86/mm/fault.c:1445 [inline]
 exc_page_fault+0x60/0x100 arch/x86/mm/fault.c:1501
 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:606
RIP: 0033:0x7f05080862e8
Code: 80 3d 3b 0d 38 00 00 89 7c 24 0c 88 54 24 10 48 89 74 24 28 0f 85 c8 09 00 00 80 3d 06 44 eb 00 00 48 89 f5 41 89 d4 41 89 cd <c6> 05 11 0d 38 00 01 0f 85 23 04 00 00 80 3d d4 43 eb 00 00 0f 85
RSP: 002b:00007ffc7175db30 EFLAGS: 00010246
RAX: 00007f050840afa0 RBX: 00007f050840afa8 RCX: 0000000000000000
RDX: 00000000fffffc03 RSI: 00007f050840b038 RDI: 0000000000000000
RBP: 00007f050840b038 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: 00000000fffffc03
R13: 0000000000000000 R14: 00007ffc7175dba8 R15: 0000000000000005
 </TASK>
rcu: rcu_preempt kthread timer wakeup didn't happen for 10505 jiffies! g7121 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: 	Possible timer handling issue on cpu=0 timer-softirq=2685
rcu: rcu_preempt kthread starved for 10506 jiffies! g7121 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:27904 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 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 4402 Comm: syz.0.50 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:hlock_class kernel/locking/lockdep.c:192 [inline]
RIP: 0010:__lock_acquire+0x12ad/0x7c60 kernel/locking/lockdep.c:5009
Code: 00 00 74 12 48 89 df e8 01 23 60 00 49 b8 00 00 00 00 00 fc ff df 48 83 3b 00 0f 84 10 4b 00 00 48 8b 44 24 58 42 0f b6 04 00 <84> c0 0f 85 16 5a 00 00 41 8b 07 89 c3 81 e3 ff 1f 00 00 c1 e8 03
RSP: 0000:ffffc900035cee60 EFLAGS: 00000086
RAX: 0000000000000000 RBX: ffffffff8f932f80 RCX: ffffffff815c0fcf
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff8ffaa0c0
RBP: ffffc900035cf0b0 R08: dffffc0000000000 R09: fffffbfff1ff5419
R10: fffffbfff1ff5419 R11: 1ffffffff1ff5418 R12: 000000000466878f
R13: ffff888023ea3b80 R14: 00000000044ba132 R15: ffff888023ea4730
FS:  000055558ab6b500(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f0508407000 CR3: 0000000071832000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 lock_acquire+0x197/0x3f0 kernel/locking/lockdep.c:5623
 rcu_lock_acquire+0x2a/0x30 include/linux/rcupdate.h:313
 rcu_read_lock include/linux/rcupdate.h:740 [inline]
 __perf_output_begin kernel/events/ring_buffer.c:163 [inline]
 perf_output_begin_forward+0x97/0xa30 kernel/events/ring_buffer.c:271
 __perf_event_output kernel/events/core.c:7804 [inline]
 perf_event_output_forward+0x15c/0x280 kernel/events/core.c:7822
 __perf_event_overflow+0x364/0x530 kernel/events/core.c:9515
 perf_swevent_overflow kernel/events/core.c:9591 [inline]
 perf_swevent_event+0x4ad/0x530 kernel/events/core.c:9629
 perf_tp_event+0x32c/0xb50 kernel/events/core.c:10047
 perf_trace_run_bpf_submit+0xf3/0x1c0 kernel/events/core.c:10021
 perf_trace_preemptirq_template+0x2be/0x380 include/trace/events/preemptirq.h:14
 trace_irq_enable_rcuidle+0x108/0x180 include/trace/events/preemptirq.h:40
 trace_hardirqs_on+0x57/0x80 kernel/trace/trace_preemptirq.c:44
 asm_sysvec_irq_work+0x16/0x20 arch/x86/include/asm/idtentry.h:713
RIP: 0010:rcu_read_unlock_special+0x84/0x480 kernel/rcu/tree_plugin.h:674
Code: f1 f1 f1 00 f2 f2 f2 4a 89 04 2b 66 42 c7 44 2b 09 f3 f3 42 c6 44 2b 0b f3 65 44 8b 35 ed 11 9e 7e 41 f7 c6 00 00 f0 00 74 45 <48> c7 44 24 20 0e 36 e0 45 4a c7 04 2b 00 00 00 00 66 42 c7 44 2b
RSP: 0000:ffffc900035cfa00 EFLAGS: 00000206
RAX: 6b6339de1f3c9500 RBX: 1ffff920006b9f44 RCX: 6b6339de1f3c9500
RDX: dffffc0000000000 RSI: ffffffff8a0b1be0 RDI: ffffffff8a59e800
RBP: ffffc900035cfad0 R08: dffffc0000000000 R09: fffffbfff1ff5419
R10: fffffbfff1ff5419 R11: 1ffffffff1ff5418 R12: ffffffff8c120c00
R13: dffffc0000000000 R14: 0000000000000246 R15: 0000000000000001
 __rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:422
 rcu_read_unlock include/linux/rcupdate.h:772 [inline]
 __unlock_page_memcg+0xea/0x100 mm/memcontrol.c:2093
 wp_page_copy+0xeb2/0x1fd0 mm/memory.c:3148
 handle_pte_fault mm/memory.c:4668 [inline]
 __handle_mm_fault mm/memory.c:4785 [inline]
 handle_mm_fault+0x1ec7/0x43b0 mm/memory.c:4883
 do_user_addr_fault+0x489/0xc80 arch/x86/mm/fault.c:1357
 handle_page_fault arch/x86/mm/fault.c:1445 [inline]
 exc_page_fault+0x60/0x100 arch/x86/mm/fault.c:1501
 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:606
RIP: 0033:0x7f05080862e8
Code: 80 3d 3b 0d 38 00 00 89 7c 24 0c 88 54 24 10 48 89 74 24 28 0f 85 c8 09 00 00 80 3d 06 44 eb 00 00 48 89 f5 41 89 d4 41 89 cd <c6> 05 11 0d 38 00 01 0f 85 23 04 00 00 80 3d d4 43 eb 00 00 0f 85
RSP: 002b:00007ffc7175db30 EFLAGS: 00010246
RAX: 00007f050840afa0 RBX: 00007f050840afa8 RCX: 0000000000000000
RDX: 00000000fffffc03 RSI: 00007f050840b038 RDI: 0000000000000000
RBP: 00007f050840b038 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: 00000000fffffc03
R13: 0000000000000000 R14: 00007ffc7175dba8 R15: 0000000000000005
 </TASK>