rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P4252/1:b..l
	(detected by 0, t=10503 jiffies, g=7841, q=37 ncpus=2)
task:syz-executor920 state:R  running task     stack:25864 pid:4252  ppid:4247   flags:0x00004002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5244 [inline]
 __schedule+0x143f/0x4570 kernel/sched/core.c:6561
 preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:6730
 preempt_schedule+0xd9/0xe0 kernel/sched/core.c:6754
 preempt_schedule_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:34
 __raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline]
 _raw_spin_unlock+0x36/0x40 kernel/locking/spinlock.c:186
 spin_unlock include/linux/spinlock.h:391 [inline]
 filemap_map_pages+0xffa/0x12c0 mm/filemap.c:3498
 do_fault_around mm/memory.c:4600 [inline]
 do_read_fault mm/memory.c:4626 [inline]
 do_fault mm/memory.c:4760 [inline]
 handle_pte_fault mm/memory.c:5031 [inline]
 __handle_mm_fault mm/memory.c:5173 [inline]
 handle_mm_fault+0x33e0/0x5340 mm/memory.c:5294
 do_user_addr_fault arch/x86/mm/fault.c:1340 [inline]
 handle_page_fault arch/x86/mm/fault.c:1431 [inline]
 exc_page_fault+0x26f/0x620 arch/x86/mm/fault.c:1487
 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:608
RIP: 0033:0x7fc09c4a2c00
RSP: 002b:00007ffea8070988 EFLAGS: 00010246
RAX: 00007fc09c45c9d0 RBX: 00007fc09c45c6c0 RCX: 00007fc09c49bd07
RDX: 0000000000000003 RSI: 0000000000020000 RDI: 00007fc09c45c6c0
RBP: 0000000000000000 R08: 00000000ffffffff R09: 0000000000000000
R10: 0000000000021000 R11: 0000000000000206 R12: 00007ffea8070b60
R13: ffffffffffffffc0 R14: 0000000000001000 R15: 0000000000000000
 </TASK>
rcu: rcu_preempt kthread starved for 10519 jiffies! g7841 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:25592 pid:16    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5244 [inline]
 __schedule+0x143f/0x4570 kernel/sched/core.c:6561
 schedule+0xbf/0x180 kernel/sched/core.c:6637
 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: 4255 Comm: syz-executor920 Not tainted 6.1.132-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
RIP: 0010:rcu_preempt_read_exit kernel/rcu/tree_plugin.h:384 [inline]
RIP: 0010:__rcu_read_unlock+0x2f/0x100 kernel/rcu/tree_plugin.h:423
Code: 41 55 41 54 53 49 bc 00 00 00 00 00 fc ff df 65 4c 8b 35 54 0a 8e 7e 4d 8d ae 3c 04 00 00 4c 89 eb 48 c1 eb 03 42 0f b6 04 23 <84> c0 75 61 41 8b 6d 00 ff cd 42 0f b6 04 23 84 c0 75 69 41 89 6d
RSP: 0018:ffffc900001e0ba0 EFLAGS: 00000807
RAX: 0000000000000000 RBX: 1ffff110049d4baf RCX: ffff888024ea5940
RDX: 0000000000010000 RSI: ffffffff8b5f70c0 RDI: ffffffff8b5f7080
RBP: ffffc900001e0c80 R08: ffffffff81568232 R09: 0000000000000003
R10: ffffffffffffffff R11: dffffc0000000001 R12: dffffc0000000000
R13: ffff888024ea5d7c R14: ffff888024ea5940 R15: 1ffff9200003c190
FS:  00007fc09c45c6c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc09c45be40 CR3: 00000000729ed000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <IRQ>
 rcu_read_unlock include/linux/rcupdate.h:823 [inline]
 __lock_task_sighand+0x2a1/0x2d0 kernel/signal.c:1416
 lock_task_sighand include/linux/sched/signal.h:745 [inline]
 send_sigqueue+0x1de/0x720 kernel/signal.c:1979
 posix_timer_event kernel/time/posix-timers.c:359 [inline]
 posix_timer_fn+0x186/0x390 kernel/time/posix-timers.c:385
 __run_hrtimer kernel/time/hrtimer.c:1691 [inline]
 __hrtimer_run_queues+0x5e5/0xe50 kernel/time/hrtimer.c:1755
 hrtimer_interrupt+0x392/0x980 kernel/time/hrtimer.c:1817
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1107 [inline]
 __sysvec_apic_timer_interrupt+0x158/0x5b0 arch/x86/kernel/apic/apic.c:1124
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline]
 sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1118
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691
RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:160 [inline]
RIP: 0010:_raw_spin_unlock_irq+0x25/0x40 kernel/locking/spinlock.c:202
Code: f1 84 f5 ff 90 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 7e cb ae f6 48 89 df e8 e6 09 b0 f6 e8 a1 5b d5 f6 fb bf 01 00 00 00 <e8> f6 89 a2 f6 65 8b 05 b7 5f 46 75 85 c0 74 02 5b c3 e8 54 83 44
RSP: 0018:ffffc90003c67b30 EFLAGS: 00000286
RAX: df3dfad61937e100 RBX: ffff88802fa7d340 RCX: ffffffff973c2103
RDX: dffffc0000000000 RSI: ffffffff8b0c1dc0 RDI: 0000000000000001
RBP: ffffc90003c67c70 R08: dffffc0000000000 R09: ffffed1005f4fa69
R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff11005f4fafb
R13: 000000001c000004 R14: 0000000000000021 R15: ffff88802fa7d7d8
 spin_unlock_irq include/linux/spinlock.h:401 [inline]
 get_signal+0x151f/0x17a0 kernel/signal.c:2874
 arch_do_signal_or_restart+0xb0/0x1a10 arch/x86/kernel/signal.c:871
 exit_to_user_mode_loop+0x6a/0x100 kernel/entry/common.c:174
 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210
 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline]
 syscall_exit_to_user_mode+0x60/0x270 kernel/entry/common.c:303
 do_syscall_64+0x47/0xb0 arch/x86/entry/common.c:87
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fc09c49bc47
Code: 14 25 28 00 00 00 75 05 48 83 c4 28 c3 e8 81 18 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
RSP: 002b:00007fc09c45c218 EFLAGS: 00000246
RAX: 00000000000000ca RBX: 00007fc09c5263c8 RCX: 00007fc09c49bc49
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fc09c5263c8
RBP: 00007fc09c5263c0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000200000000140
R13: 000020000006b000 R14: 0000200000000100 R15: 0000200000000680
 </TASK>
INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.599 msecs