rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	0-...!: (1 GPs behind) idle=1a4c/1/0x4000000000000000 softirq=54272/54273 fqs=53
rcu: 	(detected by 1, t=10505 jiffies, g=60537, q=1809 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 12864 Comm: syz.5.2162 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
RIP: 0010:__kasan_check_read+0xa/0x20 mm/kasan/shadow.c:31
Code: 48 c7 c7 eb 3f 79 8c 4c 89 e6 eb 0a 48 c7 c7 dd 96 61 8c 48 89 de e8 c5 16 86 08 31 ed eb d4 cc f3 0f 1e fa 89 f6 48 8b 0c 24 <31> d2 e9 df ea ff ff 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00
RSP: 0018:ffffc90000007838 EFLAGS: 00000046
RAX: 0000000000000000 RBX: ffff888026771e00 RCX: ffffffff8167bd44
RDX: 0000000000000008 RSI: 0000000000000008 RDI: ffffffff90da7500
RBP: 0000000000000008 R08: dffffc0000000000 R09: 1ffffffff21b4ea0
R10: dffffc0000000000 R11: fffffbfff21b4ea1 R12: 0000000000000100
R13: dffffc0000000000 R14: ffff888026772930 R15: 0000000000000001
FS:  0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffcad6dc0d8 CR3: 000000000cb30000 CR4: 00000000003506f0
Call Trace:
 <IRQ>
 instrument_atomic_read include/linux/instrumented.h:68 [inline]
 _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline]
 hlock_class kernel/locking/lockdep.c:228 [inline]
 mark_lock+0x94/0x320 kernel/locking/lockdep.c:4656
 mark_usage kernel/locking/lockdep.c:4599 [inline]
 __lock_acquire+0xd49/0x7c80 kernel/locking/lockdep.c:5091
 lock_acquire+0x197/0x410 kernel/locking/lockdep.c:5754
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
 _raw_spin_lock_irqsave+0xa8/0xf0 kernel/locking/spinlock.c:162
 debug_object_deactivate+0x67/0x350 lib/debugobjects.c:764
 debug_hrtimer_deactivate kernel/time/hrtimer.c:455 [inline]
 debug_deactivate+0x1d/0x1d0 kernel/time/hrtimer.c:511
 __run_hrtimer kernel/time/hrtimer.c:1718 [inline]
 __hrtimer_run_queues+0x2bf/0xc40 kernel/time/hrtimer.c:1814
 hrtimer_interrupt+0x3c9/0x9c0 kernel/time/hrtimer.c:1876
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1077 [inline]
 __sysvec_apic_timer_interrupt+0xfb/0x3b0 arch/x86/kernel/apic/apic.c:1094
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline]
 sysvec_apic_timer_interrupt+0x9f/0xc0 arch/x86/kernel/apic/apic.c:1088
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687
RIP: 0010:check_kcov_mode kernel/kcov.c:182 [inline]
RIP: 0010:write_comp_data kernel/kcov.c:245 [inline]
RIP: 0010:__sanitizer_cov_trace_switch+0x96/0x120 kernel/kcov.c:350
Code: 41 54 53 48 8b 54 24 20 65 4c 8b 05 e4 1a 7e 7e 45 31 c9 eb 08 49 ff c1 4c 39 c8 74 77 4e 8b 54 ce 10 65 44 8b 1d d2 1a 7e 7e <41> 81 e3 00 01 ff 00 74 13 41 81 fb 00 01 00 00 75 d9 41 83 b8 1c
RSP: 0018:ffffc9000cec7200 EFLAGS: 00000202
RAX: 0000000000000002 RBX: dffffc0000000000 RCX: 0000000000000007
RDX: ffffffff8a613743 RSI: ffffffff8e32ccc0 RDI: ffff888057712940
RBP: ffff888057712940 R08: ffff888026771e00 R09: 0000000000000001
R10: 0000000000000003 R11: 0000000080000000 R12: ffffc9000cec7338
R13: 00000000000007c4 R14: fffffffffffffffe R15: ffffc9000cec7320
 xas_find+0x113/0xab0 lib/xarray.c:1246
 find_get_entry mm/filemap.c:2013 [inline]
 find_lock_entries+0x1c7/0xfe0 mm/filemap.c:2114
 shmem_undo_range+0x254/0x1a40 mm/shmem.c:1009
 shmem_truncate_range mm/shmem.c:1136 [inline]
 shmem_evict_inode+0x273/0xa70 mm/shmem.c:1265
 evict+0x486/0x870 fs/inode.c:705
 __dentry_kill+0x431/0x650 fs/dcache.c:611
 dentry_kill+0xb8/0x290 fs/dcache.c:-1
 dput+0xfe/0x1e0 fs/dcache.c:918
 __fput+0x5e5/0x970 fs/file_table.c:392
 task_work_run+0x1ce/0x250 kernel/task_work.c:239
 exit_task_work include/linux/task_work.h:43 [inline]
 do_exit+0x90b/0x23c0 kernel/exit.c:883
 do_group_exit+0x21b/0x2d0 kernel/exit.c:1024
 get_signal+0x12fc/0x1400 kernel/signal.c:2902
 arch_do_signal_or_restart+0x96/0x780 arch/x86/kernel/signal.c:310
 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174
 exit_to_user_mode_prepare+0xf6/0x180 kernel/entry/common.c:210
 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline]
 syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302
 do_syscall_64+0x61/0xb0 arch/x86/entry/common.c:87
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f368a98eec9
Code: Unable to access opcode bytes at 0x7f368a98ee9f.
RSP: 002b:00007ffdeae58f48 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: 0000000000000000 RBX: 00000000000595dc RCX: 00007f368a98eec9
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f368abe5fac
RBP: 0000000000000032 R08: 0000000000745b08 R09: 00000008eae5923f
R10: 00007ffdeae59040 R11: 0000000000000246 R12: 00007f368abe5fac
R13: 00007ffdeae59040 R14: 000000000005960e R15: 00007ffdeae59060
 </TASK>
rcu: rcu_preempt kthread starved for 8840 jiffies! g60537 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:26056 pid:17    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5380 [inline]
 __schedule+0x14d2/0x44d0 kernel/sched/core.c:6699
 schedule+0xbd/0x170 kernel/sched/core.c:6773
 schedule_timeout+0x160/0x280 kernel/time/timer.c:2167
 rcu_gp_fqs_loop+0x302/0x1560 kernel/rcu/tree.c:1667
 rcu_gp_kthread+0x99/0x380 kernel/rcu/tree.c:1866
 kthread+0x2fa/0x390 kernel/kthread.c:388
 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 1 PID: 12519 Comm: kworker/u4:12 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:csd_lock_wait kernel/smp.c:311 [inline]
RIP: 0010:smp_call_function_many_cond+0xddf/0x1130 kernel/smp.c:855
Code: 45 8b 2c 24 44 89 ee 83 e6 01 31 ff e8 da d6 0a 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 15 d3 0a 00 eb 38 f3 90 <42> 0f b6 04 2b 84 c0 75 11 41 f7 04 24 01 00 00 00 74 1e e8 f9 d2
RSP: 0018:ffffc90005c07780 EFLAGS: 00000293
RAX: ffffffff817ac4a7 RBX: 1ffff110171c8791 RCX: ffff88802c801e00
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc90005c07900 R08: ffffffff90da7507 R09: 1ffffffff21b4ea0
R10: dffffc0000000000 R11: fffffbfff21b4ea1 R12: ffff8880b8e43c88
R13: dffffc0000000000 R14: ffff8880b8f3d348 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fce294f0931 CR3: 000000000cb30000 CR4: 00000000003506e0
Call Trace:
 <TASK>
 on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1023
 on_each_cpu include/linux/smp.h:71 [inline]
 text_poke_sync arch/x86/kernel/alternative.c:2222 [inline]
 text_poke_bp_batch+0x848/0x930 arch/x86/kernel/alternative.c:-1
 text_poke_flush arch/x86/kernel/alternative.c:2623 [inline]
 text_poke_finish+0x30/0x50 arch/x86/kernel/alternative.c:2630
 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146
 static_key_enable_cpuslocked+0x123/0x240 kernel/jump_label.c:207
 static_key_enable+0x1a/0x20 kernel/jump_label.c:220
 toggle_allocation_gate+0xaa/0x250 mm/kfence/core.c:831
 process_one_work kernel/workqueue.c:2634 [inline]
 process_scheduled_works+0xa45/0x15b0 kernel/workqueue.c:2711
 worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792
 kthread+0x2fa/0x390 kernel/kthread.c:388
 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
 </TASK>