rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	(detected by 0, t=10502 jiffies, g=33053, q=151 ncpus=2)
rcu: All QSes seen, last rcu_preempt kthread activity 10502 (4294981981-4294971479), jiffies_till_next_fqs=1, root ->qsmask 0x0
rcu: rcu_preempt kthread starved for 10502 jiffies! g33053 f0x2 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:27128 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5396 [inline]
 __schedule+0x16f5/0x4d00 kernel/sched/core.c:6785
 __schedule_loop kernel/sched/core.c:6863 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:6878
 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99
 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2054
 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2256
 kthread+0x70e/0x8a0 kernel/kthread.c:464
 ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </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 UID: 0 PID: 9038 Comm: syz.4.970 Not tainted 6.15.0-next-20250606-syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:__kasan_check_byte+0x6/0x40 mm/kasan/common.c:555
Code: 84 da fe ff ff 48 ff c8 49 89 c4 e9 cf fe ff ff 0f 1f 40 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 66 0f 1f 00 41 56 <53> 48 89 f3 49 89 fe e8 5e 14 00 00 84 c0 75 16 be 01 00 00 00 4c
RSP: 0018:ffffc90000a08b50 EFLAGS: 00000002
RAX: 0000000000000001 RBX: 0000000000000000 RCX: 35879107230ac600
RDX: 0000000000000000 RSI: ffffffff8b694a07 RDI: ffffffff99c55188
RBP: ffffffff84c8379a R08: 0000000000000001 R09: 0000000000000000
R10: ffffc90000a08cb0 R11: fffff52000141198 R12: 0000000000000000
R13: ffffffff99c55188 R14: 0000000000000000 R15: 0000000000000001
FS:  00007f46435f96c0(0000) GS:ffff888125d4d000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fcea1d2cff0 CR3: 00000000799e6000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 kasan_check_byte include/linux/kasan.h:399 [inline]
 lock_acquire+0x8d/0x360 kernel/locking/lockdep.c:5845
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
 _raw_spin_lock_irqsave+0xa7/0xf0 kernel/locking/spinlock.c:162
 debug_object_deactivate+0x9a/0x250 lib/debugobjects.c:873
 debug_hrtimer_deactivate kernel/time/hrtimer.c:450 [inline]
 debug_deactivate+0x1d/0x200 kernel/time/hrtimer.c:490
 __run_hrtimer kernel/time/hrtimer.c:1729 [inline]
 __hrtimer_run_queues+0x2b0/0xc60 kernel/time/hrtimer.c:1825
 hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1887
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1039 [inline]
 __sysvec_apic_timer_interrupt+0x108/0x410 arch/x86/kernel/apic/apic.c:1056
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline]
 sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1050
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:160 [inline]
RIP: 0010:_raw_spin_unlock_irq+0x29/0x50 kernel/locking/spinlock.c:202
Code: 90 f3 0f 1e fa 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 3a f8 34 f6 48 89 df e8 92 8f 35 f6 e8 bd 9d 5e f6 fb bf 01 00 00 00 <e8> c2 89 27 f6 65 8b 05 bb e2 33 07 85 c0 74 07 5b c3 cc cc cc cc
RSP: 0018:ffffc90003e8f730 EFLAGS: 00000286
RAX: 35879107230ac600 RBX: ffff88803131aad8 RCX: 35879107230ac600
RDX: 0000000000000006 RSI: ffffffff8d984053 RDI: 0000000000000001
RBP: ffffc90003e8f870 R08: ffffffff8fa126f7 R09: 1ffffffff1f424de
R10: dffffc0000000000 R11: fffffbfff1f424df R12: ffffc90003e8f7c0
R13: 0000000000000cc0 R14: 0000000000000cc0 R15: 00000003fffffffc
 spin_unlock_irq include/linux/spinlock.h:401 [inline]
 shmem_add_to_page_cache+0x863/0xb10 mm/shmem.c:916
 shmem_alloc_and_add_folio+0x846/0xf60 mm/shmem.c:1916
 shmem_get_folio_gfp+0x59d/0x1660 mm/shmem.c:2532
 shmem_get_folio mm/shmem.c:2638 [inline]
 shmem_write_begin+0xf7/0x2b0 mm/shmem.c:3288
 generic_perform_write+0x2c4/0x910 mm/filemap.c:4112
 shmem_file_write_iter+0xf8/0x120 mm/shmem.c:3463
 new_sync_write fs/read_write.c:593 [inline]
 vfs_write+0x54b/0xa90 fs/read_write.c:686
 ksys_write+0x145/0x250 fs/read_write.c:738
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f464278d3df
Code: 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 f9 92 02 00 48 8b 54 24 18 48 8b 74 24 10 41 89 c0 8b 7c 24 08 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 31 44 89 c7 48 89 44 24 08 e8 4c 93 02 00 48
RSP: 002b:00007f46435f8df0 EFLAGS: 00000293 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000001000000 RCX: 00007f464278d3df
RDX: 0000000001000000 RSI: 00007f4638000000 RDI: 0000000000000003
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000009600
R10: 0000200000009682 R11: 0000000000000293 R12: 0000000000000003
R13: 00007f46435f8ef0 R14: 00007f46435f8eb0 R15: 00007f4638000000
 </TASK>