rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	0-...!: (2 ticks this GP) idle=b09c/1/0x4000000000000000 softirq=16231/16231 fqs=0
rcu: 	(t=10577 jiffies g=9141 q=797 ncpus=2)
rcu: rcu_preempt kthread timer wakeup didn't happen for 10576 jiffies! g9141 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: 	Possible timer handling issue on cpu=0 timer-softirq=5708
rcu: rcu_preempt kthread starved for 10577 jiffies! g9141 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:28440 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5260 [inline]
 __schedule+0x1138/0x5ee0 kernel/sched/core.c:6867
 __schedule_loop kernel/sched/core.c:6949 [inline]
 schedule+0xe7/0x3a0 kernel/sched/core.c:6964
 schedule_timeout+0x123/0x290 kernel/time/sleep_timeout.c:99
 rcu_gp_fqs_loop+0x1ea/0xaf0 kernel/rcu/tree.c:2083
 rcu_gp_kthread+0x26d/0x380 kernel/rcu/tree.c:2285
 kthread+0x3c5/0x780 kernel/kthread.c:463
 ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
 </TASK>
CPU: 0 UID: 0 PID: 5940 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline]
RIP: 0010:smp_call_function_many_cond+0xdfd/0x15e0 kernel/smp.c:877
Code: 57 48 8b 54 24 10 4c 89 74 24 10 49 89 d5 48 89 d5 48 89 54 24 18 49 c1 ed 03 83 e5 07 4d 01 e5 83 c5 03 e8 45 5f 0c 00 f3 90 <41> 0f b6 45 00 40 38 c5 7c 08 84 c0 0f 85 b6 05 00 00 8b 43 08 31
RSP: 0018:ffffc900038676d0 EFLAGS: 00000293
RAX: 0000000000000000 RBX: ffff8880b8540cc0 RCX: ffffffff81b2a071
RDX: ffff888030f90000 RSI: ffffffff81b2a04b RDI: 0000000000000005
RBP: 0000000000000003 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: ffff888030f90b30 R12: dffffc0000000000
R13: ffffed10170a8199 R14: 0000000000000001 R15: 0000000000000001
FS:  0000000000000000(0000) GS:ffff8881248f1000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005647f51dcbe0 CR3: 000000000e184000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 on_each_cpu_cond_mask+0x40/0x90 kernel/smp.c:1043
 __flush_tlb_multi arch/x86/include/asm/paravirt.h:91 [inline]
 flush_tlb_multi arch/x86/mm/tlb.c:1382 [inline]
 flush_tlb_mm_range+0x2f0/0x12c0 arch/x86/mm/tlb.c:1472
 tlb_flush arch/x86/include/asm/tlb.h:23 [inline]
 tlb_flush_mmu_tlbonly include/asm-generic/tlb.h:490 [inline]
 tlb_flush_mmu_tlbonly include/asm-generic/tlb.h:480 [inline]
 tlb_flush_mmu mm/mmu_gather.c:403 [inline]
 tlb_finish_mmu+0x3c9/0x7c0 mm/mmu_gather.c:497
 exit_mmap+0x3f9/0xb60 mm/mmap.c:1290
 __mmput+0x12a/0x410 kernel/fork.c:1173
 mmput+0x62/0x70 kernel/fork.c:1196
 exit_mm kernel/exit.c:581 [inline]
 do_exit+0x7d7/0x2bd0 kernel/exit.c:959
 do_group_exit+0xd3/0x2a0 kernel/exit.c:1112
 get_signal+0x2671/0x26d0 kernel/signal.c:3034
 arch_do_signal_or_restart+0x8f/0x7e0 arch/x86/kernel/signal.c:337
 __exit_to_user_mode_loop kernel/entry/common.c:41 [inline]
 exit_to_user_mode_loop+0x8c/0x540 kernel/entry/common.c:75
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
 syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline]
 do_syscall_64+0x4ee/0xf80 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f728f585853
Code: Unable to access opcode bytes at 0x7f728f585829.
RSP: 002b:00007ffc1847d6b8 EFLAGS: 00000202 ORIG_RAX: 000000000000003d
RAX: fffffffffffffe00 RBX: 000000000000173a RCX: 00007f728f585853
RDX: 0000000040000000 RSI: 00007ffc1847d6cc RDI: 00000000ffffffff
RBP: 00007ffc1847d6cc R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000002
R13: 00007ffc1847d738 R14: 00007ffc1847d9b8 R15: 0000000000000000
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 3892 Comm: kworker/u8:12 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Workqueue: writeback wb_workfn (flush-8:0)
RIP: 0010:check_preemption_disabled+0x25/0xe0 lib/smp_processor_id.c:54
Code: 90 90 90 90 90 41 54 55 53 48 83 ec 08 65 8b 1d d5 11 3a 08 65 8b 05 ca 11 3a 08 a9 ff ff ff 7f 74 0f 48 83 c4 08 89 d8 5b 5d <41> 5c c3 cc cc cc cc 9c 58 f6 c4 02 74 ea 48 89 fd 65 48 8b 05 8a
RSP: 0018:ffffc90000a08d40 EFLAGS: 00000096
RAX: 0000000000000001 RBX: ffff888034148c20 RCX: 0000000000000001
RDX: 0000000000000000 RSI: ffffffff8daa92f6 RDI: ffffffff8bf2b280
RBP: ffff88807501b2c0 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: ffff888034148b30 R12: ffff888034148000
R13: 0000000000000001 R14: 00000000ffffffff R15: 0000000000000006
FS:  0000000000000000(0000) GS:ffff8881249f1000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005647f51dcbe0 CR3: 000000000e184000 CR4: 00000000003526f0
Call Trace:
 <IRQ>
 lockdep_recursion_finish kernel/locking/lockdep.c:470 [inline]
 lock_is_held_type+0xdf/0x150 kernel/locking/lockdep.c:5941
 lock_is_held include/linux/lockdep.h:249 [inline]
 advance_sched+0x7b1/0xc80 net/sched/sch_taprio.c:933
 __run_hrtimer kernel/time/hrtimer.c:1777 [inline]
 __hrtimer_run_queues+0x202/0xc40 kernel/time/hrtimer.c:1841
 hrtimer_interrupt+0x397/0x8e0 kernel/time/hrtimer.c:1903
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1045 [inline]
 __sysvec_apic_timer_interrupt+0x10b/0x3c0 arch/x86/kernel/apic/apic.c:1062
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
 sysvec_apic_timer_interrupt+0x9f/0xc0 arch/x86/kernel/apic/apic.c:1056
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:xas_reload include/linux/xarray.h:1623 [inline]
RIP: 0010:find_get_entry mm/filemap.c:2079 [inline]
RIP: 0010:filemap_get_folios_tag+0x234/0xae0 mm/filemap.c:2332
Code: 0f b6 04 38 84 c0 74 06 0f 8e ec 07 00 00 45 0f b6 65 00 48 8b 44 24 60 bf 3f 00 00 00 44 89 e6 48 89 44 24 10 e8 3c 12 c7 ff <41> 80 fc 3f 0f 87 c2 d4 28 ff e8 ed 17 c7 ff 48 8b 44 24 10 44 89
RSP: 0018:ffffc9000d986e08 EFLAGS: 00000293
RAX: 0000000000000000 RBX: ffffea0001cc43c0 RCX: ffffffff81f7e794
RDX: ffff888034148000 RSI: 000000000000003f RDI: 0000000000000001
RBP: 0000000000000000 R08: 0000000000000001 R09: 000000000000003f
R10: 0000000000000000 R11: ffff888034148b30 R12: 0000000000000000
R13: ffff8880274a0000 R14: ffffc9000d986fe8 R15: dffffc0000000000
 mpage_prepare_extent_to_map+0x399/0x1510 fs/ext4/inode.c:2639
 ext4_do_writepages+0xd1b/0x3c80 fs/ext4/inode.c:2930
 ext4_writepages+0x37a/0x7d0 fs/ext4/inode.c:3026
 do_writepages+0x27a/0x600 mm/page-writeback.c:2598
 __writeback_single_inode+0x168/0x14a0 fs/fs-writeback.c:1737
 writeback_sb_inodes+0x72e/0x1ce0 fs/fs-writeback.c:2030
 __writeback_inodes_wb+0xf8/0x2d0 fs/fs-writeback.c:2107
 wb_writeback+0x799/0xae0 fs/fs-writeback.c:2218
 wb_check_old_data_flush fs/fs-writeback.c:2322 [inline]
 wb_do_writeback fs/fs-writeback.c:2375 [inline]
 wb_workfn+0x8a0/0xbb0 fs/fs-writeback.c:2403
 process_one_work+0x9ba/0x1b20 kernel/workqueue.c:3257
 process_scheduled_works kernel/workqueue.c:3340 [inline]
 worker_thread+0x6c8/0xf10 kernel/workqueue.c:3421
 kthread+0x3c5/0x780 kernel/kthread.c:463
 ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
 </TASK>