rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	1-...!: (1 GPs behind) idle=91ec/1/0x4000000000000002 softirq=153679/153680 fqs=6
	(detected by 0, t=10502 jiffies, g=227529, q=57 ncpus=2)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 10498 Comm: syz.0.10138 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:arch_irqs_disabled_flags arch/x86/include/asm/irqflags.h:125 [inline]
RIP: 0010:arch_irqs_disabled arch/x86/include/asm/irqflags.h:132 [inline]
RIP: 0010:ct_irq_enter_irqson+0xe1/0x170 kernel/context_tracking.c:408
Code: d5 17 de ff e8 60 50 82 08 e8 cb 14 de ff 48 b8 08 00 00 00 00 fc ff df c6 04 03 00 48 c7 44 24 40 00 00 00 00 9c 8f 44 24 40 <4c> 8b 64 24 40 c6 04 03 f8 4c 89 e6 48 81 e6 00 02 00 00 31 ff e8
RSP: 0018:ffffc90003ec7100 EFLAGS: 00000002
RAX: dffffc0000000008 RBX: 1ffff920007d8e20 RCX: 1c6710313862ec00
RDX: 0000000000000000 RSI: ffffffff8a94df40 RDI: ffffffff8adf0f60
RBP: ffffc90003ec71a8 R08: ffff8880b8f3580b R09: 1ffff110171e6b01
R10: dffffc0000000000 R11: ffffed10171e6b02 R12: dffffc0000000000
R13: 0000000000000001 R14: dffffc0000000000 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f15c0186a90 CR3: 0000000017774000 CR4: 00000000003506e0
DR0: 0000200000000300 DR1: 0000200000000300 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff1 DR7: 0000000000000600
Call Trace:
 <TASK>
 trace_irq_enable_rcuidle+0x9f/0x140 include/trace/events/preemptirq.h:40
 trace_hardirqs_on+0x24/0x40 kernel/trace/trace_preemptirq.c:44
 asm_sysvec_irq_work+0x16/0x20 arch/x86/include/asm/idtentry.h:728
RIP: 0010:rcu_read_unlock_special+0x7f/0x510 kernel/rcu/tree_plugin.h:685
Code: eb 03 48 b8 f1 f1 f1 f1 f8 f2 f2 f2 4a 89 04 2b 42 c7 44 2b 08 f8 f3 f3 f3 65 44 8b 35 e2 33 95 7e 41 f7 c6 00 00 f0 00 74 40 <48> c7 44 24 40 0e 36 e0 45 4a c7 04 2b 00 00 00 00 42 c7 44 2b 08
RSP: 0018:ffffc90003ec72a0 EFLAGS: 00000206
RAX: 1c6710313862ec00 RBX: 1ffff920007d8e5c RCX: 1c6710313862ec00
RDX: dffffc0000000000 RSI: ffffffff8a8c1220 RDI: ffffffff8adf0f60
RBP: ffffc90003ec7398 R08: ffffffff90af6247 R09: 1ffffffff215ec48
R10: dffffc0000000000 R11: fffffbfff215ec49 R12: 0000000000000246
R13: dffffc0000000000 R14: ffff8880b8f3b900 R15: 0000000000000002
 __rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:426
 rcu_read_unlock include/linux/rcupdate.h:823 [inline]
 __folio_memcg_unlock+0xea/0x110 mm/memcontrol.c:2151
 page_remove_rmap+0x7e3/0xea0 mm/rmap.c:1462
 zap_pte_range mm/memory.c:1451 [inline]
 zap_pmd_range mm/memory.c:1572 [inline]
 zap_pud_range mm/memory.c:1601 [inline]
 zap_p4d_range mm/memory.c:1622 [inline]
 unmap_page_range+0x114a/0x2500 mm/memory.c:1643
 unmap_vmas+0x260/0x390 mm/memory.c:1728
 exit_mmap+0x20d/0x960 mm/mmap.c:3250
 __mmput+0x118/0x3c0 kernel/fork.c:1205
 exit_mm+0x1fe/0x2d0 kernel/exit.c:565
 do_exit+0x905/0x2480 kernel/exit.c:867
 do_group_exit+0x217/0x2d0 kernel/exit.c:1022
 get_signal+0x1272/0x1350 kernel/signal.c:2871
 arch_do_signal_or_restart+0xc4/0x1350 arch/x86/kernel/signal.c:871
 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174
 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210
 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline]
 syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:303
 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:82
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f74a859c799
Code: Unable to access opcode bytes at 0x7f74a859c76f.
RSP: 002b:00007f74a67d50e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007f74a8816098 RCX: 00007f74a859c799
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f74a8816098
RBP: 00007f74a8816090 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f74a8816128 R14: 00007ffd841dc550 R15: 00007ffd841dc638
 </TASK>
rcu: rcu_preempt kthread starved for 10490 jiffies! g227529 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->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:R  running task     stack:27024 pid:16    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5245 [inline]
 __schedule+0x11d1/0x40e0 kernel/sched/core.c:6562
 schedule+0xb9/0x180 kernel/sched/core.c:6638
 schedule_timeout+0x184/0x2d0 kernel/time/timer.c:2168
 rcu_gp_fqs_loop+0x303/0x1340 kernel/rcu/tree.c:1706
 rcu_gp_kthread+0x99/0x3b0 kernel/rcu/tree.c:1905
 kthread+0x29d/0x330 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:
CPU: 0 PID: 4990 Comm: kworker/u4:28 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Workqueue: writeback wb_workfn (flush-8:0)
RIP: 0010:native_safe_halt arch/x86/include/asm/irqflags.h:51 [inline]
RIP: 0010:arch_safe_halt arch/x86/include/asm/irqflags.h:89 [inline]
RIP: 0010:kvm_wait+0x159/0x1b0 arch/x86/kernel/kvm.c:1064
Code: 89 df 48 89 f8 48 c1 e8 03 42 0f b6 04 30 84 c0 75 4b 0f b6 1f e8 97 38 50 00 44 38 e3 75 10 66 90 0f 00 2d 59 ce 50 09 fb f4 <e9> 16 ff ff ff fb e9 10 ff ff ff e8 37 62 f4 08 89 f9 80 e1 07 38
RSP: 0018:ffffc9000deae440 EFLAGS: 00000246
RAX: 85e48ae0b9da5b00 RBX: 0000000000000003 RCX: 85e48ae0b9da5b00
RDX: dffffc0000000000 RSI: ffffffff8a8c1220 RDI: ffffffff8adf0f60
RBP: ffffc9000deae4f0 R08: ffffffff90af6247 R09: 1ffffffff215ec48
R10: dffffc0000000000 R11: fffffbfff215ec49 R12: 0000000000000003
R13: ffff8880b8e3b954 R14: dffffc0000000000 R15: 1ffff92001bd5c88
FS:  0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f15c028435d CR3: 00000000770ac000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <TASK>
 pv_wait arch/x86/include/asm/paravirt.h:603 [inline]
 pv_wait_head_or_lock kernel/locking/qspinlock_paravirt.h:470 [inline]
 __pv_queued_spin_lock_slowpath+0x616/0x9c0 kernel/locking/qspinlock.c:511
 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:591 [inline]
 queued_spin_lock_slowpath+0x43/0x50 arch/x86/include/asm/qspinlock.h:51
 queued_spin_lock include/asm-generic/qspinlock.h:114 [inline]
 do_raw_spin_lock+0x265/0x2f0 kernel/locking/spinlock_debug.c:115
 page_vma_mapped_walk+0x14db/0x1700 mm/page_vma_mapped.c:-1
 page_vma_mkclean_one+0x368/0x6a0 mm/rmap.c:958
 page_mkclean_one+0x1ec/0x3a0 mm/rmap.c:1018
 rmap_walk_file+0x3e8/0x730 mm/rmap.c:2499
 rmap_walk mm/rmap.c:2517 [inline]
 folio_mkclean+0x1e1/0x360 mm/rmap.c:1050
 folio_clear_dirty_for_io+0x203/0xc50 mm/page-writeback.c:2886
 mpage_submit_page+0x8a/0x210 fs/ext4/inode.c:2122
 mpage_process_page_bufs+0x6d8/0x8b0 fs/ext4/inode.c:2256
 mpage_prepare_extent_to_map+0xb34/0x1630 fs/ext4/inode.c:2681
 ext4_writepages+0xab3/0x2f40 fs/ext4/inode.c:2809
 do_writepages+0x3ba/0x640 mm/page-writeback.c:2491
 __writeback_single_inode+0x156/0x1160 fs/fs-writeback.c:1622
 writeback_sb_inodes+0xb30/0x1850 fs/fs-writeback.c:1913
 __writeback_inodes_wb+0x12a/0x3f0 fs/fs-writeback.c:1984
 wb_writeback+0x494/0xd50 fs/fs-writeback.c:2089
 wb_check_old_data_flush fs/fs-writeback.c:2189 [inline]
 wb_do_writeback fs/fs-writeback.c:2242 [inline]
 wb_workfn+0xb68/0xee0 fs/fs-writeback.c:2270
 process_one_work+0x8a2/0x1160 kernel/workqueue.c:2292
 worker_thread+0xaa2/0x1270 kernel/workqueue.c:2439
 kthread+0x29d/0x330 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>