rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P4277/1:b..l P4265/1:b..l
	(detected by 0, t=10503 jiffies, g=20417, q=135 ncpus=2)
task:syz-executor    state:R  running task     stack:22608 pid:4265  ppid:4263   flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5245 [inline]
 __schedule+0x11d1/0x40e0 kernel/sched/core.c:6562
 preempt_schedule_common+0x82/0xd0 kernel/sched/core.c:6731
 preempt_schedule+0xbc/0xd0 kernel/sched/core.c:6755
 preempt_schedule_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:34
 unwind_next_frame+0x1892/0x20b0 arch/x86/kernel/unwind_orc.c:629
 arch_stack_walk+0x10c/0x140 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0xa6/0xf0 kernel/stacktrace.c:122
 save_stack+0x121/0x230 mm/page_owner.c:127
 __reset_page_owner+0x51/0x1a0 mm/page_owner.c:148
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1459 [inline]
 free_pcp_prepare mm/page_alloc.c:1509 [inline]
 free_unref_page_prepare+0x8b4/0x9a0 mm/page_alloc.c:3384
 free_unref_page_list+0xbb/0x8e0 mm/page_alloc.c:3525
 release_pages+0x1fa6/0x2220 mm/swap.c:1035
 __pagevec_release+0x6d/0xe0 mm/swap.c:1055
 pagevec_release include/linux/pagevec.h:71 [inline]
 folio_batch_release include/linux/pagevec.h:135 [inline]
 shmem_undo_range+0x7c2/0x20c0 mm/shmem.c:946
 shmem_truncate_range mm/shmem.c:1062 [inline]
 shmem_evict_inode+0x25b/0xa80 mm/shmem.c:1171
 evict+0x4c9/0x8d0 fs/inode.c:705
 do_unlinkat+0x388/0x580 fs/namei.c:4405
 __do_sys_unlink fs/namei.c:4446 [inline]
 __se_sys_unlink fs/namei.c:4444 [inline]
 __x64_sys_unlink+0x45/0x50 fs/namei.c:4444
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fad78399fa7
RSP: 002b:00007ffd1a01dcb8 EFLAGS: 00000206 ORIG_RAX: 0000000000000057
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fad78399fa7
RDX: 00007ffd1a01dce0 RSI: 00007ffd1a01dd70 RDI: 00007ffd1a01dd70
RBP: 00007ffd1a01dd70 R08: 00007ffd1a01ed70 R09: 00000000ffffffff
R10: 0000000000000100 R11: 0000000000000206 R12: 00007ffd1a01ee00
R13: 00007fad7840471f R14: 000000000003252c R15: 00007ffd1a01ee40
 </TASK>
task:syz-executor    state:R  running task     stack:20208 pid:4277  ppid:4260   flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5245 [inline]
 __schedule+0x11d1/0x40e0 kernel/sched/core.c:6562
 preempt_schedule_irq+0xbb/0x160 kernel/sched/core.c:6874
 irqentry_exit+0x63/0x70 kernel/entry/common.c:439
 asm_sysvec_reschedule_ipi+0x16/0x20 arch/x86/include/asm/idtentry.h:696
RIP: 0010:inode_permission+0xf9/0x480 fs/namei.c:536
Code: c0 0f 85 db 02 00 00 41 8b 2f 31 ff 89 ee e8 0e 5e 9e ff 85 ed 0f 85 99 01 00 00 e8 a1 5a 9e ff 4c 89 f7 89 de 48 83 c4 10 5b <41> 5c 41 5d 41 5e 41 5f 5d e9 79 72 e7 01 4d 8d 66 28 4c 89 e0 48
RSP: 0018:ffffc90003f87810 EFLAGS: 00000282
RAX: ffffffff81e417cf RBX: ffffc90003f87c50 RCX: ffff88802fffd940
RDX: 0000000000000000 RSI: 0000000000000081 RDI: ffff8880689333c0
RBP: 0000000000000000 R08: ffff88802fffd940 R09: 0000000000000002
R10: 000000000000002f R11: 0000000000000000 R12: 1ffff1100d126678
R13: ffffffff8c9d7460 R14: ffff8880689333c0 R15: ffff88806893340c
 may_lookup fs/namei.c:1724 [inline]
 link_path_walk+0x280/0xe70 fs/namei.c:2275
 path_openat+0x286/0x2ee0 fs/namei.c:3787
 do_filp_open+0x1f1/0x430 fs/namei.c:3818
 do_sys_openat2+0x150/0x4b0 fs/open.c:1320
 do_sys_open fs/open.c:1336 [inline]
 __do_sys_openat fs/open.c:1352 [inline]
 __se_sys_openat fs/open.c:1347 [inline]
 __x64_sys_openat+0x135/0x160 fs/open.c:1347
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f82f259a1dc
RSP: 002b:00007fff69071920 EFLAGS: 00000206 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f82f260471f RCX: 00007f82f259a1dc
RDX: 0000000000090800 RSI: 00007fff69072ad0 RDI: 00000000ffffff9c
RBP: 00007fff69072abc R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 00007fff69072ad0
R13: 00007f82f260471f R14: 0000000000032f4a R15: 00007fff69072b10
 </TASK>
rcu: rcu_preempt kthread starved for 10573 jiffies! g20417 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:26416 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:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 6035 Comm: syz.5.444 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:rcu_read_lock_held_common kernel/rcu/update.c:306 [inline]
RIP: 0010:rcu_read_lock_held+0x0/0x40 kernel/rcu/update.c:309
Code: a0 8f e8 83 f7 67 00 eb cf 90 0f b6 05 c1 5d b4 0c c3 0f 1f 84 00 00 00 00 00 e8 6b 3e 01 00 e9 56 42 01 00 66 0f 1f 44 00 00 <53> e8 2a f4 c0 08 85 c0 74 26 31 db e8 9f 0c 01 00 84 c0 74 20 e8
RSP: 0018:ffffc900001e0c28 EFLAGS: 00000046
RAX: ffffffff8156129d RBX: 0000000000000001 RCX: 0000000000010000
RDX: ffff888028893b80 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: dffffc0000000000 R09: 1ffffffff215e648
R10: dffffc0000000000 R11: fffffbfff215e649 R12: ffff888077601be8
R13: ffff888055b5c780 R14: ffff88802a4cdf78 R15: 0000000000000001
FS:  00007fbcdff866c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f457bbe8600 CR3: 00000000563a3000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 pid_task+0x9d/0x140 kernel/pid.c:401
 send_sigqueue+0x137/0x610 kernel/signal.c:1978
 posix_timer_event kernel/time/posix-timers.c:360 [inline]
 posix_timer_fn+0x16a/0x3d0 kernel/time/posix-timers.c:386
 __run_hrtimer kernel/time/hrtimer.c:1747 [inline]
 __hrtimer_run_queues+0x560/0xd70 kernel/time/hrtimer.c:1811
 hrtimer_interrupt+0x3c5/0x9c0 kernel/time/hrtimer.c:1873
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1107 [inline]
 __sysvec_apic_timer_interrupt+0x153/0x5a0 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: 00 00 00 66 90 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 ae 54 2e f7 48 89 df e8 f6 1c 2f f7 e8 71 6d 52 f7 fb bf 01 00 00 00 <e8> 96 7d 22 f7 65 8b 05 57 01 cc 75 85 c0 74 02 5b c3 e8 a4 15 ca
RSP: 0018:ffffc900039d7b98 EFLAGS: 00000282
RAX: 42ed5b8d6f259800 RBX: ffff888078735c80 RCX: 42ed5b8d6f259800
RDX: dffffc0000000000 RSI: ffffffff8a8c1220 RDI: 0000000000000001
RBP: ffff888078736118 R08: ffff888078735c83 R09: 1ffff1100f0e6b90
R10: dffffc0000000000 R11: ffffed100f0e6b91 R12: 1ffff1100f0e6c23
R13: 0000000000000021 R14: dffffc0000000000 R15: 0000000000000000
 spin_unlock_irq include/linux/spinlock.h:401 [inline]
 get_signal+0x1163/0x1350 kernel/signal.c:2874
 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: 0033:0x7fbcdf19aeb7
Code: 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 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 e8 ff ff ff f7 d8 64 89
RSP: 002b:00007fbcdff860e8 EFLAGS: 00000246
RAX: 00000000000000ca RBX: 00007fbcdf415fa8 RCX: 00007fbcdf19aeb9
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fbcdf415fa8
RBP: 00007fbcdf415fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fbcdf416038 R14: 00007ffc359cca50 R15: 00007ffc359ccb38
 </TASK>