syzbot

rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P9087/1:b..l
	(detected by 1, t=10502 jiffies, g=45321, q=43 ncpus=2)
task:syz.1.885       state:R  running task     stack:24728 pid:9087  ppid:7520   flags:0x00004002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5243 [inline]
 __schedule+0x143f/0x4570 kernel/sched/core.c:6560
 preempt_schedule_irq+0xf7/0x1c0 kernel/sched/core.c:6872
 irqentry_exit+0x53/0x80 kernel/entry/common.c:439
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691
RIP: 0010:stack_trace_consume_entry+0x1/0x270 kernel/stacktrace.c:83
Code: ff 89 d9 80 e1 07 80 c1 03 38 c1 0f 8c 7b ff ff ff 48 89 df e8 d0 af 69 00 e9 6e ff ff ff e8 96 26 39 09 66 0f 1f 44 00 00 55 <41> 57 41 56 41 55 41 54 53 48 83 ec 18 48 89 fb 48 ba 00 00 00 00
RSP: 0018:ffffc9000c256c50 EFLAGS: 00000286
RAX: ffffffff81eb2b42 RBX: ffffc9000c256c60 RCX: ffffffff8fe3d000
RDX: ffffffff8ff98801 RSI: ffffffff81eb2b42 RDI: ffffc9000c256d40
RBP: ffffc9000c256cf0 R08: ffffc9000c256f10 R09: ffffc9000c256cb0
R10: 0000000000000000 R11: dffffc0000000001 R12: ffff888030a69dc0
R13: ffffffff81785b30 R14: ffffc9000c256d40 R15: 0000000000000000
 arch_stack_walk+0x101/0x140 arch/x86/kernel/stacktrace.c:27
 stack_trace_save+0x113/0x1c0 kernel/stacktrace.c:122
 save_stack+0xf6/0x1e0 mm/page_owner.c:127
 __reset_page_owner+0x52/0x1a0 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+0x12a6/0x15b0 mm/page_alloc.c:3384
 free_unref_page_list+0x663/0x900 mm/page_alloc.c:3525
 release_pages+0x24c4/0x27a0 mm/swap.c:1035
 __pagevec_release+0x80/0xf0 mm/swap.c:1055
 pagevec_release include/linux/pagevec.h:71 [inline]
 folio_batch_release include/linux/pagevec.h:135 [inline]
 shmem_undo_range+0x865/0x2390 mm/shmem.c:946
 shmem_truncate_range mm/shmem.c:1062 [inline]
 shmem_evict_inode+0x265/0xa60 mm/shmem.c:1171
 evict+0x529/0x930 fs/inode.c:705
 __dentry_kill+0x436/0x650 fs/dcache.c:611
 dentry_kill+0xbb/0x290 fs/dcache.c:-1
 dput+0xfb/0x1d0 fs/dcache.c:918
 __fput+0x62e/0x8d0 fs/file_table.c:328
 task_work_run+0x246/0x300 kernel/task_work.c:203
 exit_task_work include/linux/task_work.h:39 [inline]
 do_exit+0xa6e/0x26a0 kernel/exit.c:871
 do_group_exit+0x202/0x2b0 kernel/exit.c:1021
 get_signal+0x16cb/0x17a0 kernel/signal.c:2871
 arch_do_signal_or_restart+0xb0/0x1a10 arch/x86/kernel/signal.c:871
 exit_to_user_mode_loop+0x6a/0x100 kernel/entry/common.c:174
 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210
 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline]
 syscall_exit_to_user_mode+0x60/0x270 kernel/entry/common.c:303
 do_syscall_64+0x47/0xb0 arch/x86/entry/common.c:87
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f81b638d169
RSP: 002b:00007f81b71d1038 EFLAGS: 00000246 ORIG_RAX: 000000000000012b
RAX: 0000000000010106 RBX: 00007f81b65a6080 RCX: 00007f81b638d169
RDX: 0000000000010106 RSI: 00002000000000c0 RDI: 0000000000000003
RBP: 00007f81b640e2a0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f81b65a6080 R15: 00007ffedf20e668
 </TASK>
rcu: rcu_preempt kthread starved for 10282 jiffies! g45321 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:26712 pid:16    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5243 [inline]
 __schedule+0x143f/0x4570 kernel/sched/core.c:6560
 schedule+0xbf/0x180 kernel/sched/core.c:6636
 schedule_timeout+0x1b9/0x300 kernel/time/timer.c:1965
 rcu_gp_fqs_loop+0x2d2/0x1150 kernel/rcu/tree.c:1706
 rcu_gp_kthread+0xa3/0x3b0 kernel/rcu/tree.c:1905
 kthread+0x28d/0x320 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: 1 PID: 9161 Comm: syz.0.908 Not tainted 6.1.131-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
RIP: 0010:lock_is_held_type+0x3/0x180 kernel/locking/lockdep.c:5690
Code: 48 c7 c7 e0 1b 0c 8b 48 c7 c6 20 1c 0c 8b e8 d4 3b a1 f6 0f 0b eb bf e8 ab fd ff ff 66 2e 0f 1f 84 00 00 00 00 00 90 55 41 57 <41> 56 41 55 41 54 53 48 83 ec 10 65 48 8b 04 25 28 00 00 00 48 89
RSP: 0018:ffffc9000c5efa08 EFLAGS: 00000202
RAX: 0000000000000001 RBX: 0000000000000004 RCX: ffff8880600c3b80
RDX: 0000000000000000 RSI: 00000000ffffffff RDI: ffffffff8d32e640
RBP: ffffc9000c5efb30 R08: ffffffff8156fea2 R09: ffffed100c018771
R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000000
R13: ffff8880600c3b80 R14: 0000000000000035 R15: 1ffff920018bdf4c
FS:  00007f2ec37ff6c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200001000000 CR3: 0000000062b1b000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 </IRQ>
 <TASK>
 lock_is_held include/linux/lockdep.h:283 [inline]
 __might_resched+0xf0/0x780 kernel/sched/core.c:9919
 try_to_freeze include/linux/freezer.h:53 [inline]
 get_signal+0x192/0x17a0 kernel/signal.c:2661
 arch_do_signal_or_restart+0xb0/0x1a10 arch/x86/kernel/signal.c:871
 exit_to_user_mode_loop+0x6a/0x100 kernel/entry/common.c:174
 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210
 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline]
 syscall_exit_to_user_mode+0x60/0x270 kernel/entry/common.c:303
 do_syscall_64+0x47/0xb0 arch/x86/entry/common.c:87
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f2ec398d169
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f2ec37ff0e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007f2ec3ba5fa8 RCX: 00007f2ec398d169
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f2ec3ba5fa8
RBP: 00007f2ec3ba5fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f2ec3ba5fac
R13: 0000000000000000 R14: 00007ffd5c993d10 R15: 00007ffd5c993df8
 </TASK>