rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P18727/1:b..l
rcu: (detected by 1, t=10502 jiffies, g=91809, q=756 ncpus=2)
task:syz.5.3340 state:R running task stack:21344 pid:18727 tgid:18727 ppid:13425 task_flags:0x40064c flags:0x00080001
Call Trace:
context_switch kernel/sched/core.c:5248 [inline]
__schedule+0x14bc/0x5000 kernel/sched/core.c:6855
preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7182
irqentry_exit+0x5d8/0x660 kernel/entry/common.c:216
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:lock_acquire+0x16c/0x340 kernel/locking/lockdep.c:5872
Code: 00 00 00 00 9c 8f 44 24 30 f7 44 24 30 00 02 00 00 0f 85 cd 00 00 00 f7 44 24 08 00 02 00 00 74 01 fb 65 48 8b 05 c4 f4 d7 10 <48> 3b 44 24 58 0f 85 e5 00 00 00 48 83 c4 60 5b 41 5c 41 5d 41 5e
RSP: 0018:ffffc9000bafecf8 EFLAGS: 00000206
RAX: 2354ae8a25987f00 RBX: 0000000000000000 RCX: 2354ae8a25987f00
RDX: 000000005a44979c RSI: ffffffff8d94db09 RDI: ffffffff8bbfc000
RBP: ffffffff8173ef25 R08: ffffffff8173ef25 R09: ffffffff8df42000
R10: dffffc0000000000 R11: ffffffff81ad12f0 R12: 0000000000000002
R13: ffffffff8df42000 R14: 0000000000000000 R15: 0000000000000246
rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
rcu_read_lock include/linux/rcupdate.h:867 [inline]
class_rcu_constructor include/linux/rcupdate.h:1195 [inline]
unwind_next_frame+0xc2/0x2390 arch/x86/kernel/unwind_orc.c:479
arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
save_stack+0xf5/0x1f0 mm/page_owner.c:156
__reset_page_owner+0x71/0x1f0 mm/page_owner.c:311
reset_page_owner include/linux/page_owner.h:25 [inline]
free_pages_prepare mm/page_alloc.c:1394 [inline]
free_unref_folios+0xdb3/0x14f0 mm/page_alloc.c:2958
folios_put_refs+0x584/0x670 mm/swap.c:1002
folio_batch_release include/linux/pagevec.h:101 [inline]
shmem_undo_range+0x49e/0x1490 mm/shmem.c:1119
shmem_truncate_range mm/shmem.c:1231 [inline]
shmem_evict_inode+0x272/0xa70 mm/shmem.c:1359
evict+0x5f4/0xae0 fs/inode.c:837
__dentry_kill+0x209/0x660 fs/dcache.c:670
dput+0x19f/0x2b0 fs/dcache.c:912
__fput+0x68e/0xa70 fs/file_table.c:476
task_work_run+0x1d4/0x260 kernel/task_work.c:233
exit_task_work include/linux/task_work.h:40 [inline]
do_exit+0x6c5/0x2310 kernel/exit.c:973
do_group_exit+0x21c/0x2d0 kernel/exit.c:1114
get_signal+0x1285/0x1340 kernel/signal.c:3034
arch_do_signal_or_restart+0x9a/0x7a0 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:41 [inline]
exit_to_user_mode_loop kernel/entry/common.c:75 [inline]
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
irqentry_exit_to_user_mode_prepare include/linux/irq-entry-common.h:270 [inline]
irqentry_exit_to_user_mode include/linux/irq-entry-common.h:339 [inline]
irqentry_exit+0x177/0x660 kernel/entry/common.c:196
exc_page_fault+0xab/0x100 arch/x86/mm/fault.c:1535
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618
RIP: 0033:0x7ff7b358f751
RSP: 002b:0000000000000030 EFLAGS: 00010217
RAX: 0000000000000000 RBX: 00007ff7b37e6090 RCX: 00007ff7b358f749
RDX: 0000000000000000 RSI: 0000000000000030 RDI: 0000000000000600
RBP: 00007ff7b3613f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 00007ff7b37e6128 R14: 00007ff7b37e6090 R15: 00007ffc2ac1d4b8
rcu: rcu_preempt kthread starved for 10327 jiffies! g91809 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:27136 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5248 [inline]
__schedule+0x14bc/0x5000 kernel/sched/core.c:6855
__schedule_loop kernel/sched/core.c:6937 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6952
schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2083
rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2285
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 18860 Comm: syz.9.3371 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:trace_hardirqs_on+0x18/0x40 kernel/trace/trace_preemptirq.c:75
Code: 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 65 8b 05 f5 45 ae 10 85 c0 74 14 48 8b 3c 24 e8 d8 fe ff ff <65> c7 05 dd 45 ae 10 00 00 00 00 e8 c8 28 d5 ff 48 8b 3c 24 e9 6f
RSP: 0018:ffffc90004847c88 EFLAGS: 00000002
RAX: 0000000000000001 RBX: ffff888029f90000 RCX: e44551af20c8b400
RDX: 0000000000000000 RSI: ffffffff8bbfbfe0 RDI: ffffffff8bbfbfa0
RBP: ffffc90004847ed0 R08: ffffffff8f802677 R09: 1ffffffff1f004ce
R10: dffffc0000000000 R11: fffffbfff1f004cf R12: 0000000000000000
R13: 1ffff92000908ffc R14: 00000000ffffffff R15: 00007fff3dd6e278
FS: 0000555579dd2500(0000) GS:ffff8881260c0000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f3cc65d3d58 CR3: 000000005ce6c000 CR4: 0000000000350ef0
Call Trace:
__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:159 [inline]
_raw_spin_unlock_irq+0x23/0x50 kernel/locking/spinlock.c:202
__ia32_sys_rt_sigreturn+0x278/0x860 arch/x86/kernel/signal_64.c:263
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fbe4ad2b829
Code: 64 c7 00 16 00 00 00 b8 ff ff ff ff c3 0f 1f 40 00 90 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 c7 c0 0f 00 00 00 0f 05 <0f> 1f 80 00 00 00 00 48 81 ec 48 01 00 00 49 89 d0 64 48 8b 04 25
RSP: 002b:00007fff3dd6e280 EFLAGS: 00000246 ORIG_RAX: 000000000000000f
RAX: ffffffffffffffda RBX: 00007fbe4bb15720 RCX: 00007fbe4ad2b829
RDX: 00007fff3dd6e280 RSI: 00007fff3dd6e3b0 RDI: 0000000000000011
RBP: ffffffff81aed2d4 R08: 00007fbe4afd0000 R09: 00007fbe4afd2000
R10: 0000000081aed2d8 R11: 0000000000000246 R12: 000000000000000a
R13: 0000000000000000 R14: ffffffff81aeda53 R15: 0000000000002ecc