rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P24181/1:b..l P24205/1:b..l
rcu: (detected by 1, t=10502 jiffies, g=120805, q=439 ncpus=2)
task:syz.9.3954 state:R running task stack:26888 pid:24205 tgid:24199 ppid:23026 task_flags:0x40044c flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5325 [inline]
__schedule+0x1798/0x4cc0 kernel/sched/core.c:6929
preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:7113
preempt_schedule+0xae/0xc0 kernel/sched/core.c:7137
preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12
__raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline]
_raw_spin_unlock+0x3f/0x50 kernel/locking/spinlock.c:186
spin_unlock include/linux/spinlock.h:391 [inline]
zap_pte_range mm/memory.c:1884 [inline]
zap_pmd_range mm/memory.c:1946 [inline]
zap_pud_range mm/memory.c:1975 [inline]
zap_p4d_range mm/memory.c:1996 [inline]
unmap_page_range+0x3a7f/0x4370 mm/memory.c:2017
unmap_single_vma mm/memory.c:2060 [inline]
unmap_vmas+0x399/0x580 mm/memory.c:2104
exit_mmap+0x240/0xb40 mm/mmap.c:1280
__mmput+0x118/0x430 kernel/fork.c:1133
exit_mm+0x1da/0x2c0 kernel/exit.c:582
do_exit+0x648/0x2300 kernel/exit.c:954
do_group_exit+0x21c/0x2d0 kernel/exit.c:1107
get_signal+0x1285/0x1340 kernel/signal.c:3034
arch_do_signal_or_restart+0xa0/0x790 arch/x86/kernel/signal.c:337
exit_to_user_mode_loop+0x72/0x130 kernel/entry/common.c:40
exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline]
do_syscall_64+0x2bd/0xfa0 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fe9f078efc9
RSP: 002b:00007fe9f157e0e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007fe9f09e6098 RCX: 00007fe9f078efc9
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fe9f09e6098
RBP: 00007fe9f09e6090 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fe9f09e6128 R14: 00007ffc75a540f0 R15: 00007ffc75a541d8
task:syz.0.3949 state:R running task stack:25800 pid:24181 tgid:24180 ppid:16459 task_flags:0x40054c flags:0x00080003
Call Trace:
context_switch kernel/sched/core.c:5325 [inline]
__schedule+0x1798/0x4cc0 kernel/sched/core.c:6929
preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7256
irqentry_exit+0x6f/0x90 kernel/entry/common.c:211
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:__preempt_count_add kernel/rcu/tree.c:747 [inline]
RIP: 0010:rcu_is_watching+0x6/0xb0 kernel/rcu/tree.c:750
Code: e8 2f a1 1b 03 eb cc 66 66 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 41 57 <41> 56 53 65 ff 05 e0 cf c7 10 e8 ab fa 9f 09 89 c3 83 f8 08 73 65
RSP: 0018:ffffc9000b17f078 EFLAGS: 00000202
RAX: 0000000000000001 RBX: ffffffff822e6d69 RCX: ffff88805657bc80
RDX: 0000000000000001 RSI: ffffffff8d8f39e4 RDI: ffffffff8bbf0760
RBP: ffffc9000b17f1b0 R08: 0000000000000000 R09: ffffffff822e6d69
R10: dffffc0000000000 R11: fffff940002224f1 R12: 000000000000000c
R13: dffffc0000000000 R14: ffff888028178010 R15: ffffc9000b17f3e8
rcu_read_lock include/linux/rcupdate.h:868 [inline]
percpu_ref_put_many include/linux/percpu-refcount.h:330 [inline]
percpu_ref_put+0x47/0x180 include/linux/percpu-refcount.h:351
__mem_cgroup_uncharge_folios+0xf0/0x1c0 mm/memcontrol.c:4903
mem_cgroup_uncharge_folios include/linux/memcontrol.h:690 [inline]
folios_put_refs+0x57c/0x670 mm/swap.c:1001
folio_batch_release include/linux/pagevec.h:101 [inline]
shmem_undo_range+0x49e/0x14b0 mm/shmem.c:1120
shmem_truncate_range mm/shmem.c:1232 [inline]
shmem_evict_inode+0x272/0xa70 mm/shmem.c:1360
evict+0x504/0x9c0 fs/inode.c:810
__dentry_kill+0x209/0x660 fs/dcache.c:669
dput+0x19f/0x2b0 fs/dcache.c:911
__fput+0x68e/0xa70 fs/file_table.c:476
task_work_run+0x1d4/0x260 kernel/task_work.c:227
exit_task_work include/linux/task_work.h:40 [inline]
do_exit+0x6b5/0x2300 kernel/exit.c:966
do_group_exit+0x21c/0x2d0 kernel/exit.c:1107
get_signal+0x1285/0x1340 kernel/signal.c:3034
arch_do_signal_or_restart+0xa0/0x790 arch/x86/kernel/signal.c:337
exit_to_user_mode_loop+0x72/0x130 kernel/entry/common.c:40
exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline]
do_syscall_64+0x2bd/0xfa0 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f254f18efc9
RSP: 002b:00007f2550099038 EFLAGS: 00000246 ORIG_RAX: 0000000000000009
RAX: 0000200000000000 RBX: 00007f254f3e5fa0 RCX: 00007f254f18efc9
RDX: b635773f06ebbeee RSI: 0000000000b36000 RDI: 0000200000000000
RBP: 00007f254f211f91 R08: ffffffffffffffff R09: 0000000032cc0000
R10: 0000000000008031 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f254f3e6038 R14: 00007f254f3e5fa0 R15: 00007ffedd672d38
rcu: rcu_preempt kthread starved for 10598 jiffies! g120805 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:27088 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5325 [inline]
__schedule+0x1798/0x4cc0 kernel/sched/core.c:6929
__schedule_loop kernel/sched/core.c:7011 [inline]
schedule+0x165/0x360 kernel/sched/core.c:7026
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+0x4bc/0x870 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
rcu: Stack dump where RCU GP kthread last ran:
CPU: 1 UID: 0 PID: 24191 Comm: syz.3.3952 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
RIP: 0010:trace_lock_acquire include/trace/events/lock.h:24 [inline]
RIP: 0010:lock_acquire+0x58/0x360 kernel/locking/lockdep.c:5831
Code: 8b 05 fc cd d0 10 48 89 44 24 58 0f 1f 44 00 00 65 8b 05 ff cd d0 10 83 f8 08 0f 83 b8 01 00 00 89 c0 48 0f a3 05 28 86 df 0d <73> 16 e8 f1 fd 08 00 84 c0 75 0d f6 05 66 92 c9 0d 01 0f 84 d7 01
RSP: 0018:ffffc9000b7bf848 EFLAGS: 00000297
RAX: 0000000000000001 RBX: 0000000000000000 RCX: 0000000000000001
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff88802f78d7e0
RBP: ffffffff820d5e00 R08: 0000000000000001 R09: 0000000000000000
R10: dffffc0000000000 R11: fffff520016f7f3e R12: 0000000000000001
R13: ffff88802f78d7e0 R14: 0000000000000000 R15: 0000000000000001
FS: 00007f47e10516c0(0000) GS:ffff88812623e000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f7f2620fa10 CR3: 0000000037ca3000 CR4: 0000000000350ef0
Call Trace:
__might_fault+0xcc/0x130 mm/memory.c:7081
__copy_to_user include/linux/uaccess.h:142 [inline]
save_xstate_epilog arch/x86/kernel/fpu/signal.c:121 [inline]
copy_fpstate_to_sigframe+0xa88/0xce0 arch/x86/kernel/fpu/signal.c:232
get_sigframe+0x58d/0x7d0 arch/x86/kernel/signal.c:163
x64_setup_rt_frame+0x15b/0xd40 arch/x86/kernel/signal_64.c:175
setup_rt_frame arch/x86/kernel/signal.c:250 [inline]
handle_signal arch/x86/kernel/signal.c:294 [inline]
arch_do_signal_or_restart+0x3f1/0x790 arch/x86/kernel/signal.c:339
exit_to_user_mode_loop+0x72/0x130 kernel/entry/common.c:40
exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline]
do_syscall_64+0x2bd/0xfa0 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f47e018efc7
Code: ff ff 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
RSP: 002b:00007f47e10510e8 EFLAGS: 00000246
RAX: 00000000000000ca RBX: 00007f47e03e5fa8 RCX: 00007f47e018efc9
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f47e03e5fa8
RBP: 00007f47e03e5fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f47e03e6038 R14: 00007fffc984a010 R15: 00007fffc984a0f8