rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5843/1:b..l
(detected by 1, t=10502 jiffies, g=15245, q=901)
task:syz.5.375 state:R running task stack:25792 pid: 5843 ppid: 4852 flags:0x00004002
Call Trace:
context_switch kernel/sched/core.c:5030 [inline]
__schedule+0x11b8/0x43b0 kernel/sched/core.c:6376
preempt_schedule_irq+0xb1/0x150 kernel/sched/core.c:6780
irqentry_exit+0x63/0x70 kernel/entry/common.c:432
asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:thp_nr_pages include/linux/huge_mm.h:280 [inline]
RIP: 0010:find_lock_entries+0x586/0xd50 mm/filemap.c:2100
Code: 24 10 42 80 3c 38 00 4c 8b 3c 24 74 08 4c 89 ff e8 5f 1a 1f 00 4d 8b 3f 4c 89 fe 48 83 e6 01 31 ff e8 de aa d9 ff 49 83 e7 01 <4c> 8d a4 24 80 00 00 00 0f 85 66 07 00 00 48 b8 00 00 00 00 00 fc
RSP: 0018:ffffc90002e4f280 EFLAGS: 00000246
RAX: ffffffff819e1712 RBX: 00000000000011e5 RCX: ffff888022a0bb80
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90002e4f3b0 R08: dffffc0000000000 R09: fffff940003d4639
R10: fffff940003d4639 R11: 1ffffd40003d4638 R12: 00000000000011df
R13: 1ffffd40003d4638 R14: ffffea0001ea31c0 R15: 0000000000000000
truncate_inode_pages_range+0x17c/0xef0 mm/truncate.c:320
evict+0x498/0x870 fs/inode.c:649
__dentry_kill+0x431/0x650 fs/dcache.c:586
shrink_dentry_list+0x388/0x680 fs/dcache.c:1181
shrink_dcache_parent+0xa8/0x3a0 fs/dcache.c:-1
do_one_tree+0x23/0xe0 fs/dcache.c:1662
shrink_dcache_for_umount+0x65/0x110 fs/dcache.c:1679
generic_shutdown_super+0x63/0x300 fs/super.c:447
kill_anon_super fs/super.c:1089 [inline]
kill_litter_super+0x72/0xa0 fs/super.c:1098
deactivate_locked_super+0x93/0xf0 fs/super.c:335
cleanup_mnt+0x418/0x4d0 fs/namespace.c:1143
task_work_run+0x125/0x1a0 kernel/task_work.c:188
exit_task_work include/linux/task_work.h:33 [inline]
do_exit+0x616/0x20a0 kernel/exit.c:874
do_group_exit+0x12e/0x300 kernel/exit.c:996
get_signal+0x6ca/0x12c0 kernel/signal.c:2900
arch_do_signal_or_restart+0xc1/0x1300 arch/x86/kernel/signal.c:867
handle_signal_work kernel/entry/common.c:154 [inline]
exit_to_user_mode_loop+0x9e/0x130 kernel/entry/common.c:178
exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:214
__syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline]
syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307
do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f56d7516969
RSP: 002b:00007f56d535d038 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: 0000000001af0000 RBX: 00007f56d773e080 RCX: 00007f56d7516969
RDX: 0000000000000000 RSI: 0000000000000007 RDI: 0000000000000007
RBP: 00007f56d7598ab1 R08: 0000000000000000 R09: 0000000000000000
R10: 0001000000201005 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f56d773e080 R15: 00007ffe9483a808
rcu: rcu_preempt kthread timer wakeup didn't happen for 10520 jiffies! g15245 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: Possible timer handling issue on cpu=1 timer-softirq=9414
rcu: rcu_preempt kthread starved for 10521 jiffies! g15245 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:28032 pid: 15 ppid: 2 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5030 [inline]
__schedule+0x11b8/0x43b0 kernel/sched/core.c:6376
schedule+0x11b/0x1e0 kernel/sched/core.c:6459
schedule_timeout+0x15c/0x280 kernel/time/timer.c:1914
rcu_gp_fqs_loop+0x29e/0x11b0 kernel/rcu/tree.c:1972
rcu_gp_kthread+0x98/0x350 kernel/rcu/tree.c:2145
kthread+0x436/0x520 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
rcu: Stack dump where RCU GP kthread last ran:
NMI backtrace for cpu 1
CPU: 1 PID: 5870 Comm: syz.6.383 Not tainted 5.15.181-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025
Call Trace:
dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106
nmi_cpu_backtrace+0x397/0x3d0 lib/nmi_backtrace.c:111
nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62
trigger_single_cpu_backtrace include/linux/nmi.h:166 [inline]
rcu_check_gp_kthread_starvation+0x1cd/0x250 kernel/rcu/tree_stall.h:487
print_other_cpu_stall+0x10c8/0x1220 kernel/rcu/tree_stall.h:592
check_cpu_stall kernel/rcu/tree_stall.h:745 [inline]
rcu_pending kernel/rcu/tree.c:3932 [inline]
rcu_sched_clock_irq+0x831/0x1110 kernel/rcu/tree.c:2619
update_process_times+0x193/0x200 kernel/time/timer.c:1818
tick_sched_handle kernel/time/tick-sched.c:254 [inline]
tick_sched_timer+0x37d/0x560 kernel/time/tick-sched.c:1473
__run_hrtimer kernel/time/hrtimer.c:1690 [inline]
__hrtimer_run_queues+0x4fe/0xc40 kernel/time/hrtimer.c:1754
hrtimer_interrupt+0x3bb/0x8d0 kernel/time/hrtimer.c:1816
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1097 [inline]
__sysvec_apic_timer_interrupt+0x137/0x4a0 arch/x86/kernel/apic/apic.c:1114
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1108
asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:xrstor_from_user_sigframe arch/x86/include/asm/fpu/internal.h:368 [inline]
RIP: 0010:__restore_fpregs_from_user arch/x86/kernel/fpu/signal.c:231 [inline]
RIP: 0010:restore_fpregs_from_user arch/x86/kernel/fpu/signal.c:259 [inline]
RIP: 0010:__fpu_restore_sig arch/x86/kernel/fpu/signal.c:334 [inline]
RIP: 0010:fpu__restore_sig+0x4c0/0xf50 arch/x86/kernel/fpu/signal.c:466
Code: c6 16 8f 0a 44 23 6c 24 50 80 7c 24 24 00 0f 85 ad 00 00 00 e8 61 f1 4b 00 0f 01 cb 4c 89 e7 48 8b 44 24 40 31 d2 48 0f ae 2f <31> c0 41 89 c4 0f 01 ca 31 ff 44 89 e6 e8 9e f4 4b 00 31 ff 4c 89
RSP: 0018:ffffc90002f7fb40 EFLAGS: 00040246
RAX: 0000000000000007 RBX: 1ffff11003c8be19 RCX: ffff88801e45d940
RDX: 0000000000000000 RSI: 0000000000000200 RDI: 00007ffc65eab940
RBP: ffffc90002f7fcf0 R08: 0000000000000000 R09: fffff520005eff90
R10: fffff520005eff90 R11: 1ffff920005eff8a R12: 00007ffc65eab940
R13: 0000000000000000 R14: ffff88801e45d940 R15: dffffc0000000000
restore_sigcontext arch/x86/kernel/signal.c:139 [inline]
__ia32_sys_rt_sigreturn+0x649/0x790 arch/x86/kernel/signal.c:674
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f552ec6f969
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:00007ffc65eabd38 EFLAGS: 00000246
RAX: fffffffffffffffc RBX: 000000000002f1e8 RCX: 00007f552ec6f969
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f552ee96fac
RBP: 0000000000000032 R08: 0001c49f816e825e R09: 0000000965eac02f
R10: 00007ffc65eabe30 R11: 0000000000000246 R12: 00007f552ee96fac
R13: 00007ffc65eabe30 R14: 000000000002f21a R15: 00007ffc65eabe50