rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5160/1:b..l P5159/1:b..l
(detected by 0, t=10502 jiffies, g=9189, q=45)
task:syz.1.212 state:R running task stack:27952 pid: 5159 ppid: 4185 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:5049 [inline]
__schedule+0x11ef/0x43c0 kernel/sched/core.c:6395
preempt_schedule_irq+0xbb/0x160 kernel/sched/core.c:6799
irqentry_exit+0x63/0x70 kernel/entry/common.c:432
asm_sysvec_reschedule_ipi+0x16/0x20 arch/x86/include/asm/idtentry.h:681
RIP: 0010:lock_is_held_type+0x13a/0x190 kernel/locking/lockdep.c:5671
Code: 75 40 48 c7 04 24 00 00 00 00 9c 8f 04 24 f7 04 24 00 02 00 00 75 46 41 f7 c5 00 02 00 00 74 01 fb 65 48 8b 04 25 28 00 00 00 <48> 3b 44 24 08 75 3c 89 e8 48 83 c4 10 5b 41 5c 41 5d 41 5e 41 5f
RSP: 0018:ffffc900033cfba8 EFLAGS: 00000206
RAX: e6d442c258e50500 RBX: ffff88801ea05940 RCX: e6d442c258e50500
RDX: 0000000000000000 RSI: ffffffff8a2b3aa0 RDI: ffffffff8a79fe40
RBP: 0000000000000000 R08: dffffc0000000000 R09: 1ffffffff203aa18
R10: dffffc0000000000 R11: fffffbfff203aa19 R12: 0000000000000001
R13: 0000000000000246 R14: ffffffff8c344408 R15: ffff88801ea06458
lock_is_held include/linux/lockdep.h:287 [inline]
task_css include/linux/cgroup.h:496 [inline]
mem_cgroup_from_task+0x5e/0x110 mm/memcontrol.c:935
get_obj_cgroup_from_current+0x146/0x2f0 mm/memcontrol.c:2926
memcg_slab_pre_alloc_hook mm/slab.h:283 [inline]
slab_pre_alloc_hook+0x7e/0xc0 mm/slab.h:497
slab_alloc_node mm/slub.c:3139 [inline]
slab_alloc mm/slub.c:3233 [inline]
kmem_cache_alloc+0x3d/0x290 mm/slub.c:3238
kmem_cache_zalloc include/linux/slab.h:728 [inline]
__alloc_file+0x25/0x240 fs/file_table.c:132
alloc_empty_file+0x90/0x180 fs/file_table.c:181
alloc_file+0x5b/0x4f0 fs/file_table.c:223
alloc_file_clone+0x23/0xa0 fs/file_table.c:275
create_pipe_files+0x420/0x700 fs/pipe.c:944
__do_pipe_flags+0x46/0x1f0 fs/pipe.c:966
do_pipe2+0xa7/0x190 fs/pipe.c:1014
__do_sys_pipe fs/pipe.c:1037 [inline]
__se_sys_pipe fs/pipe.c:1035 [inline]
__x64_sys_pipe+0x36/0x40 fs/pipe.c:1035
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: 0033:0x7f2db9daf819
RSP: 002b:00007f2db8009028 EFLAGS: 00000246 ORIG_RAX: 0000000000000016
RAX: ffffffffffffffda RBX: 00007f2dba028fa0 RCX: 00007f2db9daf819
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000200000000000
RBP: 00007f2db9e45c91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f2dba029038 R14: 00007f2dba028fa0 R15: 00007ffdf05c27f8
task:syz.4.213 state:R running task stack:26320 pid: 5160 ppid: 4197 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5049 [inline]
__schedule+0x11ef/0x43c0 kernel/sched/core.c:6395
preempt_schedule_notrace+0xd9/0x120 kernel/sched/core.c:6650
preempt_schedule_notrace_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:35
rcu_is_watching+0x72/0xa0 kernel/rcu/tree.c:1124
rcu_read_lock include/linux/rcupdate.h:741 [inline]
percpu_ref_put_many include/linux/percpu-refcount.h:317 [inline]
percpu_ref_put+0x24/0x150 include/linux/percpu-refcount.h:338
css_put include/linux/cgroup.h:405 [inline]
__mem_cgroup_charge+0x52/0x80 mm/memcontrol.c:6802
mem_cgroup_charge include/linux/memcontrol.h:700 [inline]
wp_page_copy+0x4ce/0x2050 mm/memory.c:3078
handle_pte_fault mm/memory.c:4668 [inline]
__handle_mm_fault mm/memory.c:4785 [inline]
handle_mm_fault+0x1f06/0x4410 mm/memory.c:4883
do_user_addr_fault+0x489/0xc80 arch/x86/mm/fault.c:1355
handle_page_fault arch/x86/mm/fault.c:1443 [inline]
exc_page_fault+0x60/0x100 arch/x86/mm/fault.c:1496
asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:606
RIP: 0033:0x7fd9fa1e6760
RSP: 002b:00007fffcdcefed0 EFLAGS: 00010207
RAX: 0000000000000001 RBX: 0000000000000000 RCX: 00007fd9fa319819
RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007fd9fa592fa8
RBP: 0000000000001e33 R08: 00007fffcdcefd67 R09: 0000000000000000
R10: 00007fd9fa592fa0 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fd9fa592fac R14: 00007fd9fa592fa8 R15: 00007fd9fa592fa0
rcu: rcu_preempt kthread starved for 10551 jiffies! g9189 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:27536 pid: 15 ppid: 2 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5049 [inline]
__schedule+0x11ef/0x43c0 kernel/sched/core.c:6395
schedule+0x11b/0x1e0 kernel/sched/core.c:6478
schedule_timeout+0x184/0x2d0 kernel/time/timer.c:2117
rcu_gp_fqs_loop+0x2be/0x11d0 kernel/rcu/tree.c:1972
rcu_gp_kthread+0x9b/0x370 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 0
CPU: 0 PID: 5161 Comm: syz.1.212 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
Call Trace:
dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106
nmi_cpu_backtrace+0x3a2/0x3d0 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+0x1110/0x1270 kernel/rcu/tree_stall.h:592
check_cpu_stall kernel/rcu/tree_stall.h:745 [inline]
rcu_pending kernel/rcu/tree.c:3936 [inline]
rcu_sched_clock_irq+0x843/0x1120 kernel/rcu/tree.c:2619
update_process_times+0x193/0x200 kernel/time/timer.c:2021
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:1685 [inline]
__hrtimer_run_queues+0x4b4/0xb70 kernel/time/hrtimer.c:1749
hrtimer_interrupt+0x3bb/0x8d0 kernel/time/hrtimer.c:1811
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:pagefault_disabled_inc include/linux/uaccess.h:219 [inline]
RIP: 0010:pagefault_disable include/linux/uaccess.h:236 [inline]
RIP: 0010:restore_fpregs_from_user arch/x86/kernel/fpu/signal.c:258 [inline]
RIP: 0010:__fpu_restore_sig arch/x86/kernel/fpu/signal.c:334 [inline]
RIP: 0010:fpu__restore_sig+0x503/0x1060 arch/x86/kernel/fpu/signal.c:466
Code: 48 c1 eb 03 4c 89 e8 48 c1 e8 03 48 89 44 24 50 48 c7 c0 70 33 e3 8b 48 c1 e8 03 48 89 44 24 48 e8 22 0e 00 00 42 0f b6 04 23 <84> c0 0f 85 cf 01 00 00 48 8b 44 24 20 ff 00 0f 1f 44 00 00 e8 24
RSP: 0018:ffffc900033efb40 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 1ffff110046566a9 RCX: ffffffff962dbf00
RDX: ffffc9000ef8c000 RSI: 0000000000000200 RDI: ffffffff812c544e
RBP: ffffc900033efcf0 R08: 0000000000000000 R09: 1ffff9200067df8f
R10: dffffc0000000000 R11: fffff5200067df90 R12: dffffc0000000000
R13: ffff8880232b1dc0 R14: 00007f2db7fe7d00 R15: 1ffff9200067df74
restore_sigcontext arch/x86/kernel/signal.c:139 [inline]
__ia32_sys_rt_sigreturn+0x5e4/0x760 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: 0033:0x7f2db9daf817
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:00007f2db7fe80e8 EFLAGS: 00000246
RAX: 00000000000000ca RBX: 00007f2dba029098 RCX: 00007f2db9daf819
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f2dba029098
RBP: 00007f2dba029090 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f2dba029128 R14: 00007ffdf05c2710 R15: 00007ffdf05c27f8