rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P789/1:b..l P5828/1:b..l P8620/1:b..l rcu: (detected by 1, t=10503 jiffies, g=24365, q=1108 ncpus=2) task:syz.0.627 state:R running task stack:24312 pid:8620 tgid:8618 ppid:5828 task_flags:0x400840 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x1139/0x6150 kernel/sched/core.c:6863 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7190 irqentry_exit+0x1d8/0x8c0 kernel/entry/common.c:216 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:rcu_preempt_read_exit kernel/rcu/tree_plugin.h:398 [inline] RIP: 0010:__rcu_read_unlock+0x63/0x5a0 kernel/rcu/tree_plugin.h:435 Code: 7c 08 84 d2 0f 85 45 02 00 00 65 4c 8b 25 ad 6f 0e 12 49 8d bc 24 84 04 00 00 8b 9d 84 04 00 00 48 b8 00 00 00 00 00 fc ff df <48> 89 fa 48 c1 ea 03 83 eb 01 0f b6 14 02 48 89 f8 83 e0 07 83 c0 RSP: 0018:ffffc9000e676e58 EFLAGS: 00000246 RAX: dffffc0000000000 RBX: 0000000000000001 RCX: ffffc9000e676e44 RDX: 0000000000000000 RSI: ffffffff8daa7ea1 RDI: ffff888049438484 RBP: ffff888049438000 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000001 R11: ffff888049438b30 R12: ffff888049438000 R13: ffffed102808c338 R14: dffffc0000000000 R15: ffff88814bde1800 rcu_read_unlock include/linux/rcupdate.h:899 [inline] shrink_slab_memcg mm/shrinker.c:525 [inline] shrink_slab+0x78a/0x12b0 mm/shrinker.c:628 shrink_node_memcgs mm/vmscan.c:6022 [inline] shrink_node+0x918/0x3bb0 mm/vmscan.c:6061 shrink_zones mm/vmscan.c:6300 [inline] do_try_to_free_pages+0x362/0x1920 mm/vmscan.c:6362 try_to_free_mem_cgroup_pages+0x31b/0x740 mm/vmscan.c:6690 try_charge_memcg+0x42a/0xd30 mm/memcontrol.c:2388 obj_cgroup_charge_pages mm/memcontrol.c:2823 [inline] __memcg_kmem_charge_page+0xda/0x420 mm/memcontrol.c:2867 __alloc_frozen_pages_noprof+0x323/0x2430 mm/page_alloc.c:5227 alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2486 alloc_frozen_pages_noprof mm/mempolicy.c:2557 [inline] alloc_pages_noprof+0x131/0x390 mm/mempolicy.c:2577 pagetable_alloc_noprof include/linux/mm.h:3190 [inline] __pte_alloc_one_noprof include/asm-generic/pgalloc.h:76 [inline] pte_alloc_one+0x1e/0x3d0 arch/x86/mm/pgtable.c:18 do_fault_around mm/memory.c:5707 [inline] do_read_fault mm/memory.c:5746 [inline] do_fault+0x8b8/0x1ad0 mm/memory.c:5889 do_pte_missing mm/memory.c:4401 [inline] handle_pte_fault mm/memory.c:6273 [inline] __handle_mm_fault+0x1919/0x2bb0 mm/memory.c:6411 handle_mm_fault+0x3fe/0xad0 mm/memory.c:6580 faultin_page mm/gup.c:1126 [inline] __get_user_pages+0x54e/0x3590 mm/gup.c:1428 populate_vma_page_range+0x267/0x3f0 mm/gup.c:1860 __mm_populate+0x1d8/0x380 mm/gup.c:1963 mm_populate include/linux/mm.h:3701 [inline] vm_mmap_pgoff+0x37f/0x470 mm/util.c:586 ksys_mmap_pgoff+0x7d/0x5c0 mm/mmap.c:604 __do_sys_mmap arch/x86/kernel/sys_x86_64.c:89 [inline] __se_sys_mmap arch/x86/kernel/sys_x86_64.c:82 [inline] __x64_sys_mmap+0x125/0x190 arch/x86/kernel/sys_x86_64.c:82 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f765e18f749 RSP: 002b:00007f765ef81038 EFLAGS: 00000246 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 00007f765e3e6090 RCX: 00007f765e18f749 RDX: b635773f06ebbeee RSI: 0000000000b36000 RDI: 0000200000000000 RBP: 00007f765e213f91 R08: ffffffffffffffff R09: 0000000000000000 R10: 0000000000008031 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f765e3e6128 R14: 00007f765e3e6090 R15: 00007ffc3f613ce8 task:syz-executor state:R running task stack:23640 pid:5828 tgid:5828 ppid:1 task_flags:0x400940 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x1139/0x6150 kernel/sched/core.c:6863 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7190 irqentry_exit+0x1d8/0x8c0 kernel/entry/common.c:216 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:lock_acquire+0x62/0x330 kernel/locking/lockdep.c:5872 Code: b4 18 12 83 f8 07 0f 87 a2 02 00 00 89 c0 48 0f a3 05 72 b9 ee 0e 0f 82 74 02 00 00 8b 35 0a ea ee 0e 85 f6 0f 85 8d 00 00 00 <48> 8b 44 24 30 65 48 2b 05 89 b4 18 12 0f 85 ad 02 00 00 48 83 c4 RSP: 0018:ffffc900033669b8 EFLAGS: 00000206 RAX: 0000000000000046 RBX: ffffffff8e3c96a0 RCX: 0000000013d622c6 RDX: 0000000000000000 RSI: ffffffff8daa7ea1 RDI: ffffffff8bf2b400 RBP: 0000000000000002 R08: 00000000accd7842 R09: 000000002accd784 R10: 0000000000000002 R11: ffff8880266cd4b0 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:867 [inline] shrink_slab_memcg mm/shrinker.c:536 [inline] shrink_slab+0x897/0x12b0 mm/shrinker.c:628 shrink_node_memcgs mm/vmscan.c:6022 [inline] shrink_node+0x918/0x3bb0 mm/vmscan.c:6061 shrink_zones mm/vmscan.c:6300 [inline] do_try_to_free_pages+0x362/0x1920 mm/vmscan.c:6362 try_to_free_mem_cgroup_pages+0x31b/0x740 mm/vmscan.c:6690 try_charge_memcg+0x42a/0xd30 mm/memcontrol.c:2388 try_charge mm/memcontrol.c:2530 [inline] charge_memcg+0x8a/0x230 mm/memcontrol.c:4728 mem_cgroup_swapin_charge_folio+0xeb/0x470 mm/memcontrol.c:4814 __read_swap_cache_async+0x397/0x500 mm/swap_state.c:481 swap_cluster_readahead+0x432/0x770 mm/swap_state.c:646 swapin_readahead+0x160/0x1220 mm/swap_state.c:821 do_swap_page+0x962/0x64a0 mm/memory.c:4753 handle_pte_fault mm/memory.c:6276 [inline] __handle_mm_fault+0x19cb/0x2bb0 mm/memory.c:6411 handle_mm_fault+0x3fe/0xad0 mm/memory.c:6580 do_user_addr_fault+0x7a6/0x1370 arch/x86/mm/fault.c:1387 handle_page_fault arch/x86/mm/fault.c:1476 [inline] exc_page_fault+0x64/0xc0 arch/x86/mm/fault.c:1532 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618 RIP: 0010:rep_stos_alternative+0x40/0x80 arch/x86/lib/clear_page_64.S:99 Code: c9 75 f6 e9 d2 8d 04 00 48 89 07 48 83 c7 08 83 e9 08 74 ef 83 f9 08 73 ef eb de 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 <48> 89 07 48 89 47 08 48 89 47 10 48 89 47 18 48 89 47 20 48 89 47 RSP: 0018:ffffc90003367ad8 EFLAGS: 00050246 RAX: 0000000000000000 RBX: 0000000000000040 RCX: 0000000000000040 RDX: ffff8880266cc980 RSI: ffffffff8162ad8e RDI: 00007ffc3f6136c0 RBP: 0000000000000000 R08: 00000000ffffffff R09: 00000000ffffffff R10: 0000000000000001 R11: ffff8880266cd4b0 R12: 00007ffc3f6134c0 R13: ffff8880266ce380 R14: 00007ffc3f6134c0 R15: 00007ffffffff000 __clear_user arch/x86/include/asm/uaccess_64.h:188 [inline] copy_fpstate_to_sigframe+0x178/0xad0 arch/x86/kernel/fpu/signal.c:203 get_sigframe+0x4a8/0x9c0 arch/x86/kernel/signal.c:163 x64_setup_rt_frame+0x129/0xcf0 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+0x5da/0x7e0 arch/x86/kernel/signal.c:339 __exit_to_user_mode_loop kernel/entry/common.c:41 [inline] exit_to_user_mode_loop+0x8c/0x540 kernel/entry/common.c:75 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline] do_syscall_64+0x4ee/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f765e1c2005 RSP: 002b:00007ffc3f614000 EFLAGS: 00000293 ORIG_RAX: 00000000000000e6 RAX: 0000000000000000 RBX: 00000000000001de RCX: 00007f765e1c2005 RDX: 00007ffc3f614040 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007ffc3f6140ac R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000001388 R13: 00000000000927c0 R14: 000000000003eeeb R15: 00007ffc3f614100 task:kworker/0:2 state:R running task stack:24904 pid:789 tgid:789 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: events_power_efficient gc_worker Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x1139/0x6150 kernel/sched/core.c:6863 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7190 irqentry_exit+0x1d8/0x8c0 kernel/entry/common.c:216 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:__seqprop_spinlock_sequence include/linux/seqlock.h:227 [inline] RIP: 0010:nf_conntrack_get_ht include/net/netfilter/nf_conntrack.h:342 [inline] RIP: 0010:gc_worker+0x2d5/0x16e0 net/netfilter/nf_conntrack_core.c:1548 Code: 00 00 48 c7 c7 a8 61 89 90 e8 37 ee 05 f8 9c 5b 81 e3 00 02 00 00 31 ff 48 89 de e8 c5 da 2a f8 58 48 85 db 0f 85 d4 0f 00 00 e6 df 2a f8 8b 1d 10 5b f5 06 41 89 dc 31 ff 41 83 e4 01 44 89 RSP: 0018:ffffc90003637ad8 EFLAGS: 00000293 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff899411c9 RDX: ffff888025bfa4c0 RSI: ffffffff899411d8 RDI: 0000000000000007 RBP: ffffffff9b0a38ac R08: 0000000000000007 R09: 0000000000000000 R10: 0000000000000000 R11: ffff888025bfaff0 R12: ffff888025200000 R13: 0000000000040000 R14: dffffc0000000000 R15: 0000000000001945 process_one_work+0x9ba/0x1b20 kernel/workqueue.c:3257 process_scheduled_works kernel/workqueue.c:3340 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3421 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 rcu: rcu_preempt kthread starved for 10649 jiffies! g24365 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:28424 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x1139/0x6150 kernel/sched/core.c:6863 __schedule_loop kernel/sched/core.c:6945 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6960 schedule_timeout+0x123/0x290 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x1ea/0xaf0 kernel/rcu/tree.c:2083 rcu_gp_kthread+0x26d/0x380 kernel/rcu/tree.c:2285 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x983/0xb10 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: 8634 Comm: syz.0.627 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:check_kcov_mode kernel/kcov.c:183 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x31/0x70 kernel/kcov.c:217 Code: 24 65 48 8b 15 98 c9 f3 11 65 8b 05 a9 c9 f3 11 a9 00 01 ff 00 74 1d f6 c4 01 74 43 a9 00 00 0f 00 75 3c a9 00 00 f0 00 75 35 <8b> 82 6c 16 00 00 85 c0 74 2b 8b 82 48 16 00 00 83 f8 02 75 20 48 RSP: 0018:ffffc90000007b70 EFLAGS: 00000246 RAX: 0000000080000101 RBX: ffffc9001d128990 RCX: ffffffff897edf4d RDX: ffff88804e1aa4c0 RSI: ffffffff897edf57 RDI: 0000000000000007 RBP: ffff8880785fdac0 R08: 0000000000000007 R09: 0000000000000000 R10: 0000000000000000 R11: ffff88804e1aaff0 R12: 0000000000000000 R13: 0000000000000000 R14: fffffff0a3da8872 R15: 0000000000000000 FS: 00007f765ef606c0(0000) GS:ffff8881248f5000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f9f2e9e7dac CR3: 000000003f6f2000 CR4: 00000000003526f0 Call Trace: pie_calculate_probability+0x397/0x850 net/sched/sch_pie.c:402 fq_pie_timer+0x21e/0x5b0 net/sched/sch_fq_pie.c:402 call_timer_fn+0x19a/0x5a0 kernel/time/timer.c:1748 expire_timers kernel/time/timer.c:1799 [inline] __run_timers+0x74a/0xae0 kernel/time/timer.c:2373 __run_timer_base kernel/time/timer.c:2385 [inline] __run_timer_base kernel/time/timer.c:2377 [inline] run_timer_base+0x114/0x190 kernel/time/timer.c:2394 run_timer_softirq+0x1a/0x40 kernel/time/timer.c:2404 handle_softirqs+0x219/0x950 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0x109/0x170 kernel/softirq.c:723 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline] sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1056 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:get_current arch/x86/include/asm/current.h:25 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x8/0x70 kernel/kcov.c:216 Code: e9 4d 1b 5e 00 be 03 00 00 00 5b e9 72 df ed 02 66 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 8b 34 24 <65> 48 8b 15 98 c9 f3 11 65 8b 05 a9 c9 f3 11 a9 00 01 ff 00 74 1d RSP: 0018:ffffc9000e736440 EFLAGS: 00000202 RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffffffff8201d05a RDX: ffff88804e1aa4c0 RSI: ffffffff8201cdd7 RDI: 0000000000000001 RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000001 R11: ffff88804e1aaff0 R12: 0000000000000000 R13: 0000000000000001 R14: ffff88801cb13b00 R15: ffff888034be8000 trace_mm_shrink_slab_end include/trace/events/vmscan.h:244 [inline] do_shrink_slab+0x637/0x1130 mm/shrinker.c:464 shrink_slab_memcg mm/shrinker.c:550 [inline] shrink_slab+0xa1f/0x12b0 mm/shrinker.c:628 shrink_node_memcgs mm/vmscan.c:6022 [inline] shrink_node+0x918/0x3bb0 mm/vmscan.c:6061 shrink_zones mm/vmscan.c:6300 [inline] do_try_to_free_pages+0x362/0x1920 mm/vmscan.c:6362 try_to_free_mem_cgroup_pages+0x31b/0x740 mm/vmscan.c:6690 try_charge_memcg+0x42a/0xd30 mm/memcontrol.c:2388 try_charge mm/memcontrol.c:2530 [inline] charge_memcg+0x8a/0x230 mm/memcontrol.c:4728 __mem_cgroup_charge+0x2b/0x1e0 mm/memcontrol.c:4745 mem_cgroup_charge include/linux/memcontrol.h:663 [inline] shmem_alloc_and_add_folio+0x50c/0xc20 mm/shmem.c:1942 shmem_get_folio_gfp+0x67f/0x1610 mm/shmem.c:2556 shmem_get_folio mm/shmem.c:2662 [inline] shmem_write_begin+0x1a4/0x3b0 mm/shmem.c:3315 generic_perform_write+0x3c4/0x900 mm/filemap.c:4314 shmem_file_write_iter+0x10e/0x140 mm/shmem.c:3490 __kernel_write_iter+0x31a/0xb10 fs/read_write.c:619 dump_emit_page fs/coredump.c:1298 [inline] dump_user_range+0x413/0xb70 fs/coredump.c:1372 elf_core_dump+0x29c3/0x3c10 fs/binfmt_elf.c:2111 coredump_write fs/coredump.c:1049 [inline] do_coredump fs/coredump.c:1126 [inline] vfs_coredump+0x2b85/0x55e0 fs/coredump.c:1200 get_signal+0x22e1/0x26d0 kernel/signal.c:3019 arch_do_signal_or_restart+0x8f/0x7e0 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+0x38a/0x8c0 kernel/entry/common.c:196 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618 RIP: 0033:0x7f765e18f751 Code: 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 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f RSP: 002b:fffffffffffffe70 EFLAGS: 00010217 RAX: 0000000000000000 RBX: 00007f765e3e6180 RCX: 00007f765e18f749 RDX: 0000000000000000 RSI: fffffffffffffe70 RDI: 0000000000008000 RBP: 00007f765e213f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 00007f765e3e6218 R14: 00007f765e3e6180 R15: 00007ffc3f613ce8