rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P18332/1:b..l P19616/1:b..l P19634/1:b..l rcu: (detected by 0, t=10502 jiffies, g=97345, q=353 ncpus=2) task:syz.0.3661 state:R running task stack:27544 pid:19634 tgid:19628 ppid:17185 task_flags:0x40044c 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:lock_release+0x183/0x2d0 kernel/locking/lockdep.c:5893 Code: 0f c1 05 b8 00 19 12 83 f8 01 0f 85 03 01 00 00 9c 58 f6 c4 02 0f 85 ee 00 00 00 41 f7 c5 00 02 00 00 74 01 fb 48 8b 44 24 10 <65> 48 2b 05 4d b9 18 12 0f 85 32 01 00 00 48 83 c4 18 5b 41 5c 41 RSP: 0018:ffffc9000bb4f198 EFLAGS: 00000206 RAX: 14857b56d4c62400 RBX: ffffffff8e3c96a0 RCX: ffffc9000bb4f1a4 RDX: 0000000000000001 RSI: ffffffff8daa8a1d RDI: ffffffff8bf2b400 RBP: 0000000000000001 R08: 0000000000000001 R09: 000000002d64dbdc R10: 0000000000000002 R11: 000000000000fca1 R12: ffffffff816cb9a4 R13: 0000000000000206 R14: ffff88802a40c980 R15: 0000000000000002 rcu_lock_release include/linux/rcupdate.h:341 [inline] rcu_read_unlock include/linux/rcupdate.h:897 [inline] class_rcu_destructor include/linux/rcupdate.h:1195 [inline] unwind_next_frame+0x3f9/0x20b0 arch/x86/kernel/unwind_orc.c:495 arch_stack_walk+0x94/0x100 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122 save_stack+0x160/0x1f0 mm/page_owner.c:165 __reset_page_owner+0x84/0x1a0 mm/page_owner.c:320 reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1406 [inline] free_unref_folios+0xa22/0x1610 mm/page_alloc.c:3000 folios_put_refs+0x4be/0x750 mm/swap.c:1002 free_pages_and_swap_cache+0x3f0/0x4a0 mm/swap_state.c:358 __tlb_batch_free_encoded_pages+0xf9/0x290 mm/mmu_gather.c:136 tlb_batch_pages_flush mm/mmu_gather.c:149 [inline] tlb_flush_mmu_free mm/mmu_gather.c:397 [inline] tlb_flush_mmu mm/mmu_gather.c:404 [inline] tlb_finish_mmu+0x168/0x7c0 mm/mmu_gather.c:497 exit_mmap+0x3f9/0xb60 mm/mmap.c:1290 __mmput+0x12a/0x410 kernel/fork.c:1173 mmput+0x62/0x70 kernel/fork.c:1196 exit_mm kernel/exit.c:581 [inline] do_exit+0x7d7/0x2bd0 kernel/exit.c:959 do_group_exit+0xd3/0x2a0 kernel/exit.c:1112 get_signal+0x2671/0x26d0 kernel/signal.c:3034 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+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: 0033:0x7f3680f8f749 RSP: 002b:00007f3681de70e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00007f36811e6188 RCX: 00007f3680f8f749 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f36811e6188 RBP: 00007f36811e6180 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f36811e6218 R14: 00007ffc56670010 R15: 00007ffc566700f8 task:syz.0.3656 state:R running task stack:23624 pid:19616 tgid:19616 ppid:17185 task_flags:0x400640 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_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:rcu_lock_acquire include/linux/rcupdate.h:331 [inline] RIP: 0010:rcu_read_lock include/linux/rcupdate.h:867 [inline] RIP: 0010:mt_find+0x12c/0xa20 lib/maple_tree.c:6495 Code: 08 00 00 49 8b 5d 00 4c 8b 74 24 08 48 89 df 4c 89 f6 e8 c7 e7 4c f6 49 39 de 0f 82 3a 06 00 00 e8 a9 ed 4c f6 e8 94 02 31 f6 <45> 31 c9 45 31 c0 b9 02 00 00 00 48 8d 05 00 00 00 00 50 31 d2 31 RSP: 0018:ffffc90003b8ed30 EFLAGS: 00000293 RAX: 0000000000000001 RBX: 000000110d355000 RCX: ffffffff8b71fb79 RDX: 0000000000000000 RSI: ffffffff8b71fb87 RDI: ffff8880320d4e04 RBP: 1ffff92000771dca R08: 0000000000000006 R09: 000000110d355000 R10: ffffffffffffffff R11: ffff8880320d54b0 R12: 0000000000000001 R13: ffffc90003b8ee70 R14: ffffffffffffffff R15: 0000000000000000 find_vma+0xbf/0x140 mm/mmap.c:906 gup_vma_lookup+0x24/0x220 mm/gup.c:1275 __get_user_pages+0x241/0x3590 mm/gup.c:1396 __get_user_pages_locked mm/gup.c:1692 [inline] get_dump_page+0x257/0x3d0 mm/gup.c:2192 dump_user_range+0x195/0xb70 fs/coredump.c:1366 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: 0033:0x7f3680f8f751 RSP: 002b:fffffffffffffe70 EFLAGS: 00010217 RAX: 0000000000000000 RBX: 00007f36811e5fa0 RCX: 00007f3680f8f749 RDX: 0000000000000000 RSI: fffffffffffffe70 RDI: 0000000000008000 RBP: 00007f3681013f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 00007f36811e6038 R14: 00007f36811e5fa0 R15: 00007ffc566700f8 task:syz-executor state:R running task stack:23992 pid:18332 tgid:18332 ppid:18327 task_flags:0x400140 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:lock_release+0x183/0x2d0 kernel/locking/lockdep.c:5893 Code: 0f c1 05 b8 00 19 12 83 f8 01 0f 85 03 01 00 00 9c 58 f6 c4 02 0f 85 ee 00 00 00 41 f7 c5 00 02 00 00 74 01 fb 48 8b 44 24 10 <65> 48 2b 05 4d b9 18 12 0f 85 32 01 00 00 48 83 c4 18 5b 41 5c 41 RSP: 0000:ffffc90003597270 EFLAGS: 00000206 RAX: 356a1df391329700 RBX: ffffffff8e3c96a0 RCX: ffffc9000359727c RDX: 0000000000000001 RSI: ffffffff8daa8a1d RDI: ffffffff8bf2b400 RBP: 0000000000000001 R08: 0000000000000001 R09: 00000000dbd4d8a6 R10: 0000000000000002 R11: 00000000000a782f R12: ffffffff816cb9a4 R13: 0000000000000206 R14: ffff88802e88c980 R15: 0000000000000002 rcu_lock_release include/linux/rcupdate.h:341 [inline] rcu_read_unlock include/linux/rcupdate.h:897 [inline] class_rcu_destructor include/linux/rcupdate.h:1195 [inline] unwind_next_frame+0x3f9/0x20b0 arch/x86/kernel/unwind_orc.c:495 arch_stack_walk+0x94/0x100 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122 save_stack+0x160/0x1f0 mm/page_owner.c:165 __set_page_owner+0x91/0x560 mm/page_owner.c:341 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1af/0x220 mm/page_alloc.c:1857 prep_new_page mm/page_alloc.c:1865 [inline] get_page_from_freelist+0xd0b/0x31a0 mm/page_alloc.c:3915 __alloc_frozen_pages_noprof+0x25f/0x2430 mm/page_alloc.c:5210 alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2486 folio_alloc_mpol_noprof+0x36/0x2f0 mm/mempolicy.c:2505 vma_alloc_folio_noprof+0xed/0x1e0 mm/mempolicy.c:2540 folio_prealloc mm/memory.c:1193 [inline] wp_page_copy mm/memory.c:3719 [inline] do_wp_page+0x202f/0x5010 mm/memory.c:4180 handle_pte_fault mm/memory.c:6289 [inline] __handle_mm_fault+0x1bd2/0x2bb0 mm/memory.c:6411 handle_mm_fault+0x3fe/0xad0 mm/memory.c:6580 do_user_addr_fault+0x60c/0x1370 arch/x86/mm/fault.c:1336 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: 0033:0x7fc4c03452f9 RSP: 002b:00007ffc356b0448 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007fc4c0385e93 RDX: 00000000000000d7 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000001 R10: 000055556f9117d0 R11: 0000000000000246 R12: 00000000000000d7 R13: ffffffffffffffa8 R14: 0000000000000006 R15: 00007ffc356b05e0 rcu: rcu_preempt kthread starved for 10435 jiffies! g97345 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:28320 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: CPU: 0 UID: 0 PID: 0 Comm: swapper/0 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:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:82 Code: a6 5f 02 c3 cc cc cc cc 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 13 19 12 00 fb f4 cc 35 03 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90 RSP: 0018:ffffffff8e007df8 EFLAGS: 000002c6 RAX: 0000000006e4ace5 RBX: 0000000000000000 RCX: ffffffff8b7846d9 RDX: 0000000000000000 RSI: ffffffff8daceab2 RDI: ffffffff8bf2b400 RBP: fffffbfff1c12f68 R08: 0000000000000001 R09: ffffed101708673d R10: ffff8880b84339eb R11: ffffffff8e098670 R12: 0000000000000000 R13: ffffffff8e097b40 R14: ffffffff9088bdd0 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8881248f5000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f8d5435f7ad CR3: 000000002abfa000 CR4: 00000000003526f0 Call Trace: arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:767 default_idle_call+0x6c/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:191 [inline] do_idle+0x38d/0x510 kernel/sched/idle.c:332 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:430 rest_init+0x16b/0x2b0 init/main.c:757 start_kernel+0x3ef/0x4d0 init/main.c:1206 x86_64_start_reservations+0x18/0x30 arch/x86/kernel/head64.c:310 x86_64_start_kernel+0x130/0x190 arch/x86/kernel/head64.c:291 common_startup_64+0x13e/0x148