rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P7292/1:b..l rcu: (detected by 1, t=10578 jiffies, g=27177, q=787 ncpus=2) task:syz.5.322 state:R running task stack:19624 pid:7292 tgid:7292 ppid:6018 task_flags:0x400e40 flags:0x0008000b Call Trace: context_switch kernel/sched/core.c:5526 [inline] __schedule+0x1259/0x6920 kernel/sched/core.c:7277 preempt_schedule_irq+0x4e/0x90 kernel/sched/core.c:7599 irqentry_exit_to_kernel_mode_preempt include/linux/irq-entry-common.h:468 [inline] irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:539 [inline] irqentry_exit+0x205/0xa10 kernel/entry/common.c:167 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 RIP: 0010:rcu_is_watching+0x0/0xc0 kernel/rcu/tree.c:749 Code: 5b c3 cc cc cc cc 90 0f 0b 90 5b c3 cc cc cc cc e8 35 93 8f 00 eb cd 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 55 53 65 48 ff 05 8a a0 9c 12 e8 4d 2a e1 09 48 c7 c3 RSP: 0018:ffffc9000450da58 EFLAGS: 00000297 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000002 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8edec4a0 RBP: ffffffff8edec4a0 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000014c03c9 R11: 00000000000164e7 R12: 0000000000000002 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 trace_lock_acquire include/trace/events/lock.h:23 [inline] lock_acquire+0x31e/0x380 kernel/locking/lockdep.c:5905 rcu_lock_acquire include/linux/rcupdate.h:309 [inline] rcu_read_lock include/linux/rcupdate.h:849 [inline] __update_page_owner_free_handle.isra.0+0x4b/0x4b0 mm/page_owner.c:301 __reset_page_owner+0x93/0x190 mm/page_owner.c:339 reset_page_owner include/linux/page_owner.h:26 [inline] __free_pages_prepare mm/page_alloc.c:1418 [inline] free_unref_folios+0xa4a/0x1790 mm/page_alloc.c:3022 shrink_folio_list+0x2f38/0x5e40 mm/vmscan.c:1580 shrink_inactive_list mm/vmscan.c:2027 [inline] shrink_list mm/vmscan.c:2223 [inline] shrink_lruvec+0x130c/0x2670 mm/vmscan.c:6018 shrink_node_memcgs mm/vmscan.c:6220 [inline] shrink_node+0x7a0/0x4320 mm/vmscan.c:6264 shrink_zones mm/vmscan.c:6503 [inline] do_try_to_free_pages+0x33e/0x16d0 mm/vmscan.c:6565 try_to_free_mem_cgroup_pages+0x2bf/0x840 mm/vmscan.c:6887 try_charge_memcg+0x50b/0xf60 mm/memcontrol.c:2718 charge_memcg+0x1ae/0x210 mm/memcontrol.c:5210 __mem_cgroup_charge+0x2b/0x1c0 mm/memcontrol.c:5227 mem_cgroup_charge include/linux/memcontrol.h:662 [inline] shmem_alloc_and_add_folio+0x451/0xd40 mm/shmem.c:1985 shmem_get_folio_gfp+0x75b/0x1980 mm/shmem.c:2528 shmem_fault+0x1fb/0xa30 mm/shmem.c:2729 __do_fault+0x10b/0x440 mm/memory.c:5565 do_read_fault mm/memory.c:6000 [inline] do_fault+0xb3f/0x1830 mm/memory.c:6134 do_pte_missing mm/memory.c:4700 [inline] handle_pte_fault mm/memory.c:6558 [inline] __handle_mm_fault+0x150b/0x2f60 mm/memory.c:6707 handle_mm_fault+0x363/0xa20 mm/memory.c:6876 faultin_page mm/gup.c:1126 [inline] __get_user_pages+0x8ae/0x2c30 mm/gup.c:1428 __get_user_pages_locked mm/gup.c:1692 [inline] get_dump_page+0x27e/0x3d0 mm/gup.c:2192 dump_user_range+0x18d/0xad0 fs/coredump.c:1361 elf_core_dump+0x2d68/0x3d20 fs/binfmt_elf.c:2106 coredump_write fs/coredump.c:1047 [inline] do_coredump fs/coredump.c:1126 [inline] vfs_coredump+0x281a/0x54a0 fs/coredump.c:1195 get_signal+0x1f2a/0x21e0 kernel/signal.c:3036 arch_do_signal_or_restart+0x91/0x7e0 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:66 [inline] exit_to_user_mode_loop kernel/entry/common.c:101 [inline] __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline] irqentry_exit_to_user_mode_prepare include/linux/irq-entry-common.h:244 [inline] irqentry_exit_to_user_mode include/linux/irq-entry-common.h:315 [inline] irqentry_exit+0x402/0xa10 kernel/entry/common.c:165 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:595 RIP: 0033:0x7f437439e161 RSP: 002b:fffffffffffffe70 EFLAGS: 00010217 RAX: 0000000000000000 RBX: 00007f4374626090 RCX: 00007f437439e159 RDX: 0000000000000000 RSI: fffffffffffffe70 RDI: 0000000000008000 RBP: 00007f437443506b R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 00007f4374626128 R14: 00007f4374626090 R15: 00007fffa5564d48 rcu: rcu_preempt kthread starved for 10578 jiffies! g27177 f0x0 RCU_GP_WAIT_FQS(5) ->state=R ->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:28984 pid:17 tgid:17 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5526 [inline] __schedule+0x1259/0x6920 kernel/sched/core.c:7277 __schedule_loop kernel/sched/core.c:7354 [inline] schedule+0xdd/0x2c0 kernel/sched/core.c:7369 schedule_timeout+0x127/0x280 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x1a9/0x8f0 kernel/rcu/tree.c:2122 rcu_gp_kthread+0x17a/0x220 kernel/rcu/tree.c:2330 kthread+0x373/0x450 kernel/kthread.c:436 ret_from_fork+0x730/0xd60 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: 0 Comm: swapper/1 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/05/2026 RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:64 Code: a8 94 02 e9 43 50 03 00 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 e3 c7 1a 00 fb f4 cc cc cc cc 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90 RSP: 0018:ffffc900001a7e00 EFLAGS: 00000246 RAX: 0000000000a9dbc9 RBX: ffff88801f6ccb00 RCX: ffffffff8bd0f185 RDX: 0000000000000001 RSI: ffffffff8e38baa7 RDI: ffffffff8c622e80 RBP: ffffed1003ed9960 R08: 0000000000000001 R09: ffffed10170a67bd R10: ffff8880b8533deb R11: 0000000000000001 R12: 0000000000000000 R13: 0000000000000000 R14: 1ffff92000034fc4 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff888123c59000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f4374387780 CR3: 000000007b37d000 CR4: 00000000003526f0 Call Trace: arch_safe_halt arch/x86/include/asm/paravirt.h:62 [inline] default_idle+0x9/0x10 arch/x86/kernel/process.c:768 default_idle_call+0x6c/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:199 [inline] do_idle+0x3ae/0x5b0 kernel/sched/idle.c:355 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:454 start_secondary+0x21d/0x2d0 arch/x86/kernel/smpboot.c:312 common_startup_64+0x13e/0x158