rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (1 GPs behind) idle=63c4/1/0x4000000000000000 softirq=120827/120839 fqs=0 rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P16193/1:b..l P19344/3:b..l rcu: (detected by 1, t=10502 jiffies, g=106049, q=231 ncpus=2) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 19341 Comm: syz.1.2977 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:get_current arch/x86/include/asm/current.h:25 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x8/0x70 kernel/kcov.c:216 Code: 8b 3d 54 2b fb 0b 48 89 de 5b e9 23 84 5b 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 8b 04 24 <65> 48 8b 0c 25 08 90 a1 92 65 8b 15 58 d5 e0 10 81 e2 00 01 ff 00 RSP: 0018:ffffc90000007d38 EFLAGS: 00000086 RAX: ffffffff81ae2c77 RBX: ffff8880b86283c8 RCX: ffff88802792bc80 RDX: 0000000000010000 RSI: 1ffff110170c5072 RDI: ffff888028090300 RBP: ffffc90000007e90 R08: ffff888028090317 R09: 0000000000000000 R10: ffff888028090308 R11: ffffed1005012063 R12: ffff888033c1b300 R13: dffffc0000000000 R14: ffff8880b86283d8 R15: ffff8880b8628380 FS: 000055555eb10500(0000) GS:ffff888125c07000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b31720ff8 CR3: 00000000784dc000 CR4: 00000000003526f0 Call Trace: __hrtimer_run_queues+0x6d7/0xc30 kernel/time/hrtimer.c:1821 hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1903 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1045 [inline] __sysvec_apic_timer_interrupt+0x102/0x3e0 arch/x86/kernel/apic/apic.c:1062 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1056 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:__sanitizer_cov_trace_pc+0x5d/0x70 kernel/kcov.c:235 Code: 20 16 00 00 83 fa 02 75 21 48 8b 91 28 16 00 00 48 8b 32 48 8d 7e 01 8b 89 24 16 00 00 48 39 cf 73 08 48 89 3a 48 89 44 f2 08 3e b5 9f 09 cc 66 66 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 RSP: 0018:ffffc9000505f930 EFLAGS: 00000293 RAX: ffffffff81b52d0c RBX: 0000000000000001 RCX: ffff88802792bc80 RDX: 0000000000000000 RSI: ffffffff8be08c40 RDI: ffffffff8be08c00 RBP: 0000000000000001 R08: ffffffff8fa25d77 R09: 1ffffffff1f44bae R10: dffffc0000000000 R11: fffffbfff1f44baf R12: ffff8880b863bdc0 R13: dffffc0000000000 R14: 0000000000000000 R15: 0000000000000000 trace_ipi_send_cpu+0x7c/0x1e0 include/trace/events/ipi.h:10 send_call_function_single_ipi kernel/smp.c:118 [inline] smp_call_function_many_cond+0xa84/0x1260 kernel/smp.c:857 on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1043 on_each_cpu include/linux/smp.h:71 [inline] smp_text_poke_sync_each_cpu arch/x86/kernel/alternative.c:2711 [inline] smp_text_poke_batch_finish+0xe98/0x1130 arch/x86/kernel/alternative.c:3004 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146 static_key_disable_cpuslocked+0xc5/0x1a0 kernel/jump_label.c:240 static_key_disable+0x1a/0x20 kernel/jump_label.c:248 tracepoint_remove_func kernel/tracepoint.c:370 [inline] tracepoint_probe_unregister+0x80e/0x9c0 kernel/tracepoint.c:504 bpf_raw_tp_link_release+0x43/0x70 kernel/bpf/syscall.c:3767 bpf_link_free+0xed/0x330 kernel/bpf/syscall.c:3278 bpf_link_put_direct kernel/bpf/syscall.c:3321 [inline] bpf_link_release+0x6b/0x80 kernel/bpf/syscall.c:3328 __fput+0x44c/0xa70 fs/file_table.c:468 task_work_run+0x1d4/0x260 kernel/task_work.c:233 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] __exit_to_user_mode_loop kernel/entry/common.c:44 [inline] exit_to_user_mode_loop+0xef/0x4e0 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+0x2c1/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f5d62b8f749 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:00007ffd01395eb8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 000000000011fe57 RCX: 00007f5d62b8f749 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007f5d62de7da0 R08: 0000000000000001 R09: 00000009013961af R10: 0000001b30720000 R11: 0000000000000246 R12: 00007f5d62de5fac R13: 00007f5d62de5fa0 R14: ffffffffffffffff R15: 00007ffd01395fd0 task:syz-executor state:R running task stack:28504 pid:19344 tgid:19344 ppid:8257 task_flags:0x400040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5282 [inline] __schedule+0x14ed/0x5040 kernel/sched/core.c:6894 preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:7078 preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12 __raw_spin_unlock include/linux/spinlock_api_smp.h:169 [inline] _raw_spin_unlock+0x3f/0x50 kernel/locking/spinlock.c:186 spin_unlock include/linux/spinlock.h:392 [inline] filemap_map_pages+0x192d/0x1fd0 mm/filemap.c:3931 do_fault_around mm/memory.c:5695 [inline] do_read_fault mm/memory.c:5728 [inline] do_fault mm/memory.c:5871 [inline] do_pte_missing+0x20b0/0x3330 mm/memory.c:4416 handle_pte_fault mm/memory.c:6255 [inline] __handle_mm_fault mm/memory.c:6393 [inline] handle_mm_fault+0x1b26/0x32b0 mm/memory.c:6562 do_user_addr_fault+0xa7c/0x1380 arch/x86/mm/fault.c:1336 handle_page_fault arch/x86/mm/fault.c:1476 [inline] exc_page_fault+0x71/0xd0 arch/x86/mm/fault.c:1532 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618 RIP: 0033:0x7f649d3572c0 RSP: 002b:00007ffe1bdf8b28 EFLAGS: 00010212 RAX: 00000000000003c0 RBX: 0000000000000016 RCX: 0000000000000000 RDX: 0000000000000016 RSI: 00007f649d4157ac RDI: 00007ffe1bdf93c0 RBP: 0000000000000016 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f649d4157c2 R13: 0000000000000016 R14: 00007ffe1bdf90d0 R15: 00007ffe1bdf90d0 task:syz-executor state:R running task stack:20744 pid:16193 tgid:16193 ppid:16182 task_flags:0x400140 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5282 [inline] __schedule+0x14ed/0x5040 kernel/sched/core.c:6894 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7221 irqentry_exit+0x5e3/0x670 kernel/entry/common.c:216 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:rcu_is_watching+0x0/0xb0 kernel/rcu/tree.c:748 Code: c7 c7 a0 39 14 8e e8 bf bd 21 03 eb cc 66 66 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 41 57 41 56 53 65 ff 05 a0 cc fa 10 e8 db e8 b6 09 89 RSP: 0018:ffffc9000215f250 EFLAGS: 00000202 RAX: 0000000000000001 RBX: ffffffff81000130 RCX: ffff88802f951e40 RDX: 00000000ae70feff RSI: ffffffff8db845c0 RDI: ffffffff8be08c60 RBP: dffffc0000000000 R08: ffffffff8173fd75 R09: ffffffff8e13efa0 R10: ffffc9000215f378 R11: ffffffff81acb2b0 R12: 1ffff9200042be65 R13: ffffc9000215f360 R14: ffffc9000215f328 R15: ffffffff8173fd75 rcu_read_lock include/linux/rcupdate.h:851 [inline] class_rcu_constructor include/linux/rcupdate.h:1193 [inline] unwind_next_frame+0xd4/0x23d0 arch/x86/kernel/unwind_orc.c:495 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 save_stack+0xf5/0x1f0 mm/page_owner.c:165 __reset_page_owner+0x71/0x1f0 mm/page_owner.c:320 reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1436 [inline] free_unref_folios+0xcc0/0x13e0 mm/page_alloc.c:3033 folios_put_refs+0x584/0x670 mm/swap.c:1002 folio_batch_release include/linux/pagevec.h:101 [inline] shmem_undo_range+0x49e/0x1490 mm/shmem.c:1137 shmem_truncate_range mm/shmem.c:1249 [inline] shmem_evict_inode+0x26e/0xa70 mm/shmem.c:1379 evict+0x5f4/0xae0 fs/inode.c:837 do_unlinkat+0x41d/0x5d0 fs/namei.c:5516 __do_sys_unlink fs/namei.c:5547 [inline] __se_sys_unlink fs/namei.c:5545 [inline] __x64_sys_unlink+0x47/0x50 fs/namei.c:5545 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fc8c438ecf7 RSP: 002b:00007fffe4671d38 EFLAGS: 00000206 ORIG_RAX: 0000000000000057 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fc8c438ecf7 RDX: 00007fffe4671d60 RSI: 00007fffe4671df0 RDI: 00007fffe4671df0 RBP: 00007fffe4671df0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000100 R11: 0000000000000206 R12: 00007fffe4672e80 R13: 00007fc8c4413d7d R14: 000000000011f315 R15: 00007fffe4672ec0 rcu: rcu_preempt kthread starved for 10502 jiffies! g106049 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->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:27512 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5282 [inline] __schedule+0x14ed/0x5040 kernel/sched/core.c:6894 __schedule_loop kernel/sched/core.c:6976 [inline] schedule+0x165/0x360 kernel/sched/core.c:6991 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x301/0x11b0 kernel/rcu/tree.c:2095 rcu_gp_kthread+0x9b/0x2d0 kernel/rcu/tree.c:2297 kthread+0x389/0x480 kernel/kthread.c:467 ret_from_fork+0x510/0xa50 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: 1 UID: 0 PID: 18568 Comm: syz-executor 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:csd_lock_wait kernel/smp.c:342 [inline] RIP: 0010:smp_call_function_many_cond+0xcc5/0x1260 kernel/smp.c:877 Code: 45 8b 2c 24 44 89 ee 83 e6 01 31 ff e8 94 a3 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 3f 9f 0b 00 eb 38 f3 90 <42> 0f b6 04 2b 84 c0 75 11 41 f7 04 24 01 00 00 00 74 1e e8 23 9f RSP: 0018:ffffc90002ef7640 EFLAGS: 00000293 RAX: ffffffff81b51b9d RBX: 1ffff110170c85c9 RCX: ffff88801eb21e40 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc90002ef7768 R08: ffffffff8fa25d77 R09: 1ffffffff1f44bae R10: dffffc0000000000 R11: fffffbfff1f44baf R12: ffff8880b8642e48 R13: dffffc0000000000 R14: ffff8880b873bdc0 R15: 0000000000000000 FS: 000055558c102500(0000) GS:ffff888125d07000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b3041fff8 CR3: 000000008fcc8000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 000000000000000e DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1043 __flush_tlb_multi arch/x86/include/asm/paravirt.h:91 [inline] flush_tlb_multi arch/x86/mm/tlb.c:1382 [inline] flush_tlb_mm_range+0x60a/0x1170 arch/x86/mm/tlb.c:1472 dup_mmap+0x15fa/0x1b80 mm/mmap.c:1866 dup_mm kernel/fork.c:1529 [inline] copy_mm+0x13c/0x4b0 kernel/fork.c:1581 copy_process+0x1812/0x3ba0 kernel/fork.c:2218 kernel_clone+0x21e/0x820 kernel/fork.c:2648 __do_sys_clone kernel/fork.c:2789 [inline] __se_sys_clone kernel/fork.c:2773 [inline] __x64_sys_clone+0x18b/0x1e0 kernel/fork.c:2773 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7ff599185e93 Code: 1f 84 00 00 00 00 00 64 48 8b 04 25 10 00 00 00 45 31 c0 31 d2 31 f6 bf 11 00 20 01 4c 8d 90 d0 02 00 00 b8 38 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 35 89 c2 85 c0 75 2c 64 48 8b 04 25 10 00 00 RSP: 002b:00007fff7bea0428 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007ff599185e93 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000001 R10: 000055558c1027d0 R11: 0000000000000246 R12: 0000000000000000 R13: 00000000000927c0 R14: 000000000011fc92 R15: 00007fff7bea05c0