rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5832/1:b..l rcu: (detected by 1, t=10504 jiffies, g=22685, q=393 ncpus=2) task:syz-executor state:R running task stack:21960 pid:5832 tgid:5832 ppid:5825 task_flags:0x400140 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5392 [inline] __schedule+0x16f5/0x4d00 kernel/sched/core.c:6781 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7104 irqentry_exit+0x6f/0x90 kernel/entry/common.c:307 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:deref_stack_reg+0x1a7/0x230 arch/x86/kernel/unwind_orc.c:406 Code: 46 49 8d 40 08 48 39 d8 0f 97 c1 4c 39 f0 0f 96 c0 20 c8 3c 01 75 30 4c 89 c7 49 89 f7 e8 11 08 00 00 49 89 c6 48 8b 5c 24 18 <48> 89 d8 48 c1 e8 03 42 80 3c 38 00 74 08 48 89 df e8 73 69 b0 00 RSP: 0018:ffffc90003bff380 EFLAGS: 00000202 RAX: ffffc90003bffec0 RBX: ffffc90003bff4e8 RCX: 0000000000000001 RDX: ffffc90003bff4e8 RSI: dffffc0000000000 RDI: ffffc90003bffdf0 RBP: 1ffff9200077fe95 R08: ffffc90003bffdf0 R09: ffffc90003bff4f8 R10: dffffc0000000000 R11: fffff5200077fea1 R12: 1ffff9200077fe96 R13: 1ffff9200077fe97 R14: ffffc90003bffec0 R15: dffffc0000000000 unwind_next_frame+0x17c4/0x2390 arch/x86/kernel/unwind_orc.c:-1 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:68 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:576 poison_slab_object mm/kasan/common.c:247 [inline] __kasan_slab_free+0x62/0x70 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2380 [inline] slab_free mm/slub.c:4642 [inline] kmem_cache_free+0x18f/0x400 mm/slub.c:4744 f2fs_destroy_node_manager+0x322/0xcc0 fs/f2fs/node.c:3369 f2fs_put_super+0xb15/0x1170 fs/f2fs/super.c:1694 generic_shutdown_super+0x135/0x2c0 fs/super.c:643 kill_block_super+0x44/0x90 fs/super.c:1760 kill_f2fs_super+0x390/0x6c0 fs/f2fs/super.c:5032 deactivate_locked_super+0xbc/0x130 fs/super.c:474 cleanup_mnt+0x425/0x4c0 fs/namespace.c:1432 task_work_run+0x1d4/0x260 kernel/task_work.c:227 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop+0xec/0x110 kernel/entry/common.c:114 exit_to_user_mode_prepare include/linux/entry-common.h:330 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:414 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:449 [inline] do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fd53318fc97 RSP: 002b:00007ffdb3fa01a8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 00007fd53321089d RCX: 00007fd53318fc97 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffdb3fa0260 RBP: 00007ffdb3fa0260 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffdb3fa12f0 R13: 00007fd53321089d R14: 000000000003134d R15: 00007ffdb3fa1330 rcu: rcu_preempt kthread starved for 10502 jiffies! g22685 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:27128 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5392 [inline] __schedule+0x16f5/0x4d00 kernel/sched/core.c:6781 __schedule_loop kernel/sched/core.c:6859 [inline] schedule+0x165/0x360 kernel/sched/core.c:6874 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2054 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2256 kthread+0x711/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 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: 5834 Comm: syz-executor Not tainted 6.15.0-syzkaller-03589-gfeacb1774bd5 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:native_pause arch/x86/include/asm/vdso/processor.h:13 [inline] RIP: 0010:cpu_relax arch/x86/include/asm/vdso/processor.h:18 [inline] RIP: 0010:csd_lock_wait kernel/smp.c:340 [inline] RIP: 0010:smp_call_function_many_cond+0xe67/0x11c0 kernel/smp.c:885 Code: 00 00 00 45 8b 2f 44 89 ee 83 e6 01 31 ff e8 10 74 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 bb 6f 0b 00 eb 37 90 43 0f b6 04 2c 84 c0 75 10 41 f7 07 01 00 00 00 74 1e e8 a0 RSP: 0018:ffffc900042df5a0 EFLAGS: 00000293 RAX: ffffffff81b48780 RBX: ffff8880b873b180 RCX: ffff88802f79bc00 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc900042df700 R08: ffffffff8f9fe8b7 R09: 1ffffffff1f3fd16 R10: dffffc0000000000 R11: fffffbfff1f3fd17 R12: 1ffff110170c8331 R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8880b8641988 FS: 0000555580d97500(0000) GS:ffff888125d8c000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c3afc96 CR3: 0000000030e27000 CR4: 0000000000350ef0 Call Trace: on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1052 __flush_tlb_multi arch/x86/include/asm/paravirt.h:91 [inline] flush_tlb_multi arch/x86/mm/tlb.c:1361 [inline] flush_tlb_mm_range+0x6b1/0x12c0 arch/x86/mm/tlb.c:1451 dup_mmap kernel/fork.c:766 [inline] dup_mm kernel/fork.c:1737 [inline] copy_mm+0x18e2/0x2160 kernel/fork.c:1789 copy_process+0x1706/0x3c00 kernel/fork.c:2429 kernel_clone+0x21e/0x870 kernel/fork.c:2859 __do_sys_clone kernel/fork.c:3002 [inline] __se_sys_clone kernel/fork.c:2986 [inline] __x64_sys_clone+0x18b/0x1e0 kernel/fork.c:2986 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7ff6259851d3 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:00007ffd096c36b8 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007ff6259851d3 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000001 R10: 0000555580d977d0 R11: 0000000000000246 R12: 0000000000000000 R13: 00000000000927c0 R14: 000000000003137f R15: 00007ffd096c3850