rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P12722/1:b..l P13262/1:b..l P9931/1:b..l P13288/1:b..l rcu: (detected by 1, t=10502 jiffies, g=55469, q=515 ncpus=2) task:syz.6.1556 state:R running task stack:27720 pid:13288 tgid:13288 ppid:10362 task_flags:0x40044c flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5397 [inline] __schedule+0x116a/0x5dd0 kernel/sched/core.c:6786 preempt_schedule_common+0x44/0xc0 kernel/sched/core.c:6966 preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12 __raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline] _raw_spin_unlock+0x3e/0x50 kernel/locking/spinlock.c:186 spin_unlock include/linux/spinlock.h:391 [inline] zap_pte_range mm/memory.c:1765 [inline] zap_pmd_range mm/memory.c:1827 [inline] zap_pud_range mm/memory.c:1856 [inline] zap_p4d_range mm/memory.c:1877 [inline] unmap_page_range+0x106b/0x4350 mm/memory.c:1898 unmap_single_vma.constprop.0+0x153/0x240 mm/memory.c:1941 unmap_vmas+0x218/0x470 mm/memory.c:1985 exit_mmap+0x1b9/0xb90 mm/mmap.c:1284 __mmput+0x12a/0x410 kernel/fork.c:1121 mmput+0x62/0x70 kernel/fork.c:1144 exit_mm kernel/exit.c:581 [inline] do_exit+0x7c4/0x2bd0 kernel/exit.c:952 do_group_exit+0xd3/0x2a0 kernel/exit.c:1105 get_signal+0x2673/0x26d0 kernel/signal.c:3034 arch_do_signal_or_restart+0x8f/0x7d0 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:330 [inline] irqentry_exit_to_user_mode+0x12a/0x270 kernel/entry/common.c:184 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 RIP: 0033:0x7f334366ecfd RSP: 002b:00007ffe515f0f70 EFLAGS: 00010202 RAX: 000000110c24c000 RBX: 00007f33444e5720 RCX: 0000000000000004 RDX: 0000000000001fe0 RSI: 0000000000003aff RDI: 0000000000000010 RBP: ffffffff81febfe0 R08: 00007f33439b6038 R09: 00007f33439a2000 R10: 00007f3342dff008 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: ffffffff81febe32 R15: 00000000000002d6 task:udevd state:R running task stack:25896 pid:9931 tgid:9931 ppid:5201 task_flags:0x400140 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5397 [inline] __schedule+0x116a/0x5dd0 kernel/sched/core.c:6786 preempt_schedule_common+0x44/0xc0 kernel/sched/core.c:6966 preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] _raw_spin_unlock_irqrestore+0x61/0x80 kernel/locking/spinlock.c:194 sock_def_readable+0x15b/0x600 net/core/sock.c:3583 unix_dgram_sendmsg+0xc97/0x17a0 net/unix/af_unix.c:2236 sock_sendmsg_nosec net/socket.c:712 [inline] __sock_sendmsg net/socket.c:727 [inline] sock_write_iter+0x4ff/0x5b0 net/socket.c:1131 new_sync_write fs/read_write.c:593 [inline] vfs_write+0x6c4/0x1150 fs/read_write.c:686 ksys_write+0x1f8/0x250 fs/read_write.c:738 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f3cc5aa7407 RSP: 002b:00007fffd701a6f0 EFLAGS: 00000202 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f3cc6147880 RCX: 00007f3cc5aa7407 RDX: 0000000000000000 RSI: 00007fffd701a797 RDI: 000000000000000a RBP: 000000000000000a R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 00007f3cc61476e8 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 task:syz.9.1551 state:R running task stack:25352 pid:13262 tgid:13262 ppid:9631 task_flags:0x40044c flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5397 [inline] __schedule+0x116a/0x5dd0 kernel/sched/core.c:6786 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7109 irqentry_exit+0x36/0x90 kernel/entry/common.c:307 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:__rcu_read_lock+0xa7/0xf0 kernel/rcu/tree_plugin.h:416 Code: 48 b8 00 00 00 00 00 fc ff df 89 9d 44 04 00 00 65 48 8b 1d d3 ab 2e 12 48 8d bb 44 04 00 00 48 89 fa 48 c1 ea 03 0f b6 14 02 <48> 89 f8 83 e0 07 83 c0 03 38 d0 7c 04 84 d2 75 1f 8b 83 44 04 00 RSP: 0018:ffffc900137e72e8 EFLAGS: 00000a03 RAX: dffffc0000000000 RBX: ffff888030f04880 RCX: ffffc900137e72c4 RDX: 0000000000000000 RSI: ffffffff823b8d61 RDI: ffff888030f04cc4 RBP: ffff888030f04880 R08: ffffffff917574d0 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000038c9c R12: ffffffff81a78cf0 R13: ffffc900137e7370 R14: 0000000000000000 R15: ffff888030f04880 rcu_read_lock include/linux/rcupdate.h:839 [inline] class_rcu_constructor include/linux/rcupdate.h:1155 [inline] unwind_next_frame+0xae/0x20a0 arch/x86/kernel/unwind_orc.c:479 arch_stack_walk+0x94/0x100 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_record_aux_stack+0xa7/0xc0 mm/kasan/generic.c:548 __call_rcu_common.constprop.0+0xa5/0xa10 kernel/rcu/tree.c:3094 security_inode_free+0xa4/0x170 security/security.c:1735 __destroy_inode+0x201/0x730 fs/inode.c:371 destroy_inode+0x91/0x1b0 fs/inode.c:394 evict+0x5b4/0x920 fs/inode.c:834 iput_final fs/inode.c:1898 [inline] iput fs/inode.c:1924 [inline] iput+0x521/0x880 fs/inode.c:1910 dentry_unlink_inode+0x29c/0x480 fs/dcache.c:466 __dentry_kill+0x1d0/0x600 fs/dcache.c:669 dput.part.0+0x4b1/0x9b0 fs/dcache.c:911 dput+0x1f/0x30 fs/dcache.c:901 find_next_child+0x18f/0x280 fs/libfs.c:603 simple_recursive_removal+0x253/0x690 fs/libfs.c:619 debugfs_remove+0x5d/0x80 fs/debugfs/inode.c:805 kvm_destroy_vm_debugfs+0xc6/0x250 virt/kvm/kvm_main.c:1007 kvm_destroy_vm virt/kvm/kvm_main.c:1271 [inline] kvm_put_kvm+0xff/0xb40 virt/kvm/kvm_main.c:1344 kvm_vm_release+0x3c/0x50 virt/kvm/kvm_main.c:1367 __fput+0x3ff/0xb70 fs/file_table.c:465 task_work_run+0x14d/0x240 kernel/task_work.c:227 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x86c/0x2bd0 kernel/exit.c:964 do_group_exit+0xd3/0x2a0 kernel/exit.c:1105 get_signal+0x2673/0x26d0 kernel/signal.c:3034 arch_do_signal_or_restart+0x8f/0x7d0 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:330 [inline] irqentry_exit_to_user_mode+0x12a/0x270 kernel/entry/common.c:184 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0033:0x7f51f7467de4 RSP: 002b:00007ffd27e72650 EFLAGS: 00000283 RAX: 00007f51f6d4d118 RBX: 00007f51f6d4bcc8 RCX: ffffffff81a867d8 RDX: ffffffff81a867d8 RSI: ffffffff81a86b47 RDI: 00007f51f6d4f8c8 RBP: 00007f51f6d4abd8 R08: 00007f51f6d4d248 R09: 00007f51f77a2000 R10: 00007f51f6bff008 R11: 000000000000000a R12: 00007f51f6d4abd0 R13: 0000000000000018 R14: 00007ffd27e72808 R15: 00007f51f6bff008 task:kworker/1:13 state:R running task stack:27384 pid:12722 tgid:12722 ppid:2 task_flags:0x4208060 flags:0x00004000 Workqueue: events_power_efficient gc_worker Call Trace: context_switch kernel/sched/core.c:5397 [inline] __schedule+0x116a/0x5dd0 kernel/sched/core.c:6786 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7109 irqentry_exit+0x36/0x90 kernel/entry/common.c:307 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 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 5d 4e 5a 00 be 03 00 00 00 5b e9 92 07 1f 03 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 17 14 12 65 8b 05 a9 17 14 12 a9 00 01 ff 00 74 1d RSP: 0018:ffffc9000ba7fb50 EFLAGS: 00000202 RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffffffff89ab7223 RDX: ffff88806d144880 RSI: ffffffff89ab663f RDI: 0000000000000001 RBP: ffffffff9b26fa8c R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000001 R12: ffff888031e00000 R13: 0000000000040000 R14: dffffc0000000000 R15: 0000000000001629 native_save_fl arch/x86/include/asm/irqflags.h:26 [inline] arch_local_save_flags arch/x86/include/asm/irqflags.h:109 [inline] arch_local_irq_save arch/x86/include/asm/irqflags.h:127 [inline] seqcount_lockdep_reader_access include/linux/seqlock.h:71 [inline] nf_conntrack_get_ht include/net/netfilter/nf_conntrack.h:344 [inline] gc_worker+0x25f/0x16e0 net/netfilter/nf_conntrack_core.c:1551 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3238 process_scheduled_works kernel/workqueue.c:3321 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3402 kthread+0x3c5/0x780 kernel/kthread.c:464 ret_from_fork+0x5d4/0x6f0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 rcu: rcu_preempt kthread starved for 10165 jiffies! g55469 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:27272 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5397 [inline] __schedule+0x116a/0x5dd0 kernel/sched/core.c:6786 __schedule_loop kernel/sched/core.c:6864 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6879 schedule_timeout+0x123/0x290 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x1ea/0xb00 kernel/rcu/tree.c:2054 rcu_gp_kthread+0x270/0x380 kernel/rcu/tree.c:2256 kthread+0x3c5/0x780 kernel/kthread.c:464 ret_from_fork+0x5d4/0x6f0 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: 0 Comm: swapper/1 Not tainted 6.16.0-rc7-syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:82 Code: 6b 6d 02 e9 83 fb 02 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 43 89 23 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:ffffc90000197df8 EFLAGS: 000002c6 RAX: 0000000002818e93 RBX: 0000000000000001 RCX: ffffffff8b868c99 RDX: 0000000000000000 RSI: ffffffff8de2ff26 RDI: ffffffff8c1573e0 RBP: ffffed1003c56488 R08: 0000000000000001 R09: ffffed10170a6645 R10: ffff8880b853322b R11: 0000000000000001 R12: 0000000000000001 R13: ffff88801e2b2440 R14: ffffffff90a94050 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888124820000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055858b936a90 CR3: 000000003461b000 CR4: 00000000003526f0 Call Trace: arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:749 default_idle_call+0x6d/0xb0 kernel/sched/idle.c:117 cpuidle_idle_call kernel/sched/idle.c:185 [inline] do_idle+0x391/0x510 kernel/sched/idle.c:325 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:423 start_secondary+0x21d/0x2b0 arch/x86/kernel/smpboot.c:315 common_startup_64+0x13e/0x148