rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P6119/3:b..l P6095/1:b..l P5874/1:b..l rcu: (detected by 1, t=10502 jiffies, g=12837, q=790 ncpus=2) task:udevd state:R running task stack:26056 pid:5874 ppid:5158 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5380 [inline] __schedule+0x14d2/0x44d0 kernel/sched/core.c:6699 preempt_schedule_common+0x82/0xc0 kernel/sched/core.c:6866 preempt_schedule+0xab/0xc0 kernel/sched/core.c:6890 preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk_64.S:45 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] _raw_spin_unlock_irqrestore+0xfa/0x110 kernel/locking/spinlock.c:194 spin_unlock_irqrestore include/linux/spinlock.h:406 [inline] __wake_up_common_lock kernel/sched/wait.c:140 [inline] __wake_up_sync_key+0x11f/0x190 kernel/sched/wait.c:213 sock_def_readable+0x1e1/0x430 net/core/sock.c:3351 unix_dgram_sendmsg+0x10cc/0x1720 net/unix/af_unix.c:2141 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg net/socket.c:745 [inline] sock_write_iter+0x2bb/0x3f0 net/socket.c:1160 call_write_iter include/linux/fs.h:2018 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x43b/0x940 fs/read_write.c:584 ksys_write+0x147/0x250 fs/read_write.c:637 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f8b4eaa7407 RSP: 002b:00007ffc4b9b7b80 EFLAGS: 00000202 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f8b4f14d880 RCX: 00007f8b4eaa7407 RDX: 0000000000000000 RSI: 00007ffc4b9b7c27 RDI: 000000000000000a RBP: 000000000000000a R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 00007f8b4f14d6e8 R13: 0000000000000000 R14: 0000000000000000 R15: 00005573c76b8830 task:kworker/1:6 state:R running task stack:25704 pid:6095 ppid:2 flags:0x00004000 Workqueue: events_power_efficient gc_worker Call Trace: context_switch kernel/sched/core.c:5380 [inline] __schedule+0x14d2/0x44d0 kernel/sched/core.c:6699 preempt_schedule_irq+0xb5/0x140 kernel/sched/core.c:7009 irqentry_exit+0x67/0x70 kernel/entry/common.c:438 asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:692 RIP: 0010:seqcount_lockdep_reader_access+0x17f/0x1c0 include/linux/seqlock.h:105 Code: f8 4d 85 e4 75 16 e8 40 a3 d9 f8 eb 15 e8 39 a3 d9 f8 e8 e4 81 c2 01 4d 85 e4 74 ea e8 2a a3 d9 f8 fb 48 c7 04 24 0e 36 e0 45 <4b> c7 04 3e 00 00 00 00 66 43 c7 44 3e 09 00 00 43 c6 44 3e 0b 00 RSP: 0018:ffffc900048af9a0 EFLAGS: 00000293 RAX: ffffffff88abe7c6 RBX: 0000000000000000 RCX: ffff88802a52bc00 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc900048afa50 R08: ffffffff90da7597 R09: 1ffffffff21b4eb2 R10: dffffc0000000000 R11: fffffbfff21b4eb3 R12: 0000000000000200 R13: dffffc0000000000 R14: 1ffff92000915f34 R15: dffffc0000000000 nf_conntrack_get_ht include/net/netfilter/nf_conntrack.h:350 [inline] gc_worker+0x317/0x14b0 net/netfilter/nf_conntrack_core.c:1504 process_one_work kernel/workqueue.c:2634 [inline] process_scheduled_works+0xa45/0x15b0 kernel/workqueue.c:2711 worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 task:modprobe state:R running task stack:24232 pid:6119 ppid:1065 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5380 [inline] __schedule+0x14d2/0x44d0 kernel/sched/core.c:6699 preempt_schedule_common+0x82/0xc0 kernel/sched/core.c:6866 preempt_schedule+0xab/0xc0 kernel/sched/core.c:6890 preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk_64.S:45 __raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline] _raw_spin_unlock+0x3a/0x40 kernel/locking/spinlock.c:186 spin_unlock include/linux/spinlock.h:391 [inline] filemap_map_pages+0x1069/0x1630 mm/filemap.c:3655 do_fault_around mm/memory.c:4573 [inline] do_read_fault mm/memory.c:4606 [inline] do_fault mm/memory.c:4753 [inline] do_pte_missing mm/memory.c:3688 [inline] handle_pte_fault mm/memory.c:5025 [inline] __handle_mm_fault mm/memory.c:5166 [inline] handle_mm_fault+0x379b/0x4920 mm/memory.c:5331 do_user_addr_fault+0xad0/0x12e0 arch/x86/mm/fault.c:1324 handle_page_fault arch/x86/mm/fault.c:1465 [inline] exc_page_fault+0x67/0x110 arch/x86/mm/fault.c:1521 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:608 RIP: 0033:0x7f86d315ed90 RSP: 002b:00007ffc15128d98 EFLAGS: 00010202 RAX: 00007f86d31dbe38 RBX: 00007ffc15128e38 RCX: 00007f86d31d3960 RDX: 00007ffc15128e60 RSI: 000000000000002f RDI: 00007ffc15129f98 RBP: 00007ffc15129f98 R08: 00007f86d32daaf8 R09: 0000000000000000 R10: 00007ffc15128a60 R11: 0000000000000246 R12: 00007ffc15128e38 R13: 00007ffc15128e60 R14: 00007f86d31d0c40 R15: 0000000000000000 rcu: rcu_preempt kthread starved for 10577 jiffies! g12837 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:27752 pid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5380 [inline] __schedule+0x14d2/0x44d0 kernel/sched/core.c:6699 schedule+0xbd/0x170 kernel/sched/core.c:6773 schedule_timeout+0x160/0x280 kernel/time/timer.c:2167 rcu_gp_fqs_loop+0x302/0x1560 kernel/rcu/tree.c:1667 rcu_gp_kthread+0x99/0x380 kernel/rcu/tree.c:1866 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 rcu: Stack dump where RCU GP kthread last ran: CPU: 1 PID: 6116 Comm: syz.0.78 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 RIP: 0010:arch_static_branch arch/x86/include/asm/jump_label.h:27 [inline] RIP: 0010:static_key_false include/linux/jump_label.h:207 [inline] RIP: 0010:native_write_msr arch/x86/include/asm/msr.h:147 [inline] RIP: 0010:wrmsr arch/x86/include/asm/msr.h:254 [inline] RIP: 0010:native_apic_msr_write+0x39/0x50 arch/x86/include/asm/apic.h:196 Code: 74 2a 83 ff 30 74 25 eb 10 81 ff d0 00 00 00 74 1b 81 ff e0 00 00 00 74 13 c1 ef 04 81 c7 00 08 00 00 89 f9 89 f0 31 d2 0f 30 <66> 90 c3 f3 0f 1e fa 89 f6 31 d2 e9 47 e9 18 03 0f 1f 80 00 00 00 RSP: 0018:ffffc9000461fcb8 EFLAGS: 00000246 RAX: 00000000000000f6 RBX: 0000000000000200 RCX: 000000000000083f RDX: 0000000000000000 RSI: 00000000000000f6 RDI: 000000000000083f RBP: 0000000000000000 R08: ffffc9000461fc27 R09: 1ffff920008c3f84 R10: dffffc0000000000 R11: fffff520008c3f85 R12: ffff8880b8f35001 R13: dffffc0000000000 R14: ffff8880b8f35050 R15: 0000000000000020 FS: 00007faca39a26c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 000000007c95b000 CR4: 00000000003506e0 Call Trace: __apic_send_IPI_self arch/x86/include/asm/apic.h:454 [inline] arch_irq_work_raise+0x68/0x70 arch/x86/kernel/irq_work.c:31 irq_work_queue+0x99/0x140 kernel/irq_work.c:124 bpf_send_signal_common+0x2b6/0x420 kernel/trace/bpf_trace.c:875 ____bpf_send_signal kernel/trace/bpf_trace.c:884 [inline] bpf_send_signal+0x19/0x20 kernel/trace/bpf_trace.c:882 bpf_prog_7ba5217f62dcd359+0x40/0x44 bpf_dispatcher_nop_func include/linux/bpf.h:1223 [inline] __bpf_prog_run include/linux/filter.h:612 [inline] bpf_prog_run include/linux/filter.h:619 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2322 [inline] bpf_trace_run2+0x1d1/0x3c0 kernel/trace/bpf_trace.c:2361 __traceiter_sys_enter+0x2a/0x40 include/trace/events/syscalls.h:18 trace_sys_enter+0x69/0x80 include/trace/events/syscalls.h:18 syscall_trace_enter+0xf0/0x150 kernel/entry/common.c:81 do_syscall_64+0x28/0xb0 arch/x86/entry/common.c:77 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7faca2b2af79 Code: 64 c7 00 16 00 00 00 b8 ff ff ff ff c3 0f 1f 40 00 90 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 c7 c0 0f 00 00 00 0f 05 <0f> 1f 80 00 00 00 00 48 81 ec 48 01 00 00 49 89 d0 64 48 8b 04 25 RSP: 002b:00007faca39a1b40 EFLAGS: 00000246 ORIG_RAX: 000000000000000f RAX: ffffffffffffffda RBX: 00007faca2de5fa8 RCX: 00007faca2b2af79 RDX: 00007faca39a1b40 RSI: 00007faca39a1c70 RDI: 0000000000000011 RBP: 00007faca2de5fa0 R08: 0000000000745d1e R09: 0000000000000000 R10: 0000000000000005 R11: 0000000000000246 R12: 0000000000000000 R13: 00007faca2de6038 R14: 00007ffef216e590 R15: 00007ffef216e678 sched: RT throttling activated