rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5155/1:b..l rcu: (detected by 0, t=10502 jiffies, g=10445, q=543 ncpus=2) task:udevd state:R running task stack:25160 pid:5155 ppid:1 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:3329 __netlink_sendskb net/netlink/af_netlink.c:1276 [inline] netlink_sendskb+0x9b/0x130 net/netlink/af_netlink.c:1282 netlink_sendmsg+0x8c1/0xbe0 net/netlink/af_netlink.c:1904 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg net/socket.c:745 [inline] ____sys_sendmsg+0x5bf/0x950 net/socket.c:2595 ___sys_sendmsg+0x220/0x290 net/socket.c:2649 __sys_sendmsg net/socket.c:2678 [inline] __do_sys_sendmsg net/socket.c:2687 [inline] __se_sys_sendmsg+0x1a5/0x270 net/socket.c:2685 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: 0033:0x7f47e00a7407 RSP: 002b:00007fff2a64f610 EFLAGS: 00000202 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f47e075c880 RCX: 00007f47e00a7407 RDX: 0000000000000000 RSI: 00007fff2a64f670 RDI: 0000000000000004 RBP: 0000563ee6e641c0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 00000000000000b2 R13: 0000563ee6e519e0 R14: 0000000000000000 R15: 0000000000000000 rcu: rcu_preempt kthread starved for 10528 jiffies! g10445 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:26440 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: Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 6017 Comm: syz.2.19 Not tainted 6.6.102-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 RIP: 0010:__lock_acquire+0xdb2/0x7c80 kernel/locking/lockdep.c:5107 Code: 89 d8 48 c1 e8 06 48 8d 3c c5 00 35 da 90 be 08 00 00 00 e8 90 c2 75 00 49 b8 00 00 00 00 00 fc ff df 48 0f a3 1d 6e 23 73 0f <0f> 83 16 50 00 00 49 8d 9d d0 0a 00 00 48 89 d8 48 c1 e8 03 48 89 RSP: 0018:ffffc900001f09e0 EFLAGS: 00000057 RAX: 0000000000000001 RBX: 00000000000000ad RCX: ffffffff81671180 RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff90da3510 RBP: ffffc900001f0c28 R08: dffffc0000000000 R09: 1ffffffff21b46a2 R10: dffffc0000000000 R11: fffffbfff21b46a3 R12: 0000000000000002 R13: ffff888027deda00 R14: ffff888027dee530 R15: ffff888027dee550 FS: 00007fee0f91a6c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 000000002dbea000 CR4: 00000000003506e0 Call Trace: lock_acquire+0x197/0x410 kernel/locking/lockdep.c:5754 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xa8/0xf0 kernel/locking/spinlock.c:162 __lock_task_sighand+0x14a/0x2d0 kernel/signal.c:1424 lock_task_sighand include/linux/sched/signal.h:742 [inline] do_send_sig_info kernel/signal.c:1311 [inline] group_send_sig_info+0x1de/0x260 kernel/signal.c:1462 do_bpf_send_signal+0x7f/0x190 kernel/trace/bpf_trace.c:836 irq_work_single+0xd5/0x230 kernel/irq_work.c:221 irq_work_run_list kernel/irq_work.c:252 [inline] irq_work_run+0x156/0x2e0 kernel/irq_work.c:261 __sysvec_irq_work+0x98/0x380 arch/x86/kernel/irq_work.c:22 instr_sysvec_irq_work arch/x86/kernel/irq_work.c:17 [inline] sysvec_irq_work+0x9c/0xc0 arch/x86/kernel/irq_work.c:17 asm_sysvec_irq_work+0x1a/0x20 arch/x86/include/asm/idtentry.h:723 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 61 18 03 0f 1f 80 00 00 00 RSP: 0018:ffffc9000373fcb8 EFLAGS: 00000246 RAX: 00000000000000f6 RBX: 0000000000000200 RCX: 000000000000083f RDX: 0000000000000000 RSI: 00000000000000f6 RDI: 000000000000083f RBP: 0000000000000000 R08: ffffc9000373fc27 R09: 1ffff920006e7f84 R10: dffffc0000000000 R11: fffff520006e7f85 R12: ffff8880b8f35201 R13: dffffc0000000000 R14: ffff8880b8f35290 R15: 0000000000000020 __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:1213 [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: 0033:0x7fee0eb2add9 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:00007fee0f919b40 EFLAGS: 00000246 ORIG_RAX: 000000000000000f RAX: ffffffffffffffda RBX: 00007fee0edb5fa8 RCX: 00007fee0eb2add9 RDX: 00007fee0f919b40 RSI: 00007fee0f919c70 RDI: 0000000000000011 RBP: 00007fee0edb5fa0 R08: 0000000000745a3f R09: 0000000000000000 R10: 0000000000000005 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fee0edb6038 R14: 00007ffc83c2e530 R15: 00007ffc83c2e618