rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (1 GPs behind) idle=f28c/1/0x4000000000000000 softirq=20317/20319 fqs=1 rcu: (detected by 1, t=10505 jiffies, g=17233, q=925 ncpus=2) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 7589 Comm: syz.0.740 Not tainted 6.12.0-rc7-syzkaller-00042-gf1b785f4c787 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/30/2024 RIP: 0010:hlock_id kernel/locking/lockdep.c:430 [inline] RIP: 0010:__lock_acquire+0xaab/0x3ce0 kernel/locking/lockdep.c:5190 Code: 44 24 68 89 7c 24 60 48 b8 00 00 00 00 00 fc ff df 48 8b 54 24 30 48 c1 ea 03 0f b6 04 02 84 c0 74 08 3c 03 0f 8e 58 2c 00 00 <41> 0f b7 45 20 66 25 ff 1f 66 89 44 24 20 41 0f b6 45 22 83 e0 03 RSP: 0018:ffffc90000007af0 EFLAGS: 00000046 RAX: 0000000000000000 RBX: b29849a635ae3d5f RCX: ffffffff816a68f8 RDX: 1ffff1100cdd35ed RSI: 0000000000000008 RDI: 0000000029849a6b RBP: 0000000000000000 R08: 0000000000000000 R09: fffffbfff2dc5d88 R10: ffffffff96e2ec47 R11: 0000000000000000 R12: dffffc0000000000 R13: ffff888066e9af48 R14: 0000000000000002 R15: ffff888066e9a440 FS: 00007efcca3f66c0(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020e8a030 CR3: 0000000030882000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5825 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x3a/0x60 kernel/locking/spinlock.c:162 debug_object_deactivate+0x13c/0x370 lib/debugobjects.c:763 debug_hrtimer_deactivate kernel/time/hrtimer.c:428 [inline] debug_deactivate kernel/time/hrtimer.c:484 [inline] __run_hrtimer kernel/time/hrtimer.c:1659 [inline] __hrtimer_run_queues+0x47c/0xae0 kernel/time/hrtimer.c:1755 hrtimer_interrupt+0x31b/0x800 kernel/time/hrtimer.c:1817 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1038 [inline] __sysvec_apic_timer_interrupt+0x10f/0x400 arch/x86/kernel/apic/apic.c:1055 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline] sysvec_apic_timer_interrupt+0x9f/0xc0 arch/x86/kernel/apic/apic.c:1049 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0x31/0x80 kernel/locking/spinlock.c:194 Code: f5 53 48 8b 74 24 10 48 89 fb 48 83 c7 18 e8 66 a2 44 f6 48 89 df e8 7e 1f 45 f6 f7 c5 00 02 00 00 75 23 9c 58 f6 c4 02 75 37 01 00 00 00 e8 95 28 36 f6 65 8b 05 a6 e1 dd 74 85 c0 74 16 5b RSP: 0018:ffffc90003d6f640 EFLAGS: 00000246 RAX: 0000000000000006 RBX: ffff8880252e9100 RCX: 1ffffffff20be2f1 RDX: 0000000000000000 RSI: ffffffff8b6ccfc0 RDI: ffffffff8bd1b3c0 RBP: 0000000000000246 R08: 0000000000000001 R09: 0000000000000001 R10: ffffffff905f59cf R11: 0000000000000000 R12: ffff8880252e90e8 R13: ffff88806978ec80 R14: 0000000000000246 R15: ffffc90003d6f780 spin_unlock_irqrestore include/linux/spinlock.h:406 [inline] __skb_try_recv_datagram+0x177/0x4f0 net/core/datagram.c:266 __skb_recv_datagram+0x1a0/0x220 net/core/datagram.c:296 skb_recv_datagram+0x89/0xc0 net/core/datagram.c:316 netlink_recvmsg+0x115/0xf30 net/netlink/af_netlink.c:1923 sock_recvmsg_nosec net/socket.c:1051 [inline] ____sys_recvmsg+0x5f8/0x6b0 net/socket.c:2824 ___sys_recvmsg+0x115/0x1a0 net/socket.c:2868 do_recvmmsg+0x2ba/0x750 net/socket.c:2962 __sys_recvmmsg net/socket.c:3041 [inline] __do_sys_recvmmsg net/socket.c:3064 [inline] __se_sys_recvmmsg net/socket.c:3057 [inline] __x64_sys_recvmmsg+0x239/0x290 net/socket.c:3057 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7efccbf7e719 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:00007efcca3f6038 EFLAGS: 00000246 ORIG_RAX: 000000000000012b RAX: ffffffffffffffda RBX: 00007efccc135f80 RCX: 00007efccbf7e719 RDX: 03ffffffffffff81 RSI: 0000000020000780 RDI: 0000000000000003 RBP: 00007efccbff1616 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007efccc135f80 R15: 00007ffdf6d63f48 rcu: rcu_preempt kthread starved for 10500 jiffies! g17233 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:28448 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5328 [inline] __schedule+0xe55/0x5740 kernel/sched/core.c:6693 __schedule_loop kernel/sched/core.c:6770 [inline] schedule+0xe7/0x350 kernel/sched/core.c:6785 schedule_timeout+0x136/0x2a0 kernel/time/timer.c:2615 rcu_gp_fqs_loop+0x1eb/0xb00 kernel/rcu/tree.c:2045 rcu_gp_kthread+0x271/0x380 kernel/rcu/tree.c:2247 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 rcu: Stack dump where RCU GP kthread last ran: CPU: 1 UID: 0 PID: 11 Comm: kworker/u8:0 Not tainted 6.12.0-rc7-syzkaller-00042-gf1b785f4c787 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/30/2024 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:handle_softirqs+0x1da/0x8f0 kernel/softirq.c:540 Code: 89 44 24 18 48 89 6c 24 10 48 c7 c7 a0 70 6b 8b e8 4b 22 d3 09 65 66 c7 05 f9 70 b3 7e 00 00 e8 3c bd 44 00 fb bb ff ff ff ff <49> c7 c6 c0 a0 e0 8d 41 0f bc dc 83 c3 01 0f 85 a4 00 00 00 e9 b1 RSP: 0018:ffffc90000a18f30 EFLAGS: 00000206 RAX: 0000000000a97044 RBX: 00000000ffffffff RCX: 1ffffffff2dc5ec7 RDX: 0000000000000000 RSI: ffffffff8b6ccfc0 RDI: ffffffff8bd1b3c0 RBP: ffff88801d6aa440 R08: 0000000000000001 R09: fffffbfff2dc5d88 R10: ffffffff96e2ec47 R11: 0000000000000000 R12: 0000000000000100 R13: 000000000000000a R14: 0000000000000001 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020db0030 CR3: 000000000df7c000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __do_softirq kernel/softirq.c:588 [inline] invoke_softirq kernel/softirq.c:428 [inline] __irq_exit_rcu kernel/softirq.c:637 [inline] irq_exit_rcu+0xbb/0x120 kernel/softirq.c:649 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline] sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1049 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:csd_lock_wait kernel/smp.c:340 [inline] RIP: 0010:smp_call_function_many_cond+0x458/0x1300 kernel/smp.c:884 Code: 0c 00 85 ed 74 4d 48 b8 00 00 00 00 00 fc ff df 4d 89 f4 4c 89 f5 49 c1 ec 03 83 e5 07 49 01 c4 83 c5 03 e8 8a 1b 0c 00 f3 90 <41> 0f b6 04 24 40 38 c5 7c 08 84 c0 0f 85 a4 0c 00 00 8b 43 08 31 RSP: 0018:ffffc90000107998 EFLAGS: 00000293 RAX: 0000000000000000 RBX: ffff8880b8646b80 RCX: ffffffff81815ffc RDX: ffff88801d6aa440 RSI: ffffffff81815fd6 RDI: 0000000000000005 RBP: 0000000000000003 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: ffffed10170c8d71 R13: 0000000000000001 R14: ffff8880b8646b88 R15: ffff8880b8740100 on_each_cpu_cond_mask+0x40/0x90 kernel/smp.c:1051 on_each_cpu include/linux/smp.h:71 [inline] text_poke_sync arch/x86/kernel/alternative.c:2085 [inline] text_poke_bp_batch+0x22b/0x760 arch/x86/kernel/alternative.c:2295 text_poke_flush arch/x86/kernel/alternative.c:2486 [inline] text_poke_flush arch/x86/kernel/alternative.c:2483 [inline] text_poke_finish+0x30/0x40 arch/x86/kernel/alternative.c:2493 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146 jump_label_update+0x1d7/0x400 kernel/jump_label.c:920 static_key_enable_cpuslocked+0x1b7/0x270 kernel/jump_label.c:210 static_key_enable+0x1a/0x20 kernel/jump_label.c:223 toggle_allocation_gate mm/kfence/core.c:849 [inline] toggle_allocation_gate+0xfc/0x260 mm/kfence/core.c:841 process_one_work+0x9c5/0x1ba0 kernel/workqueue.c:3229 process_scheduled_works kernel/workqueue.c:3310 [inline] worker_thread+0x6c8/0xf00 kernel/workqueue.c:3391 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244