rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (1 GPs behind) idle=2e8c/1/0x4000000000000000 softirq=104642/104644 fqs=0 rcu: (detected by 0, t=10505 jiffies, g=128869, q=559 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 25 Comm: kworker/1:0 Not tainted 6.12.0-rc3-syzkaller-00007-g6485cf5ea253 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Workqueue: events nsim_dev_trap_report_work RIP: 0010:instrument_atomic_read include/linux/instrumented.h:68 [inline] RIP: 0010:_test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline] RIP: 0010:hlock_class+0x35/0x130 kernel/locking/lockdep.c:228 Code: 48 89 fb 48 83 c7 20 48 89 fa 48 c1 ea 03 0f b6 04 02 84 c0 74 08 3c 03 0f 8e da 00 00 00 0f b7 5b 20 66 81 e3 ff 1f 0f b7 db 08 00 00 00 48 89 d8 48 c1 e8 06 48 8d 3c c5 40 6c e2 96 e8 12 RSP: 0018:ffffc90000a18ae0 EFLAGS: 00000002 RAX: 0000000000000000 RBX: 000000000000006e RCX: ffffffff816a7178 RDX: 1ffff11003bdd534 RSI: 0000000000000008 RDI: ffff88801deea9a0 RBP: 0000000000000000 R08: 0000000000000000 R09: fffffbfff2dc4d88 R10: 0000000000000005 R11: 0000000000000000 R12: dffffc0000000000 R13: ffff88801deea9a8 R14: 0000000000000002 R15: ffff88801dee9e00 FS: 0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2e31eff8 CR3: 000000002bfd8000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __lock_acquire+0x1443/0x3ce0 kernel/locking/lockdep.c:5198 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:1026 [inline] __sysvec_apic_timer_interrupt+0x10f/0x450 arch/x86/kernel/apic/apic.c:1043 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1037 [inline] sysvec_apic_timer_interrupt+0x9f/0xc0 arch/x86/kernel/apic/apic.c:1037 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 b6 3e 46 f6 48 89 df e8 ce bb 46 f6 f7 c5 00 02 00 00 75 23 9c 58 f6 c4 02 75 37 01 00 00 00 e8 85 be 37 f6 65 8b 05 76 75 df 74 85 c0 74 16 5b RSP: 0018:ffffc900001f7988 EFLAGS: 00000246 RAX: 0000000000000002 RBX: ffffffff9a9abcd0 RCX: 1ffffffff2dd1ca3 RDX: 0000000000000000 RSI: ffffffff8b6cd040 RDI: ffffffff8bd1a1c0 RBP: 0000000000000286 R08: 0000000000000001 R09: fffffbfff2dc4da9 R10: ffffffff96e26d4f R11: 0000000000000000 R12: ffff88807ab46000 R13: 000000000000001c R14: 000000000000001c R15: ffff88807ab46000 __debug_check_no_obj_freed lib/debugobjects.c:998 [inline] debug_check_no_obj_freed+0x328/0x600 lib/debugobjects.c:1019 slab_free_hook mm/slub.c:2273 [inline] slab_free mm/slub.c:4579 [inline] kfree+0x2b3/0x4b0 mm/slub.c:4727 skb_kfree_head net/core/skbuff.c:1086 [inline] skb_free_head+0x108/0x1d0 net/core/skbuff.c:1098 skb_release_data+0x560/0x730 net/core/skbuff.c:1125 skb_release_all net/core/skbuff.c:1190 [inline] __kfree_skb net/core/skbuff.c:1204 [inline] consume_skb net/core/skbuff.c:1436 [inline] consume_skb+0xbf/0x100 net/core/skbuff.c:1430 nsim_dev_trap_report drivers/net/netdevsim/dev.c:821 [inline] nsim_dev_trap_report_work+0x878/0xc80 drivers/net/netdevsim/dev.c:850 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 rcu: rcu_preempt kthread starved for 10505 jiffies! g128869 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0 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:27504 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5322 [inline] __schedule+0xef5/0x5750 kernel/sched/core.c:6682 __schedule_loop kernel/sched/core.c:6759 [inline] schedule+0xe7/0x350 kernel/sched/core.c:6774 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: 0 UID: 0 PID: 35 Comm: kworker/u8:2 Not tainted 6.12.0-rc3-syzkaller-00007-g6485cf5ea253 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:write_comp_data+0x8b/0x90 kernel/kcov.c:272 Code: 00 00 4a 8d 34 dd 28 00 00 00 48 39 f2 72 1b 48 83 c7 01 48 89 38 4c 89 44 30 e0 4c 89 4c 30 e8 4c 89 54 30 f0 4a 89 4c d8 20 cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 RSP: 0018:ffffc90000ab7990 EFLAGS: 00000293 RAX: 0000000000000000 RBX: ffff8880b8744cc0 RCX: ffffffff8181675c RDX: ffff88801e2a3c00 RSI: 0000000000000000 RDI: 0000000000000005 RBP: 0000000000000003 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: ffffed10170e8999 R13: 0000000000000001 R14: ffff8880b8744cc8 R15: ffff8880b8640100 FS: 0000000000000000(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055558754b808 CR3: 000000000df7c000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: csd_lock_wait kernel/smp.c:340 [inline] smp_call_function_many_cond+0x47c/0x1300 kernel/smp.c:884 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