rcu: INFO: rcu_preempt detected expedited stalls on CPUs/tasks: { 1-.... } 2687 jiffies s: 66133 root: 0x2/. rcu: blocking rcu_node structures (internal RCU debug): Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 18025 Comm: kworker/u4:16 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 Workqueue: events_unbound nsim_dev_trap_report_work RIP: 0010:__kasan_check_read+0x0/0x10 mm/kasan/shadow.c:31 Code: 41 5c 41 5d 41 5e 41 5f 5d c3 48 c7 c7 ea ce 60 8c eb 0a 48 c7 c7 01 76 45 8c 48 89 de e8 98 5b 4c 08 31 ed eb d7 00 00 cc cc <89> f6 48 8b 0c 24 31 d2 e9 c3 ec ff ff 0f 1f 00 89 f6 48 8b 0c 24 RSP: 0018:ffffc900001e01f8 EFLAGS: 00000046 RAX: 0000000000000000 RBX: 0000000000000005 RCX: ffffffff81640229 RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff90af2240 RBP: ffffc900001e0430 R08: dffffc0000000000 R09: 1ffffffff215e44b R10: dffffc0000000000 R11: fffffbfff215e44c R12: ffff8880252029c8 R13: ffff888025201e02 R14: 000000000000002c R15: ffff8880252029c8 FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fa13d217dac CR3: 000000000c88e000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: instrument_atomic_read include/linux/instrumented.h:72 [inline] _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline] hlock_class kernel/locking/lockdep.c:228 [inline] check_wait_context kernel/locking/lockdep.c:4748 [inline] __lock_acquire+0x929/0x7bd0 kernel/locking/lockdep.c:4999 lock_acquire+0x1bb/0x4a0 kernel/locking/lockdep.c:5662 rcu_lock_acquire include/linux/rcupdate.h:350 [inline] rcu_read_lock include/linux/rcupdate.h:791 [inline] trace_call_bpf+0xe0/0x6b0 kernel/trace/bpf_trace.c:134 perf_trace_run_bpf_submit+0x79/0x1c0 kernel/events/core.c:10027 perf_trace_preemptirq_template+0x268/0x320 include/trace/events/preemptirq.h:14 trace_irq_enable_rcuidle+0xd3/0x140 include/trace/events/preemptirq.h:40 trace_hardirqs_on+0x24/0x40 kernel/trace/trace_preemptirq.c:44 asm_sysvec_irq_work+0x16/0x20 arch/x86/include/asm/idtentry.h:728 RIP: 0010:rcu_read_unlock_special+0x7f/0x510 kernel/rcu/tree_plugin.h:685 Code: eb 03 48 b8 f1 f1 f1 f1 f8 f2 f2 f2 4a 89 04 2b 42 c7 44 2b 08 f8 f3 f3 f3 65 44 8b 35 e2 82 95 7e 41 f7 c6 00 00 f0 00 74 40 <48> c7 44 24 40 0e 36 e0 45 4a c7 04 2b 00 00 00 00 42 c7 44 2b 08 RSP: 0018:ffffc900001e08a0 EFLAGS: 00000206 RAX: ad5d0f6bbe1d9900 RBX: 1ffff9200003c11c RCX: ad5d0f6bbe1d9900 RDX: dffffc0000000000 RSI: ffffffff8a8c17a0 RDI: ffffffff8adee1a0 RBP: ffffc900001e0988 R08: ffffffff90af232f R09: 1ffffffff215e465 R10: dffffc0000000000 R11: fffffbfff215e466 R12: 0000000000000246 R13: dffffc0000000000 R14: ffff8880b8f3bb00 R15: 0000000000000002 __rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:426 rcu_read_unlock include/linux/rcupdate.h:823 [inline] percpu_ref_put_many include/linux/percpu-refcount.h:337 [inline] percpu_ref_put+0xef/0x180 include/linux/percpu-refcount.h:351 obj_cgroup_put include/linux/memcontrol.h:795 [inline] refill_obj_stock+0x402/0x6a0 mm/memcontrol.c:3347 memcg_slab_free_hook+0x123/0x200 mm/slab.h:569 slab_free mm/slub.c:3682 [inline] kmem_cache_free+0xe0/0x2a0 mm/slub.c:3709 rcu_do_batch kernel/rcu/tree.c:2297 [inline] rcu_core+0x9a3/0x1740 kernel/rcu/tree.c:2557 handle_softirqs+0x291/0x910 kernel/softirq.c:596 __do_softirq kernel/softirq.c:630 [inline] invoke_softirq kernel/softirq.c:470 [inline] __irq_exit_rcu+0x13b/0x230 kernel/softirq.c:679 irq_exit_rcu+0x5/0x20 kernel/softirq.c:691 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline] sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1118 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691 RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0xbc/0x120 kernel/locking/spinlock.c:194 Code: c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f7 44 24 20 00 02 00 00 41 c6 04 07 f8 75 4b f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 ef cb 23 f7 65 8b 05 f0 7c cd 75 85 c0 74 3c 48 c7 04 24 0e 36 RSP: 0018:ffffc9000e4978c0 EFLAGS: 00000206 RAX: dffffc0000000004 RBX: 0000000000000a06 RCX: ad5d0f6bbe1d9900 RDX: dffffc0000000000 RSI: ffffffff8a8c17a0 RDI: 0000000000000001 RBP: ffffc9000e497958 R08: ffffffff90af232f R09: 1ffffffff215e465 R10: dffffc0000000000 R11: fffffbfff215e466 R12: dffffc0000000000 R13: ffffea0001548000 R14: ffff8880174409c0 R15: 1ffff92001c92f18 spin_unlock_irqrestore include/linux/spinlock.h:406 [inline] get_partial_node+0x469/0x480 mm/slub.c:2252 get_partial mm/slub.c:2330 [inline] ___slab_alloc+0x96d/0x1240 mm/slub.c:3131 __slab_alloc mm/slub.c:3240 [inline] slab_alloc_node mm/slub.c:3325 [inline] __kmem_cache_alloc_node+0x126/0x270 mm/slub.c:3398 __do_kmalloc_node mm/slab_common.c:935 [inline] __kmalloc_node_track_caller+0xa0/0x240 mm/slab_common.c:956 kmalloc_reserve net/core/skbuff.c:446 [inline] __alloc_skb+0x226/0x7d0 net/core/skbuff.c:515 alloc_skb include/linux/skbuff.h:1303 [inline] nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:748 [inline] nsim_dev_trap_report drivers/net/netdevsim/dev.c:805 [inline] nsim_dev_trap_report_work+0x24f/0xa80 drivers/net/netdevsim/dev.c:851 process_one_work+0x8ab/0x1160 kernel/workqueue.c:2292 worker_thread+0xaf5/0x12a0 kernel/workqueue.c:2439 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295