rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: (detected by 0, t=10502 jiffies, g=9581, q=796 ncpus=2) rcu: All QSes seen, last rcu_preempt kthread activity 10500 (4294956041-4294945541), jiffies_till_next_fqs=1, root ->qsmask 0x0 rcu: rcu_preempt kthread starved for 10501 jiffies! g9581 f0x2 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:27848 pid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5381 [inline] __schedule+0x15ae/0x4660 kernel/sched/core.c:6700 schedule+0xbd/0x170 kernel/sched/core.c:6774 schedule_timeout+0x188/0x2d0 kernel/time/timer.c:2168 rcu_gp_fqs_loop+0x30d/0x1590 kernel/rcu/tree.c:1667 rcu_gp_kthread+0x9d/0x3b0 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: 5879 Comm: syz.1.17 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 RIP: 0010:lock_release+0xc/0x8c0 kernel/locking/lockdep.c:5762 Code: 4c 89 f7 e8 26 d4 76 00 e9 50 fa ff ff 41 be 2f 00 00 00 e9 66 fa ff ff 66 0f 1f 44 00 00 f3 0f 1e fa 55 48 89 e5 41 57 41 56 <41> 55 41 54 53 48 83 e4 e0 48 81 ec e0 00 00 00 49 89 f4 48 89 7c RSP: 0018:ffffc900001efea0 EFLAGS: 00000087 RAX: 0000000000000003 RBX: 0000000000000001 RCX: ffff888022c6bc00 RDX: 0000000000010100 RSI: ffffffff81ae0b99 RDI: ffffffff8d131da0 RBP: ffffc900001efeb0 R08: ffffffff8e8ae5ef R09: 1ffffffff1d15cbd R10: dffffc0000000000 R11: fffffbfff1d15cbe R12: ffffc900001eff00 R13: ffffc900001f00c0 R14: dffffc0000000000 R15: 1ffff9200003dfdc FS: 00007fb5a699b6c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2d512ff8 CR3: 000000002db1a000 CR4: 00000000003506e0 Call Trace: rcu_lock_release include/linux/rcupdate.h:344 [inline] rcu_read_unlock include/linux/rcupdate.h:819 [inline] __perf_event_output kernel/events/core.c:7978 [inline] perf_event_output_forward+0x330/0x3e0 kernel/events/core.c:7987 __perf_event_overflow+0x461/0x660 kernel/events/core.c:9712 perf_event_overflow kernel/events/core.c:9733 [inline] perf_swevent_hrtimer+0x437/0x610 kernel/events/core.c:11222 __run_hrtimer kernel/time/hrtimer.c:1754 [inline] __hrtimer_run_queues+0x4e8/0xc10 kernel/time/hrtimer.c:1818 hrtimer_interrupt+0x39d/0x980 kernel/time/hrtimer.c:1880 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1077 [inline] __sysvec_apic_timer_interrupt+0xfb/0x3b0 arch/x86/kernel/apic/apic.c:1094 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline] sysvec_apic_timer_interrupt+0x51/0xc0 arch/x86/kernel/apic/apic.c:1088 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687 RIP: 0010:perf_trace_lock_acquire+0xf3/0x400 include/trace/events/lock.h:24 Code: 03 48 85 c0 48 c7 c7 e0 b6 ca 8a 48 0f 45 f8 e8 43 ef 0c 09 48 89 44 24 08 49 8d 5c 24 68 48 89 d8 48 c1 e8 03 42 80 3c 38 00 <74> 08 48 89 df e8 13 2b 78 00 4c 8b 2b e8 7b be 1c 09 89 c3 83 f8 RSP: 0018:ffffc900001f0600 EFLAGS: 00000246 RAX: 1ffffffff19ffa15 RBX: ffffffff8cffd0a8 RCX: 000000008acbdd05 RDX: 0000000000000000 RSI: ffffffff8d131da0 RDI: ffffffff8acbdd80 RBP: ffffc900001f0700 R08: 0000000000000002 R09: 0000000000000000 R10: dffffc0000000000 R11: fffffbfff1d15cbe R12: ffffffff8cffd040 R13: ffffffff8d131da0 R14: 1ffff9200003e0c8 R15: dffffc0000000000 trace_lock_acquire include/trace/events/lock.h:24 [inline] lock_acquire+0x3ef/0x420 kernel/locking/lockdep.c:5725 rcu_lock_acquire include/linux/rcupdate.h:334 [inline] rcu_read_lock include/linux/rcupdate.h:786 [inline] ip_local_deliver_finish+0x1df/0x510 net/ipv4/ip_input.c:232 NF_HOOK+0x32d/0x3b0 include/linux/netfilter.h:304 NF_HOOK+0x32d/0x3b0 include/linux/netfilter.h:304 __netif_receive_skb_one_core net/core/dev.c:5646 [inline] __netif_receive_skb+0xcc/0x290 net/core/dev.c:5760 process_backlog+0x380/0x710 net/core/dev.c:6088 __napi_poll+0xbb/0x460 net/core/dev.c:6650 napi_poll net/core/dev.c:6717 [inline] net_rx_action+0x65f/0xcc0 net/core/dev.c:6853 handle_softirqs+0x27d/0x820 kernel/softirq.c:578 __do_softirq kernel/softirq.c:612 [inline] invoke_softirq kernel/softirq.c:452 [inline] __irq_exit_rcu+0xd3/0x190 kernel/softirq.c:661 irq_exit_rcu+0x9/0x20 kernel/softirq.c:673 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline] sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1088 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687 RIP: 0010:lock_release+0x594/0x8c0 kernel/locking/lockdep.c:5778 Code: 00 00 00 f7 84 24 80 00 00 00 00 02 00 00 43 c6 44 2f 04 f8 75 70 f7 44 24 50 00 02 00 00 74 01 fb 48 c7 44 24 60 0e 36 e0 45 <4b> c7 04 2f 00 00 00 00 43 c7 44 2f 08 00 00 00 00 65 48 8b 04 25 RSP: 0018:ffffc90004ee6aa0 EFLAGS: 00000206 RAX: 0000000000000001 RBX: ffffffffffffffff RCX: cbc9d5a9a29f9c00 RDX: 0000000000000000 RSI: ffffffff8acadce0 RDI: ffffffff8b1c7be0 RBP: ffffc90004ee6bb0 R08: ffffffff8e8ae5ef R09: 1ffffffff1d15cbd R10: dffffc0000000000 R11: fffffbfff1d15cbe R12: ffff888022c6c6e0 R13: dffffc0000000000 R14: ffff888022c6c6d0 R15: 1ffff920009dcd60 rcu_lock_release include/linux/rcupdate.h:344 [inline] rcu_read_unlock include/linux/rcupdate.h:819 [inline] trace_call_bpf+0x5dd/0x6c0 kernel/trace/bpf_trace.c:145 perf_trace_run_bpf_submit+0x7a/0x1c0 kernel/events/core.c:10287 perf_trace_lock_acquire+0x342/0x400 include/trace/events/lock.h:24 trace_lock_acquire include/trace/events/lock.h:24 [inline] lock_acquire+0x3ef/0x420 kernel/locking/lockdep.c:5725 rcu_lock_acquire include/linux/rcupdate.h:334 [inline] rcu_read_lock include/linux/rcupdate.h:786 [inline] is_bpf_text_address+0x47/0x2a0 kernel/bpf/core.c:741 kernel_text_address+0xa0/0xd0 kernel/extable.c:125 __kernel_text_address+0xd/0x30 kernel/extable.c:79 unwind_get_return_address+0x5d/0xc0 arch/x86/kernel/unwind_orc.c:369 arch_stack_walk+0x11d/0x190 arch/x86/kernel/stacktrace.c:26 stack_trace_save+0xaa/0x100 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4e/0x70 mm/kasan/common.c:53 kasan_save_free_info+0x28/0x40 mm/kasan/generic.c:522 ____kasan_slab_free+0x126/0x1f0 mm/kasan/common.c:237 kasan_slab_free include/linux/kasan.h:164 [inline] slab_free_hook mm/slub.c:1811 [inline] slab_free_freelist_hook+0x130/0x1a0 mm/slub.c:1837 slab_free mm/slub.c:3830 [inline] __kmem_cache_free+0xba/0x1f0 mm/slub.c:3843 free_states kernel/bpf/verifier.c:19713 [inline] do_check_common+0xe45/0x1410 kernel/bpf/verifier.c:19797 do_check_main kernel/bpf/verifier.c:19848 [inline] bpf_check+0x65d1/0xec30 kernel/bpf/verifier.c:20516 bpf_prog_load+0x10fa/0x1610 kernel/bpf/syscall.c:2753 __sys_bpf+0x5ba/0x890 kernel/bpf/syscall.c:5477 __do_sys_bpf kernel/bpf/syscall.c:5581 [inline] __se_sys_bpf kernel/bpf/syscall.c:5579 [inline] __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5579 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fb5a5b9de59 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fb5a699b028 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 00007fb5a5e25fa0 RCX: 00007fb5a5b9de59 RDX: 0000000000000048 RSI: 00002000000054c0 RDI: 0000000000000005 RBP: 00007fb5a5c33e6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fb5a5e26038 R14: 00007fb5a5e25fa0 R15: 00007ffc057eb158