rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (0 ticks this GP) idle=d174/1/0x4000000000000000 softirq=38089/38090 fqs=39 rcu: (detected by 0, t=10502 jiffies, g=43477, q=663 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 8928 Comm: sed Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] RIP: 0010:_raw_spin_lock_irqsave+0xa3/0xf0 kernel/locking/spinlock.c:162 Code: 02 00 00 74 05 e8 bd dc 1a f7 bf 01 00 00 00 e8 c3 54 ea f6 48 8d 7b 18 31 f6 31 d2 31 c9 41 b8 01 00 00 00 45 31 c9 ff 75 08 78 e0 f5 f6 48 83 c4 08 48 89 df e8 1c 30 f7 f6 48 c7 04 24 0e RSP: 0018:ffffc900001f0bf8 EFLAGS: 00000046 RAX: 0000000000010002 RBX: ffffffff970dff78 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff970dff90 RBP: ffffc900001f0c98 R08: 0000000000000001 R09: 0000000000000000 R10: dffffc0000000000 R11: fffffbfff1c94426 R12: dffffc0000000000 R13: dffffc0000000000 R14: 0000000000000802 R15: 1ffff9200003e180 FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 00000000530b3000 CR4: 00000000003506e0 Call Trace: debug_object_activate+0x6c/0x4b0 lib/debugobjects.c:709 debug_hrtimer_activate kernel/time/hrtimer.c:450 [inline] debug_activate kernel/time/hrtimer.c:505 [inline] enqueue_hrtimer+0x30/0x370 kernel/time/hrtimer.c:1108 __run_hrtimer kernel/time/hrtimer.c:1767 [inline] __hrtimer_run_queues+0x637/0xc40 kernel/time/hrtimer.c:1814 hrtimer_interrupt+0x3c9/0x9c0 kernel/time/hrtimer.c:1876 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+0x9f/0xc0 arch/x86/kernel/apic/apic.c:1088 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687 RIP: 0010:preempt_count arch/x86/include/asm/preempt.h:27 [inline] RIP: 0010:check_kcov_mode kernel/kcov.c:182 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x10/0x60 kernel/kcov.c:216 Code: 89 fb e8 13 00 00 00 48 8b 3d 9c 92 c4 0c 48 89 de 5b e9 43 9d 56 00 cc cc cc f3 0f 1e fa 48 8b 04 24 65 48 8b 0d f0 24 7e 7e <65> 8b 15 f1 24 7e 7e 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 RSP: 0018:ffffc90004b9f758 EFLAGS: 00000246 RAX: ffffffff8a551fe1 RBX: 0000000000000002 RCX: ffff8880220fbc00 RDX: 0000000000000000 RSI: 0000000000000002 RDI: 0000000000000002 RBP: ffffc90004b9f930 R08: ffff8880220fbc00 R09: 0000000000000003 R10: 0000000000000003 R11: 0000000000000000 R12: 0000000000000002 R13: ffff8880776ecc18 R14: 0000000000000002 R15: dffffc0000000000 mas_validate_limits lib/maple_tree.c:7139 [inline] mt_validate+0x12e1/0x4530 lib/maple_tree.c:7231 validate_mm+0xb1/0x420 mm/mmap.c:288 mmap_region+0xeaa/0x2020 mm/mmap.c:2947 do_mmap+0x92f/0x10a0 mm/mmap.c:1385 vm_mmap_pgoff+0x1c0/0x400 mm/util.c:556 ksys_mmap_pgoff+0x520/0x700 mm/mmap.c:1431 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: 0033:0x7f56cbbfe242 Code: 08 00 04 00 00 eb e2 90 41 f7 c1 ff 0f 00 00 75 27 55 89 cd 53 48 89 fb 48 85 ff 74 33 41 89 ea 48 89 df b8 09 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 5e 5b 5d c3 0f 1f 00 c7 05 46 40 01 00 16 00 RSP: 002b:00007fffa5383638 EFLAGS: 00000206 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 00007f56cb924000 RCX: 00007f56cbbfe242 RDX: 0000000000000001 RSI: 0000000000001000 RDI: 00007f56cb924000 RBP: 0000000000000812 R08: 0000000000000003 R09: 0000000000004000 R10: 0000000000000812 R11: 0000000000000206 R12: 00007fffa53836c0 R13: 00007f56cbbdb050 R14: 00007fffa5383a70 R15: 00000ffff4a706ca rcu: rcu_preempt kthread starved for 10423 jiffies! g43477 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:26456 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:2168 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: CPU: 0 PID: 8914 Comm: syz.0.510 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:csd_lock_wait kernel/smp.c:311 [inline] RIP: 0010:smp_call_function_many_cond+0xddf/0x1130 kernel/smp.c:855 Code: 45 8b 2c 24 44 89 ee 83 e6 01 31 ff e8 6a d7 0a 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 a5 d3 0a 00 eb 38 f3 90 <42> 0f b6 04 2b 84 c0 75 11 41 f7 04 24 01 00 00 00 74 1e e8 89 d3 RSP: 0018:ffffc900049bf900 EFLAGS: 00000293 RAX: ffffffff817abd37 RBX: 1ffff110171e826d RCX: ffff888024213c00 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc900049bfa80 R08: ffffffff90d94507 R09: 1ffffffff21b28a0 R10: dffffc0000000000 R11: fffffbfff21b28a1 R12: ffff8880b8f41368 R13: dffffc0000000000 R14: ffff8880b8e3d148 R15: 0000000000000001 FS: 0000555592a8f500(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 0000000065426000 CR4: 00000000003506f0 Call Trace: on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1022 on_each_cpu include/linux/smp.h:71 [inline] text_poke_sync arch/x86/kernel/alternative.c:2222 [inline] text_poke_bp_batch+0x318/0x930 arch/x86/kernel/alternative.c:2432 text_poke_flush arch/x86/kernel/alternative.c:2623 [inline] text_poke_finish+0x30/0x50 arch/x86/kernel/alternative.c:2630 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146 static_key_disable_cpuslocked+0xc5/0x1a0 kernel/jump_label.c:237 static_key_disable+0x1a/0x20 kernel/jump_label.c:245 tracepoint_remove_func kernel/tracepoint.c:417 [inline] tracepoint_probe_unregister+0x6ad/0x930 kernel/tracepoint.c:551 bpf_raw_tp_link_release+0x63/0x90 kernel/bpf/syscall.c:3375 bpf_link_free+0x131/0x310 kernel/bpf/syscall.c:2918 bpf_link_put_direct kernel/bpf/syscall.c:2958 [inline] bpf_link_release+0x6e/0x80 kernel/bpf/syscall.c:2965 __fput+0x234/0x970 fs/file_table.c:384 task_work_run+0x1ce/0x250 kernel/task_work.c:239 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop+0xe6/0x110 kernel/entry/common.c:177 exit_to_user_mode_prepare+0xf6/0x180 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline] syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302 do_syscall_64+0x61/0xb0 arch/x86/entry/common.c:87 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f524e58f749 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:00007ffdbf37e148 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 000000000005cee1 RCX: 00007f524e58f749 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007f524e7e7da0 R08: 0000000000000001 R09: 0000001dbf37e43f R10: 0000001b2c520000 R11: 0000000000000246 R12: 00007f524e7e5fac R13: 00007f524e7e5fa0 R14: ffffffffffffffff R15: 00007ffdbf37e260