rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (1 ticks this GP) idle=4db4/1/0x4000000000000000 softirq=20042/20042 fqs=5 rcu: (detected by 1, t=10502 jiffies, g=12365, q=899 ncpus=2) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 6229 Comm: syz-executor.0 Not tainted 6.16.0-syzkaller-g038d61fd6422 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 RIP: 0010:match_held_lock+0x3/0xc0 kernel/locking/lockdep.c:5308 Code: 5f c3 cc cc cc cc cc e8 fb f8 ff ff 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 41 56 53 01 00 00 00 48 39 77 10 74 6a 81 7f 20 00 00 20 00 72 5f 48 8b RSP: 0018:ffffc90000007c00 EFLAGS: 00000006 RAX: 0000000000000003 RBX: 000000000000000a RCX: 825878e9f0296100 RDX: 0000000000000001 RSI: ffffffff99cc9f70 RDI: ffff88805fe54740 RBP: ffff88805fe54740 R08: 0000000000000003 R09: 0000000000000004 R10: dffffc0000000000 R11: fffff52000000f70 R12: 0000000000000002 R13: 0000000000000002 R14: ffffffff99cc9f70 R15: ffff88805fe53c00 FS: 00007fe3d88386c0(0000) GS:ffff888125c57000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fe3d8838d58 CR3: 0000000076850000 CR4: 00000000003526f0 Call Trace: find_held_lock kernel/locking/lockdep.c:5353 [inline] __lock_release kernel/locking/lockdep.c:5538 [inline] lock_release+0x127/0x3e0 kernel/locking/lockdep.c:5892 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:149 [inline] _raw_spin_unlock_irqrestore+0x70/0x110 kernel/locking/spinlock.c:194 debug_hrtimer_deactivate kernel/time/hrtimer.c:450 [inline] debug_deactivate+0x1d/0x200 kernel/time/hrtimer.c:490 __run_hrtimer kernel/time/hrtimer.c:1729 [inline] __hrtimer_run_queues+0x2b0/0xc60 kernel/time/hrtimer.c:1825 hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1887 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1039 [inline] __sysvec_apic_timer_interrupt+0x108/0x410 arch/x86/kernel/apic/apic.c:1056 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1050 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+0xa8/0x110 kernel/locking/spinlock.c:194 Code: 74 05 e8 fb 9b 5e f6 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f6 44 24 21 02 75 4f f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 63 cc 27 f6 65 8b 05 1c 7a 33 07 85 c0 74 40 48 c7 04 24 0e 36 RSP: 0018:ffffc90004a8f8e0 EFLAGS: 00000206 RAX: 825878e9f0296100 RBX: 0000000000000a02 RCX: 825878e9f0296100 RDX: 0000000000000007 RSI: ffffffff8d982fca RDI: 0000000000000001 RBP: ffffc90004a8f970 R08: ffffffff8fa0b3f7 R09: 1ffffffff1f4167e R10: dffffc0000000000 R11: fffffbfff1f4167f R12: dffffc0000000000 R13: ffff8880b8627ac0 R14: ffff8880b8627ac0 R15: 1ffff92000951f1c clock_was_set+0x63b/0x7c0 kernel/time/hrtimer.c:972 timekeeping_inject_offset+0x35b/0x4b0 kernel/time/timekeeping.c:1446 do_adjtimex+0x43f/0x9f0 kernel/time/timekeeping.c:2554 do_clock_adjtime kernel/time/posix-timers.c:1162 [inline] __do_sys_clock_adjtime kernel/time/posix-timers.c:1174 [inline] __se_sys_clock_adjtime kernel/time/posix-timers.c:1165 [inline] __x64_sys_clock_adjtime+0x1f4/0x2b0 kernel/time/posix-timers.c:1165 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fe3d7a7dea9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 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 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fe3d88380c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000131 RAX: ffffffffffffffda RBX: 00007fe3d7bac050 RCX: 00007fe3d7a7dea9 RDX: 0000000000000000 RSI: 0000000020000280 RDI: 0000000000000000 RBP: 00007fe3d7aca4a4 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000006e R14: 00007fe3d7bac050 R15: 00007ffcc292e0d8 rcu: rcu_preempt kthread starved for 10492 jiffies! g12365 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:27128 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5397 [inline] __schedule+0x16aa/0x4c90 kernel/sched/core.c:6786 __schedule_loop kernel/sched/core.c:6864 [inline] schedule+0x165/0x360 kernel/sched/core.c:6879 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2054 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2256 kthread+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 rcu: Stack dump where RCU GP kthread last ran: CPU: 1 UID: 0 PID: 5501 Comm: dhcpcd Not tainted 6.16.0-syzkaller-g038d61fd6422 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 RIP: 0010:csd_lock_wait kernel/smp.c:340 [inline] RIP: 0010:smp_call_function_many_cond+0xf69/0x12d0 kernel/smp.c:885 Code: 00 45 8b 2f 44 89 ee 83 e6 01 31 ff e8 80 6e 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 2b 6a 0b 00 eb 37 f3 90 <43> 0f b6 04 2c 84 c0 75 10 41 f7 07 01 00 00 00 74 1e e8 10 6a 0b RSP: 0018:ffffc9000397f580 EFLAGS: 00000293 RAX: ffffffff81b4bbb0 RBX: ffff8880b873b040 RCX: ffff888031b3bc00 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc9000397f6e0 R08: ffffffff8fa0b3f7 R09: 1ffffffff1f4167e R10: dffffc0000000000 R11: fffffbfff1f4167f R12: 1ffff110170c835d R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8880b8641ae8 FS: 00007f746caca740(0000) GS:ffff888125d57000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f746ca08ff8 CR3: 0000000033950000 CR4: 00000000003526f0 Call Trace: on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1052 __flush_tlb_multi arch/x86/include/asm/paravirt.h:91 [inline] flush_tlb_multi arch/x86/mm/tlb.c:1361 [inline] flush_tlb_mm_range+0x6b1/0x12c0 arch/x86/mm/tlb.c:1451 tlb_flush arch/x86/include/asm/tlb.h:23 [inline] tlb_flush_mmu_tlbonly include/asm-generic/tlb.h:490 [inline] tlb_flush_mmu+0x1a7/0x680 mm/mmu_gather.c:403 tlb_finish_mmu+0xc3/0x1d0 mm/mmu_gather.c:497 vms_clear_ptes+0x42c/0x540 mm/vma.c:1230 vms_complete_munmap_vmas+0x206/0x8a0 mm/vma.c:1272 do_vmi_align_munmap+0x358/0x420 mm/vma.c:1531 do_vmi_munmap+0x253/0x2e0 mm/vma.c:1579 __vm_munmap+0x23b/0x3d0 mm/vma.c:3108 __do_sys_munmap mm/mmap.c:1084 [inline] __se_sys_munmap mm/mmap.c:1081 [inline] __x64_sys_munmap+0x60/0x70 mm/mmap.c:1081 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f746cbcb097 Code: 73 01 c3 48 8b 0d 61 2d 0d 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 0b 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 31 2d 0d 00 f7 d8 64 89 01 48 RSP: 002b:00007ffca6382ac8 EFLAGS: 00000202 ORIG_RAX: 000000000000000b RAX: ffffffffffffffda RBX: 0000000000009000 RCX: 00007f746cbcb097 RDX: 00007f746cbb8dd0 RSI: 0000000000009000 RDI: 00007f746ca00000 RBP: 00007f746ca00000 R08: 0000000000001857 R09: 0000000000000000 R10: 0000000000000008 R11: 0000000000000202 R12: 0000000000000000 R13: 00007ffca6382b00 R14: 0000000000000001 R15: 00007f746cbb8dd0