rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	1-...!: (1 GPs behind) idle=6914/1/0x4000000000000000 softirq=61904/61905 fqs=1
rcu: 	(detected by 0, t=10506 jiffies, g=59573, q=596 ncpus=2)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 14002 Comm: syz.1.2212 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
RIP: 0010:memset_orig+0x0/0xb0 arch/x86/lib/memset_64.S:49
Code: 49 89 f9 40 88 f0 48 89 d1 f3 aa 4c 89 c8 c3 cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <49> 89 fa 40 0f b6 ce 48 b8 01 01 01 01 01 01 01 01 48 0f af c1 41
RSP: 0018:ffffc90000a08c80 EFLAGS: 00000002
RAX: 524178e6277eb601 RBX: ffff8880298f9340 RCX: ffffffff84d74478
RDX: 0000000000000010 RSI: 0000000000000000 RDI: ffffc90000a08ca0
RBP: 0000000000000000 R08: ffffc90000a08caf R09: 1ffff92000141195
R10: dffffc0000000000 R11: fffff52000141196 R12: dffffc0000000000
R13: dffffc0000000000 R14: ffffffff8bad0920 R15: ffff8880b8727bc0
FS:  00007f9bf41aa6c0(0000) GS:ffff888125afc000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: fffffffffffffffd CR3: 000000002557c000 CR4: 00000000003526f0
Call Trace:
 <IRQ>
 debug_object_activate+0x38/0x420 lib/debugobjects.c:806
 debug_hrtimer_activate kernel/time/hrtimer.c:438 [inline]
 debug_activate kernel/time/hrtimer.c:477 [inline]
 enqueue_hrtimer+0x30/0x3a0 kernel/time/hrtimer.c:1081
 __run_hrtimer kernel/time/hrtimer.c:1794 [inline]
 __hrtimer_run_queues+0x656/0xc60 kernel/time/hrtimer.c:1841
 hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1903
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1041 [inline]
 __sysvec_apic_timer_interrupt+0x10b/0x410 arch/x86/kernel/apic/apic.c:1058
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1052 [inline]
 sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1052
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
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 2b b2 45 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 <e8> d3 3a 0e f6 65 8b 05 dc e8 3f 07 85 c0 74 40 48 c7 04 24 0e 36
RSP: 0018:ffffc9000258fb60 EFLAGS: 00000206
RAX: 524178e6277eb600 RBX: 0000000000000a06 RCX: 524178e6277eb600
RDX: 0000000000000007 RSI: ffffffff8dba1162 RDI: 0000000000000001
RBP: ffffc9000258fbf0 R08: ffffffff8fc36c77 R09: 1ffffffff1f86d8e
R10: dffffc0000000000 R11: fffffbfff1f86d8f R12: dffffc0000000000
R13: ffff8880b8627ac0 R14: ffff8880b8627ac0 R15: 1ffff920004b1f6c
 clock_was_set+0x63b/0x7c0 kernel/time/hrtimer.c:965
 do_settimeofday64+0x41d/0x630 kernel/time/timekeeping.c:1460
 __do_sys_clock_settime kernel/time/posix-timers.c:1131 [inline]
 __se_sys_clock_settime kernel/time/posix-timers.c:1115 [inline]
 __x64_sys_clock_settime+0x22c/0x280 kernel/time/posix-timers.c:1115
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f9bf338eec9
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:00007f9bf41aa038 EFLAGS: 00000246 ORIG_RAX: 00000000000000e3
RAX: ffffffffffffffda RBX: 00007f9bf35e5fa0 RCX: 00007f9bf338eec9
RDX: 0000000000000000 RSI: 0000200000000100 RDI: 0000000000000000
RBP: 00007f9bf3411f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f9bf35e6038 R14: 00007f9bf35e5fa0 R15: 00007ffe28284308
 </TASK>
rcu: rcu_preempt kthread starved for 10500 jiffies! g59573 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:26464 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5325 [inline]
 __schedule+0x1798/0x4cc0 kernel/sched/core.c:6929
 __schedule_loop kernel/sched/core.c:7011 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:7026
 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99
 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2083
 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2285
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 0 UID: 0 PID: 13987 Comm: syz.6.2206 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
RIP: 0010:check_kcov_mode kernel/kcov.c:185 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x31/0x70 kernel/kcov.c:217
Code: 24 65 48 8b 0c 25 08 40 c2 92 65 8b 15 d8 ed 01 11 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 35 83 b9 7c 16 00 00 00 74 2c <8b> 91 58 16 00 00 83 fa 02 75 21 48 8b 91 60 16 00 00 48 8b 32 48
RSP: 0018:ffffc9000447f338 EFLAGS: 00000246
RAX: ffffffff81b4e31b RBX: 1ffff110170e7ffd RCX: ffff88802c281e40
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc9000447f4c0 R08: ffffffff8fc36c77 R09: 1ffffffff1f86d8e
R10: dffffc0000000000 R11: fffffbfff1f86d8f R12: ffff8880b873ffe8
R13: dffffc0000000000 R14: ffff8880b863b200 R15: 0000000000000001
FS:  0000000000000000(0000) GS:ffff8881259fc000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: fffffffffffffffd CR3: 000000000e138000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 csd_lock_wait kernel/smp.c:342 [inline]
 smp_call_function_many_cond+0xd4b/0x12d0 kernel/smp.c:877
 on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1043
 __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+0x6b1/0x12d0 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
 free_ldt_pgtables+0x17b/0x320 arch/x86/kernel/ldt.c:411
 arch_exit_mmap arch/x86/include/asm/mmu_context.h:234 [inline]
 exit_mmap+0x174/0xb40 mm/mmap.c:1266
 __mmput+0x118/0x430 kernel/fork.c:1133
 exit_mm+0x1da/0x2c0 kernel/exit.c:582
 do_exit+0x648/0x2300 kernel/exit.c:954
 do_group_exit+0x21c/0x2d0 kernel/exit.c:1107
 get_signal+0x1285/0x1340 kernel/signal.c:3034
 arch_do_signal_or_restart+0xa0/0x790 arch/x86/kernel/signal.c:337
 exit_to_user_mode_loop+0x72/0x130 kernel/entry/common.c:40
 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
 syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline]
 do_syscall_64+0x2bd/0xfa0 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ff0a598eec9
Code: Unable to access opcode bytes at 0x7ff0a598ee9f.
RSP: 002b:00007ff0a68180e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007ff0a5be5fa8 RCX: 00007ff0a598eec9
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007ff0a5be5fa8
RBP: 00007ff0a5be5fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ff0a5be6038 R14: 00007ffcb8eec510 R15: 00007ffcb8eec5f8
 </TASK>