rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	1-...!: (1 GPs behind) idle=4fec/0/0x1 softirq=20649/20650 fqs=1
rcu: 	(detected by 0, t=10502 jiffies, g=15865, q=166 ncpus=2)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:preempt_count arch/x86/include/asm/preempt.h:27 [inline]
RIP: 0010:check_kcov_mode kernel/kcov.c:183 [inline]
RIP: 0010:write_comp_data kernel/kcov.c:246 [inline]
RIP: 0010:__sanitizer_cov_trace_cmp8+0xd/0x90 kernel/kcov.c:294
Code: cc cc 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 48 8b 04 24 65 48 8b 0c 25 08 e0 4a 92 <65> 8b 15 cc 75 8b 10 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75
RSP: 0018:ffffc90000a08d00 EFLAGS: 00000046
RAX: ffffffff8b2116a4 RBX: ffff8880b8928490 RCX: ffff88801ca8dac0
RDX: 0000000000010000 RSI: ffff8880793c3300 RDI: 0000000000000001
RBP: 1ffff1100f278660 R08: ffffffff8f5adcb7 R09: 1ffffffff1eb5b96
R10: dffffc0000000000 R11: fffffbfff1eb5b97 R12: ffff8880793c3300
R13: dffffc0000000000 R14: ffff8880793c3300 R15: 0000000000000001
FS:  0000000000000000(0000) GS:ffff888126472000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f4d07f72a60 CR3: 000000000db38000 CR4: 00000000003526f0
Call Trace:
 <IRQ>
 timerqueue_del+0x44/0x100 lib/timerqueue.c:55
 __remove_hrtimer kernel/time/hrtimer.c:1114 [inline]
 __run_hrtimer kernel/time/hrtimer.c:1757 [inline]
 __hrtimer_run_queues+0x360/0xc10 kernel/time/hrtimer.c:1841
 hrtimer_interrupt+0x457/0xa90 kernel/time/hrtimer.c:1903
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1045 [inline]
 __sysvec_apic_timer_interrupt+0xfe/0x3c0 arch/x86/kernel/apic/apic.c:1062
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
 sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1056
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:pv_native_safe_halt+0xb/0x20 arch/x86/kernel/paravirt.c:82
Code: ed 51 02 c3 cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 66 90 0f 00 2d b7 26 23 00 fb f4 <e9> d0 df 02 00 cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc 90
RSP: 0018:ffffc90000197e20 EFLAGS: 000002c2
RAX: 0000000000081291 RBX: ffffffff819607ea RCX: 0000000080000001
RDX: 0000000000000001 RSI: ffffffff8d552a69 RDI: ffffffff8ba0dae0
RBP: ffffc90000197f10 R08: ffff8880b89336db R09: 1ffff110171266db
R10: dffffc0000000000 R11: ffffed10171266dc R12: ffffffff8f5adcb0
R13: 1ffff11003951b58 R14: 0000000000000001 R15: 0000000000000001
 arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
 default_idle+0xf/0x20 arch/x86/kernel/process.c:767
 default_idle_call+0x6d/0xb0 kernel/sched/idle.c:122
 cpuidle_idle_call kernel/sched/idle.c:191 [inline]
 do_idle+0x1ba/0x4d0 kernel/sched/idle.c:332
 cpu_startup_entry+0x40/0x60 kernel/sched/idle.c:430
 start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:312
 common_startup_64+0x13e/0x147
 </TASK>
rcu: rcu_preempt kthread starved for 10500 jiffies! g15865 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:27472 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5256 [inline]
 __schedule+0x1497/0x4f60 kernel/sched/core.c:6863
 __schedule_loop kernel/sched/core.c:6945 [inline]
 schedule+0x161/0x360 kernel/sched/core.c:6960
 schedule_timeout+0x127/0x260 kernel/time/sleep_timeout.c:99
 rcu_gp_fqs_loop+0x2fd/0x1520 kernel/rcu/tree.c:2083
 rcu_gp_kthread+0x95/0x380 kernel/rcu/tree.c:2285
 kthread+0x70d/0x890 kernel/kthread.c:463
 ret_from_fork+0x508/0xa20 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 0 UID: 0 PID: 6286 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:check_kcov_mode kernel/kcov.c:194 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x33/0x60 kernel/kcov.c:217
Code: 08 e0 4a 92 65 8b 15 1c 78 8b 10 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 35 83 b9 74 16 00 00 00 74 2c 8b 91 50 16 00 00 <83> fa 02 75 21 48 8b 91 58 16 00 00 48 8b 32 48 8d 7e 01 8b 89 54
RSP: 0018:ffffc900035a7638 EFLAGS: 00000246
RAX: ffffffff81b3edc5 RBX: 1ffff11017128129 RCX: ffff88802571bc80
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc900035a7768 R08: ffffffff8f5adcb7 R09: 1ffffffff1eb5b96
R10: dffffc0000000000 R11: fffffbfff1eb5b97 R12: ffff8880b8940948
R13: dffffc0000000000 R14: ffff8880b883bac0 R15: 0000000000000001
FS:  0000555562a07500(0000) GS:ffff888126372000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f4d08d156c0 CR3: 0000000072e70000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 csd_lock_wait kernel/smp.c:342 [inline]
 smp_call_function_many_cond+0xcd5/0x1230 kernel/smp.c:877
 on_each_cpu_cond_mask+0x3b/0x80 kernel/smp.c:1043
 __flush_tlb_multi arch/x86/include/asm/paravirt.h:91 [inline]
 flush_tlb_multi arch/x86/mm/tlb.c:1382 [inline]
 flush_tlb_mm_range+0x5e2/0x1100 arch/x86/mm/tlb.c:1472
 dup_mmap+0x15f4/0x1b50 mm/mmap.c:1866
 dup_mm kernel/fork.c:1529 [inline]
 copy_mm+0x13c/0x4b0 kernel/fork.c:1581
 copy_process+0x1655/0x3940 kernel/fork.c:2221
 kernel_clone+0x21a/0x820 kernel/fork.c:2651
 __do_sys_clone kernel/fork.c:2792 [inline]
 __se_sys_clone kernel/fork.c:2776 [inline]
 __x64_sys_clone+0x187/0x1e0 kernel/fork.c:2776
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x86/0x630 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7f4d07f85e93
Code: 1f 84 00 00 00 00 00 64 48 8b 04 25 10 00 00 00 45 31 c0 31 d2 31 f6 bf 11 00 20 01 4c 8d 90 d0 02 00 00 b8 38 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 35 89 c2 85 c0 75 2c 64 48 8b 04 25 10 00 00
RSP: 002b:00007ffce8d58ed8 EFLAGS: 00000246 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f4d07f85e93
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011
RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000001
R10: 0000555562a077d0 R11: 0000000000000246 R12: 0000000000000000
R13: 00000000000927c0 R14: 000000000001f59b R15: 00007ffce8d59070
 </TASK>