rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (1 GPs behind) idle=aeb4/1/0x4000000000000000 softirq=44914/44926 fqs=1 rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P8845/1:b..l rcu: (detected by 1, t=10502 jiffies, g=37145, q=504 ncpus=2) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 10267 Comm: syz.2.1211 Not tainted 6.16.0-rc1-syzkaller-00010-g2c4a1f3fe03e #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:memset_orig+0x6a/0xb0 arch/x86/lib/memset_64.S:87 Code: 47 18 48 89 47 20 48 89 47 28 48 89 47 30 48 89 47 38 48 8d 7f 40 75 d8 0f 1f 84 00 00 00 00 00 89 d1 83 e1 38 74 14 c1 e9 03 <66> 0f 1f 44 00 00 ff c9 48 89 07 48 8d 7f 08 75 f5 83 e2 07 74 0a RSP: 0018:ffffc90000007ca0 EFLAGS: 00000002 RAX: 0000000000000000 RBX: ffffffff8b8cf340 RCX: 0000000000000002 RDX: 0000000000000010 RSI: 0000000000000000 RDI: ffffc90000007cb0 RBP: ffffc90000007e90 R08: ffffc90000007cbf R09: 0000000000000000 R10: ffffc90000007cb0 R11: fffff52000000f98 R12: ffff88807e67a340 R13: dffffc0000000000 R14: 1851fc361c000000 R15: ffff8880b8627cc0 FS: 00007f95541ea6c0(0000) GS:ffff888125c86000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000555565bd1588 CR3: 00000000504be000 CR4: 00000000003526f0 DR0: 0000000000000007 DR1: 0000000000000002 DR2: 0000000000000008 DR3: 1000000100000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: debug_object_deactivate+0x36/0x250 lib/debugobjects.c:863 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 7d 66 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 f3 69 2f f6 65 8b 05 ec 43 38 07 85 c0 74 40 48 c7 04 24 0e 36 RSP: 0018:ffffc90003d77be0 EFLAGS: 00000206 RAX: 11e0e9af44138a00 RBX: 0000000000000a02 RCX: 11e0e9af44138a00 RDX: 0000000000000000 RSI: ffffffff8d96d7f4 RDI: 0000000000000001 RBP: ffffc90003d77c70 R08: ffffffff8f9fdef7 R09: 1ffffffff1f3fbde R10: dffffc0000000000 R11: fffffbfff1f3fbdf R12: dffffc0000000000 R13: 1ffff920007aef90 R14: ffffffff8e9af158 R15: 1ffff920007aef7c spin_unlock_irqrestore include/linux/spinlock.h:406 [inline] add_device_randomness+0xbf/0x100 drivers/char/random.c:951 do_settimeofday64+0x4c7/0x5e0 kernel/time/timekeeping.c:1410 __do_sys_clock_settime kernel/time/posix-timers.c:1132 [inline] __se_sys_clock_settime kernel/time/posix-timers.c:1116 [inline] __x64_sys_clock_settime+0x22c/0x280 kernel/time/posix-timers.c:1116 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: 0033:0x7f955338e929 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:00007f95541ea038 EFLAGS: 00000246 ORIG_RAX: 00000000000000e3 RAX: ffffffffffffffda RBX: 00007f95535b6080 RCX: 00007f955338e929 RDX: 0000000000000000 RSI: 0000200000000040 RDI: 0000000000000000 RBP: 00007f9553410b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f95535b6080 R15: 00007fff15a58888 task:syz-executor state:R running task stack:21800 pid:8845 tgid:8845 ppid:8835 task_flags:0x400140 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5396 [inline] __schedule+0x16a2/0x4cb0 kernel/sched/core.c:6785 preempt_schedule_notrace+0xd1/0x110 kernel/sched/core.c:7058 preempt_schedule_notrace_thunk+0x16/0x30 arch/x86/entry/thunk.S:13 rcu_is_watching+0x7f/0xb0 kernel/rcu/tree.c:746 rcu_read_lock_held_common kernel/rcu/update.c:109 [inline] rcu_read_lock_held+0x15/0x50 kernel/rcu/update.c:349 task_css include/linux/cgroup.h:453 [inline] mem_cgroup_from_task+0x9a/0x120 mm/memcontrol.c:888 count_memcg_events_mm include/linux/memcontrol.h:976 [inline] count_memcg_event_mm+0x12c/0x260 include/linux/memcontrol.h:985 mm_account_fault mm/memory.c:6266 [inline] handle_mm_fault+0x43e/0x7f0 mm/memory.c:6427 do_user_addr_fault+0xa81/0x1390 arch/x86/mm/fault.c:1336 handle_page_fault arch/x86/mm/fault.c:1476 [inline] exc_page_fault+0x76/0xf0 arch/x86/mm/fault.c:1532 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 RIP: 0033:0x7f4f5b54cd9b RSP: 002b:00007ffd8c07d770 EFLAGS: 00010206 RAX: 0000000000018a41 RBX: 0000000000008040 RCX: 0000555565bd1590 RDX: 0000000000008041 RSI: 0000555565bd95c0 RDI: 0000000000000004 RBP: 00007f4f5b784ca0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000001000 R11: 0000000000000802 R12: 0000000000008030 R13: 0000000000000076 R14: 00007f4f5b784d00 R15: 0000000000000000 rcu: rcu_preempt kthread starved for 10500 jiffies! g37145 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:5396 [inline] __schedule+0x16a2/0x4cb0 kernel/sched/core.c:6785 __schedule_loop kernel/sched/core.c:6863 [inline] schedule+0x165/0x360 kernel/sched/core.c:6878 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: 5825 Comm: syz-executor Not tainted 6.16.0-rc1-syzkaller-00010-g2c4a1f3fe03e #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:check_kcov_mode kernel/kcov.c:194 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x37/0x70 kernel/kcov.c:217 Code: 08 a0 99 92 65 8b 15 28 52 d9 10 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 35 83 b9 3c 16 00 00 00 74 2c 8b 91 18 16 00 00 <83> fa 02 75 21 48 8b 91 20 16 00 00 48 8b 32 48 8d 7e 01 8b 89 1c RSP: 0018:ffffc900048af578 EFLAGS: 00000246 RAX: ffffffff81b4da10 RBX: ffff8880b873c9c0 RCX: ffff88802a87bc00 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc900048af6e0 R08: ffffffff8f9fdef7 R09: 1ffffffff1f3fbde R10: dffffc0000000000 R11: fffffbfff1f3fbdf R12: 1ffff110170c868d R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8880b8643468 FS: 00005555777eb500(0000) GS:ffff888125d86000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000013038 CR3: 0000000076664000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000004144 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: csd_lock_wait kernel/smp.c:340 [inline] smp_call_function_many_cond+0xf80/0x12d0 kernel/smp.c:885 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 dup_mmap+0x15a0/0x1ac0 mm/mmap.c:1877 dup_mm kernel/fork.c:1477 [inline] copy_mm+0x13c/0x4b0 kernel/fork.c:1529 copy_process+0x1706/0x3c00 kernel/fork.c:2169 kernel_clone+0x224/0x7f0 kernel/fork.c:2599 __do_sys_clone kernel/fork.c:2742 [inline] __se_sys_clone kernel/fork.c:2726 [inline] __x64_sys_clone+0x18b/0x1e0 kernel/fork.c:2726 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: 0033:0x7fedcdb85193 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:00007fff2dabda08 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fedcdb85193 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000001 R10: 00005555777eb7d0 R11: 0000000000000246 R12: 0000000000000000 R13: 00000000000927c0 R14: 000000000008a492 R15: 00007fff2dabdba0