rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P12802/3:b..l rcu: (detected by 0, t=10506 jiffies, g=44957, q=132 ncpus=2) task:syz.1.2562 state:R running task stack:27672 pid:12802 tgid:12802 ppid:5812 task_flags:0x400040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5396 [inline] __schedule+0x116a/0x5de0 kernel/sched/core.c:6785 preempt_schedule_common+0x44/0xc0 kernel/sched/core.c:6965 preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12 __raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline] _raw_spin_unlock+0x3e/0x50 kernel/locking/spinlock.c:186 spin_unlock include/linux/spinlock.h:391 [inline] filemap_map_pages+0xe2e/0x1680 mm/filemap.c:3757 do_fault_around mm/memory.c:5568 [inline] do_read_fault mm/memory.c:5601 [inline] do_fault mm/memory.c:5744 [inline] do_pte_missing mm/memory.c:4251 [inline] handle_pte_fault mm/memory.c:6089 [inline] __handle_mm_fault+0x3b3b/0x5490 mm/memory.c:6232 handle_mm_fault+0x589/0xd10 mm/memory.c:6401 do_user_addr_fault+0x60c/0x1370 arch/x86/mm/fault.c:1336 handle_page_fault arch/x86/mm/fault.c:1476 [inline] exc_page_fault+0x5c/0xb0 arch/x86/mm/fault.c:1532 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 RIP: 0033:0x7f3b7da6ec8d RSP: 002b:00007fffc877c490 EFLAGS: 00010202 RAX: 000000110c2dc000 RBX: 00007f3b7e8e5720 RCX: 0000000000000007 RDX: 000000000000043e RSI: 0000000000002510 RDI: 0000000000000080 RBP: ffffffff81a9443e R08: 00007f3b7ddb6038 R09: 00007f3b7dda2000 R10: 00007f3b7d1ff008 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: ffffffff81a94309 R15: 000000000000130b rcu: rcu_preempt kthread timer wakeup didn't happen for 10505 jiffies! g44957 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=1 timer-softirq=24047 rcu: rcu_preempt kthread starved for 10506 jiffies! g44957 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:27672 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5396 [inline] __schedule+0x116a/0x5de0 kernel/sched/core.c:6785 __schedule_loop kernel/sched/core.c:6863 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6878 schedule_timeout+0x123/0x290 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x1ea/0xb00 kernel/rcu/tree.c:2054 rcu_gp_kthread+0x270/0x380 kernel/rcu/tree.c:2256 kthread+0x3c2/0x780 kernel/kthread.c:464 ret_from_fork+0x5d4/0x6f0 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: Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 12801 Comm: syz.2.2560 Not tainted 6.16.0-rc2-syzkaller-00269-g11313e2f7812 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:__lock_acquire+0xd1/0x1c90 kernel/locking/lockdep.c:5110 Code: 4c 24 10 44 8b 4c 24 28 48 85 c0 0f 84 7f 03 00 00 44 8b 2d 31 e8 43 19 45 85 ed 41 0f 94 c4 eb 1b c7 04 24 00 00 00 00 eb 9e <89> d8 0f 87 a8 15 00 00 49 8b 44 c7 08 48 85 c0 74 ae 8b 9d e8 0a RSP: 0018:ffffc90000a08cf0 EFLAGS: 00000097 RAX: ffff8880b8427c01 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff8880b8527c98 RBP: ffff888058692440 R08: 0000000000000001 R09: 0000000000000001 R10: 0000000000000001 R11: 0000000000000001 R12: 00000000b8427c01 R13: 0000000000000000 R14: 0000000000000000 R15: ffff8880b8527c98 FS: 00007fde23ed66c0(0000) GS:ffff888124853000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fff17615cc0 CR3: 000000007db3c000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_acquire kernel/locking/lockdep.c:5871 [inline] lock_acquire+0x179/0x350 kernel/locking/lockdep.c:5828 __raw_spin_lock_irq include/linux/spinlock_api_smp.h:119 [inline] _raw_spin_lock_irq+0x36/0x50 kernel/locking/spinlock.c:170 __run_hrtimer kernel/time/hrtimer.c:1765 [inline] __hrtimer_run_queues+0x2bc/0xad0 kernel/time/hrtimer.c:1825 hrtimer_interrupt+0x397/0x8e0 kernel/time/hrtimer.c:1887 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1039 [inline] __sysvec_apic_timer_interrupt+0x108/0x3f0 arch/x86/kernel/apic/apic.c:1056 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline] sysvec_apic_timer_interrupt+0x9f/0xc0 arch/x86/kernel/apic/apic.c:1050 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:finish_task_switch.isra.0+0x22a/0xc10 kernel/sched/core.c:5264 Code: fb 09 00 00 44 8b 05 a9 6d 1e 0f 45 85 c0 0f 85 be 01 00 00 4c 89 e7 e8 a4 f6 ff ff e8 2f 0f 3a 00 fb 65 48 8b 1d 5e f2 42 12 <48> 8d bb 18 16 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 RSP: 0018:ffffc90003d0f6f8 EFLAGS: 00000202 RAX: 0000000000006037 RBX: ffff888058692440 RCX: ffffffff81c3ebdf RDX: 0000000000000000 RSI: ffffffff8de1a430 RDI: ffffffff8c157960 RBP: ffffc90003d0f740 R08: 0000000000000001 R09: 0000000000000001 R10: ffffffff90a81957 R11: 0000000000000001 R12: ffff8880b853a2c0 R13: ffff888076220000 R14: 0000000000000001 R15: ffff8880b853b130 context_switch kernel/sched/core.c:5399 [inline] __schedule+0x1172/0x5de0 kernel/sched/core.c:6785 __schedule_loop kernel/sched/core.c:6863 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6878 schedule_timeout+0x257/0x290 kernel/time/sleep_timeout.c:75 do_wait_for_common kernel/sched/completion.c:95 [inline] __wait_for_common+0x2fc/0x4e0 kernel/sched/completion.c:116 rdmsr_safe_on_cpu+0x1dc/0x210 arch/x86/lib/msr-smp.c:181 msr_read+0x19d/0x250 arch/x86/kernel/msr.c:66 vfs_read+0x1e1/0xc60 fs/read_write.c:570 ksys_read+0x12a/0x250 fs/read_write.c:715 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fde22f8e929 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:00007fde23ed6038 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 00007fde231b5fa0 RCX: 00007fde22f8e929 RDX: 0000000000019000 RSI: 0000200000032680 RDI: 0000000000000007 RBP: 00007fde23010b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fde231b5fa0 R15: 00007ffc4dffd028