rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P15847/1:b..l P15840/3:b..l rcu: (detected by 1, t=10502 jiffies, g=78089, q=110 ncpus=2) task:syz.1.2038 state:R running task stack:25880 pid:15840 tgid:15838 ppid:5613 task_flags:0x400140 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5388 [inline] __schedule+0x1295/0x67a0 kernel/sched/core.c:7189 preempt_schedule_common+0x42/0xc0 kernel/sched/core.c:7370 preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12 __raw_spin_unlock include/linux/spinlock_api_smp.h:169 [inline] _raw_spin_unlock+0x3e/0x50 kernel/locking/spinlock.c:190 spin_unlock include/linux/spinlock.h:390 [inline] filemap_map_pages+0x15ac/0x2140 mm/filemap.c:3942 do_fault_around mm/memory.c:5867 [inline] do_read_fault mm/memory.c:5900 [inline] do_fault+0x985/0x1750 mm/memory.c:6043 do_pte_missing mm/memory.c:4566 [inline] handle_pte_fault mm/memory.c:6427 [inline] __handle_mm_fault+0x187d/0x2a00 mm/memory.c:6565 handle_mm_fault+0x37b/0xa30 mm/memory.c:6734 faultin_page mm/gup.c:1126 [inline] __get_user_pages+0x1178/0x32a0 mm/gup.c:1428 populate_vma_page_range+0x267/0x3f0 mm/gup.c:1860 __mm_populate+0x107/0x3a0 mm/gup.c:1963 mm_populate include/linux/mm.h:4137 [inline] vm_mmap_pgoff+0x37f/0x470 mm/util.c:586 ksys_mmap_pgoff+0xe4/0x610 mm/mmap.c:606 __do_sys_mmap arch/x86/kernel/sys_x86_64.c:89 [inline] __se_sys_mmap arch/x86/kernel/sys_x86_64.c:82 [inline] __x64_sys_mmap+0x125/0x190 arch/x86/kernel/sys_x86_64.c:82 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fae9f99ce59 RSP: 002b:00007faea092d028 EFLAGS: 00000246 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 00007fae9fc15fa0 RCX: 00007fae9f99ce59 RDX: b635773f06ebbeef RSI: 0000000000b36000 RDI: 0000200000000000 RBP: 00007fae9fa32d6f R08: ffffffffffffffff R09: 0000000000000000 R10: 0000000000008031 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fae9fc16038 R14: 00007fae9fc15fa0 R15: 00007ffc7c4fb208 task:syz.4.2042 state:R running task stack:27432 pid:15847 tgid:15845 ppid:5616 task_flags:0x40044c flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5388 [inline] __schedule+0x1295/0x67a0 kernel/sched/core.c:7189 preempt_schedule_common+0x42/0xc0 kernel/sched/core.c:7370 preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12 __raw_spin_unlock include/linux/spinlock_api_smp.h:169 [inline] _raw_spin_unlock+0x3e/0x50 kernel/locking/spinlock.c:190 spin_unlock include/linux/spinlock.h:390 [inline] zap_pte_range mm/memory.c:1964 [inline] zap_pmd_range mm/memory.c:2020 [inline] zap_pud_range mm/memory.c:2048 [inline] zap_p4d_range mm/memory.c:2069 [inline] __zap_vma_range+0x16f7/0x4a30 mm/memory.c:2109 unmap_vmas+0x299/0x5f0 mm/memory.c:2178 exit_mmap+0x1ef/0xa10 mm/mmap.c:1300 __mmput+0x12a/0x410 kernel/fork.c:1178 mmput+0x67/0x80 kernel/fork.c:1201 exit_mm kernel/exit.c:582 [inline] do_exit+0x8b2/0x2af0 kernel/exit.c:964 do_group_exit+0xd5/0x2a0 kernel/exit.c:1119 get_signal+0x20ff/0x2210 kernel/signal.c:3037 arch_do_signal_or_restart+0x91/0x7e0 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:64 [inline] exit_to_user_mode_loop+0x98/0x670 kernel/entry/common.c:98 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline] do_syscall_64+0x666/0x870 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f5d21b9ce59 RSP: 002b:00007f5d1fdee0e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: 0000000000000001 RBX: 00007f5d21e15fa8 RCX: 00007f5d21b9ce59 RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007f5d21e15fac RBP: 00007f5d21e15fa0 R08: 0000000000000001 R09: 0000000000000000 R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000000 R13: 00007f5d21e16038 R14: 00007ffe59470130 R15: 00007ffe59470218 rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g78089 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=0 timer-softirq=56381 rcu: rcu_preempt kthread starved for 10502 jiffies! g78089 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:28216 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5388 [inline] __schedule+0x1295/0x67a0 kernel/sched/core.c:7189 __schedule_loop kernel/sched/core.c:7268 [inline] schedule+0xdd/0x390 kernel/sched/core.c:7283 schedule_timeout+0x127/0x280 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x1a9/0x900 kernel/rcu/tree.c:2095 rcu_gp_kthread+0x179/0x230 kernel/rcu/tree.c:2297 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158 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 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 15846 Comm: syz.9.2041 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:178 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0x2c/0x80 kernel/locking/spinlock.c:198 Code: 1e fa 55 48 89 f5 53 48 8b 74 24 10 48 89 fb 48 83 c7 18 e8 66 3d 58 f6 48 89 df e8 3e 8d 58 f6 f7 c5 00 02 00 00 75 23 9c 58 c4 02 75 37 bf 01 00 00 00 e8 55 59 48 f6 65 8b 05 3e 9d 7d 08 RSP: 0018:ffffc90000007d48 EFLAGS: 00000046 RAX: 0000000000000046 RBX: ffffffff9b361598 RCX: ffffffff81e4c063 RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffffffff9b361598 RBP: 0000000000000006 R08: 0000000000000000 R09: fffffbfff366c2b3 R10: ffffffff9b36159b R11: 0000000000000001 R12: 0000000000000002 R13: ffff888057a1b300 R14: dffffc0000000000 R15: 1ffff92000000fb0 FS: 00007f511a42a6c0(0000) GS:ffff888124383000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000000240 CR3: 00000000846e9000 CR4: 00000000003526f0 Call Trace: debug_object_activate+0x331/0x490 lib/debugobjects.c:863 debug_hrtimer_activate kernel/time/hrtimer.c:485 [inline] debug_activate kernel/time/hrtimer.c:528 [inline] enqueue_hrtimer+0x75/0x2f0 kernel/time/hrtimer.c:1109 __run_hrtimer kernel/time/hrtimer.c:1946 [inline] __hrtimer_run_queues+0x73d/0xa00 kernel/time/hrtimer.c:1994 hrtimer_interrupt+0x3e5/0x940 kernel/time/hrtimer.c:2113 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline] __sysvec_apic_timer_interrupt+0x10b/0x460 arch/x86/kernel/apic/apic.c:1067 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1061 [inline] sysvec_apic_timer_interrupt+0x9e/0xc0 arch/x86/kernel/apic/apic.c:1061 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:179 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0x31/0x80 kernel/locking/spinlock.c:198 Code: f5 53 48 8b 74 24 10 48 89 fb 48 83 c7 18 e8 66 3d 58 f6 48 89 df e8 3e 8d 58 f6 f7 c5 00 02 00 00 75 23 9c 58 f6 c4 02 75 37 01 00 00 00 e8 55 59 48 f6 65 8b 05 3e 9d 7d 08 85 c0 74 16 5b RSP: 0018:ffffc90004a87c88 EFLAGS: 00000246 RAX: 0000000000000002 RBX: ffff8880b84284c0 RCX: 0000000000000080 RDX: 0000000000000000 RSI: ffffffff8df0f560 RDI: ffffffff8c1c4480 RBP: 0000000000000287 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: fffffbfff21ae1aa R13: dffffc0000000000 R14: fcf343dd9f50dadb R15: 0000000000000002 class_raw_spinlock_irqsave_destructor include/linux/spinlock.h:571 [inline] clock_was_set+0x5d9/0x870 kernel/time/hrtimer.c:994 do_settimeofday64+0x330/0x4d0 kernel/time/timekeeping.c:1603 do_sys_settimeofday64+0x1dc/0x260 kernel/time/time.c:195 __do_sys_clock_settime kernel/time/posix-timers.c:1124 [inline] __se_sys_clock_settime kernel/time/posix-timers.c:1108 [inline] __x64_sys_clock_settime+0x1c1/0x2a0 kernel/time/posix-timers.c:1108 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f511959ce59 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f511a42a028 EFLAGS: 00000246 ORIG_RAX: 00000000000000e3 RAX: ffffffffffffffda RBX: 00007f5119815fa0 RCX: 00007f511959ce59 RDX: 0000000000000000 RSI: 0000200000000240 RDI: 0000000000000000 RBP: 00007f5119632d6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f5119816038 R14: 00007f5119815fa0 R15: 00007ffd2ec8b9b8