rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (0 ticks this GP) idle=29e4/1/0x4000000000000000 softirq=98820/98820 fqs=0 (detected by 1, t=10502 jiffies, g=181033, q=22 ncpus=2) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 22290 Comm: modprobe Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 RIP: 0010:lock_acquire+0x25c/0x4a0 kernel/locking/lockdep.c:5666 Code: 08 00 00 00 00 65 48 8b 04 25 28 00 00 00 48 3b 84 24 c0 00 00 00 0f 85 f8 00 00 00 48 8d 65 d8 5b 41 5c 41 5d 41 5e 41 5f 5d 0f 0b e9 57 fe ff ff 65 8b 05 85 37 9e 7e 85 c0 75 ad 65 8b 05 RSP: 0018:ffffc90000007bf0 EFLAGS: 00000046 RAX: 0ee265a25df1d000 RBX: ffffffff96ec5cf8 RCX: 0ee265a25df1d000 RDX: 0000000000000000 RSI: ffffffff8a8c2c20 RDI: ffffffff8adf2060 RBP: ffffc90000007c88 R08: dffffc0000000000 R09: 1ffffffff215fe48 R10: dffffc0000000000 R11: fffffbfff215fe49 R12: dffffc0000000000 R13: dffffc0000000000 R14: 0000000000000802 R15: 1ffff92000000f80 FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ff57a3f5e9c CR3: 0000000054e97000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xb0/0x100 kernel/locking/spinlock.c:162 debug_object_activate+0x68/0x4f0 lib/debugobjects.c:698 debug_hrtimer_activate kernel/time/hrtimer.c:448 [inline] debug_activate kernel/time/hrtimer.c:502 [inline] enqueue_hrtimer+0x37/0x410 kernel/time/hrtimer.c:1097 __run_hrtimer kernel/time/hrtimer.c:1768 [inline] __hrtimer_run_queues+0x687/0xd50 kernel/time/hrtimer.c:1815 hrtimer_interrupt+0x3c5/0x9c0 kernel/time/hrtimer.c:1877 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1107 [inline] __sysvec_apic_timer_interrupt+0x153/0x5a0 arch/x86/kernel/apic/apic.c:1124 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline] sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1118 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691 RIP: 0010:__sanitizer_cov_trace_const_cmp4+0x7e/0x80 kernel/kcov.c:315 Code: 8d 52 28 4d 39 ca 77 22 89 ff 89 f6 49 ff c0 4c 89 01 48 c7 44 11 08 05 00 00 00 48 89 7c 11 10 48 89 74 11 18 48 89 44 11 20 90 48 8b 04 24 65 48 8b 0d b4 ef 7f 7e 65 8b 15 b5 ef 7f 7e 81 RSP: 0018:ffffc90003a47778 EFLAGS: 00000293 RAX: ffffffff81ddc7aa RBX: 0000000000000000 RCX: 0000000000000000 RDX: ffff888058049e00 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: ffff888018e1b30b R09: 1ffff110031c3661 R10: dffffc0000000000 R11: ffffed10031c3662 R12: ffff888018e1b308 R13: 0000000000000000 R14: ffff888018e1b2c8 R15: 1ffffffff1987318 page_table_check_clear+0x24a/0x6b0 mm/page_table_check.c:86 ptep_get_and_clear_full arch/x86/include/asm/jump_label.h:-1 [inline] zap_pte_range mm/memory.c:1433 [inline] zap_pmd_range mm/memory.c:1572 [inline] zap_pud_range mm/memory.c:1601 [inline] zap_p4d_range mm/memory.c:1622 [inline] unmap_page_range+0x192d/0x2500 mm/memory.c:1643 unmap_vmas+0x260/0x390 mm/memory.c:1728 exit_mmap+0x20d/0x960 mm/mmap.c:3250 __mmput+0x118/0x3c0 kernel/fork.c:1206 exit_mm+0x25a/0x360 kernel/exit.c:566 do_exit+0x905/0x2480 kernel/exit.c:868 do_group_exit+0x217/0x2d0 kernel/exit.c:1024 __do_sys_exit_group kernel/exit.c:1035 [inline] __se_sys_exit_group kernel/exit.c:1033 [inline] __x64_sys_exit_group+0x3b/0x40 kernel/exit.c:1033 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f3fcafdc6c5 Code: Unable to access opcode bytes at 0x7f3fcafdc69b. RSP: 002b:00007ffcb03e0088 EFLAGS: 00000202 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 00007f3fcb0ddfe8 RCX: 00007f3fcafdc6c5 RDX: 00000000000000e7 RSI: ffffffffffffff88 RDI: 0000000000000001 RBP: 0000000000000001 R08: 00007ffcb03e0018 R09: 0000000000000000 R10: 00007ffcb03dfeb0 R11: 0000000000000202 R12: 0000000000000000 R13: 0000000000000001 R14: 00007f3fcb0dc680 R15: 00007f3fcb0de000 rcu: rcu_preempt kthread starved for 10502 jiffies! g181033 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:26416 pid:16 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5245 [inline] __schedule+0x11d1/0x40e0 kernel/sched/core.c:6562 schedule+0xb9/0x180 kernel/sched/core.c:6638 schedule_timeout+0x184/0x2d0 kernel/time/timer.c:2168 rcu_gp_fqs_loop+0x303/0x1340 kernel/rcu/tree.c:1706 rcu_gp_kthread+0x99/0x3b0 kernel/rcu/tree.c:1905 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 rcu: Stack dump where RCU GP kthread last ran: CPU: 1 PID: 22296 Comm: syz.2.4732 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 RIP: 0010:csd_lock_wait kernel/smp.c:424 [inline] RIP: 0010:smp_call_function_many_cond+0xea2/0x1290 kernel/smp.c:998 Code: 00 00 00 41 8b 1f 89 de 83 e6 01 31 ff e8 f6 f6 0a 00 83 e3 01 48 bb 00 00 00 00 00 fc ff df 75 07 e8 82 f3 0a 00 eb 37 f3 90 <41> 0f b6 04 1c 84 c0 75 10 41 f7 07 01 00 00 00 74 1e e8 67 f3 0a RSP: 0018:ffffc900039e7ac0 EFLAGS: 00000246 RAX: ffffffff81778839 RBX: dffffc0000000000 RCX: 0000000000080000 RDX: ffffc900134bc000 RSI: 000000000007ffff RDI: 0000000000080000 RBP: ffffc900039e7c10 R08: ffff8880b8f3bbd7 R09: 1ffff110171e777a R10: dffffc0000000000 R11: ffffed10171e777b R12: 1ffff110171c8601 R13: ffff8880b8f3bbc0 R14: 0000000000000000 R15: ffff8880b8e43008 FS: 00007f6fe98b76c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2e61fff8 CR3: 000000007e2d5000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: clock_was_set+0x8ac/0x9a0 kernel/time/hrtimer.c:988 do_settimeofday64+0x5b6/0x760 kernel/time/timekeeping.c:1345 __do_sys_clock_settime kernel/time/posix-timers.c:1125 [inline] __se_sys_clock_settime kernel/time/posix-timers.c:1113 [inline] __x64_sys_clock_settime+0x25a/0x2a0 kernel/time/posix-timers.c:1113 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f6fe899ce59 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:00007f6fe98b7028 EFLAGS: 00000246 ORIG_RAX: 00000000000000e3 RAX: ffffffffffffffda RBX: 00007f6fe8c15fa0 RCX: 00007f6fe899ce59 RDX: 0000000000000000 RSI: 0000200000000240 RDI: 0000000000000000 RBP: 00007f6fe8a32d6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f6fe8c16038 R14: 00007f6fe8c15fa0 R15: 00007ffc4d78c3d8