rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (1 GPs behind) idle=3fe4/1/0x4000000000000000 softirq=235463/235467 fqs=1 rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P15865/1:b..l rcu: (detected by 1, t=10505 jiffies, g=227625, q=542 ncpus=2) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 15866 Comm: syz.8.10203 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:__kasan_check_byte+0xa/0x50 mm/kasan/common.c:572 Code: 00 00 00 41 5c 41 5d e9 04 2b 00 00 0f 1f 40 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1f 40 d6 41 54 49 89 f4 55 <48> 89 fd 53 e8 9d 1e 00 00 89 c3 84 c0 74 0b 89 d8 5b 5d 41 5c c3 RSP: 0018:ffffc90000007de8 EFLAGS: 00000002 RAX: 0000000000000001 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff8b8dedb6 RDI: ffff8880b84284d8 RBP: ffff8880b84284d8 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000001 R12: ffffffff8b8dedb6 R13: 0000000000000001 R14: 0000000000000000 R15: 0000000000000000 FS: 00007fb6184606c0(0000) GS:ffff88812436d000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2f119ff8 CR3: 0000000032dde000 CR4: 00000000003526f0 DR0: ffffffffffffffff DR1: 00000000000001f8 DR2: 0000000000000002 DR3: ffffffffefffff15 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: kasan_check_byte include/linux/kasan.h:402 [inline] lock_acquire kernel/locking/lockdep.c:5842 [inline] lock_acquire+0x12a/0x370 kernel/locking/lockdep.c:5825 __raw_spin_lock_irq include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock_irq+0x36/0x50 kernel/locking/spinlock.c:174 __run_hrtimer kernel/time/hrtimer.c:1934 [inline] __hrtimer_run_queues+0x1bd/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 46 a2 56 f6 48 89 df e8 1e f2 56 f6 f7 c5 00 02 00 00 75 23 9c 58 f6 c4 02 75 37 01 00 00 00 e8 a5 bb 46 f6 65 8b 05 1e 3f 7d 08 85 c0 74 16 5b RSP: 0018:ffffc9000d26fb28 EFLAGS: 00000246 RAX: 0000000000000006 RBX: ffffffff9b1ae118 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff8df22fb5 RDI: ffffffff8c1c4180 RBP: 0000000000000286 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: ffffffff9b1ade80 R13: 0000000000000000 R14: ffffc9000d26fc80 R15: 7fffffffffffffff class_raw_spinlock_irqsave_destructor include/linux/spinlock.h:571 [inline] __do_adjtimex+0x892/0xe70 kernel/time/timekeeping.c:2871 do_adjtimex+0xa0/0x370 kernel/time/timekeeping.c:2914 do_clock_adjtime kernel/time/posix-timers.c:1154 [inline] __do_sys_clock_adjtime+0x177/0x290 kernel/time/posix-timers.c:1166 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x10b/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fb61759ce59 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:00007fb618460028 EFLAGS: 00000246 ORIG_RAX: 0000000000000131 RAX: ffffffffffffffda RBX: 00007fb617816180 RCX: 00007fb61759ce59 RDX: 0000000000000000 RSI: 0000200000000040 RDI: 0000000000000000 RBP: 00007fb617632d6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fb617816218 R14: 00007fb617816180 R15: 00007ffe528ffa78 task:syz-executor state:R running task stack:28456 pid:15865 tgid:15865 ppid:5613 task_flags:0x400040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5388 [inline] __schedule+0x1295/0x67a0 kernel/sched/core.c:7189 preempt_schedule_irq+0x50/0x90 kernel/sched/core.c:7513 irqentry_exit_to_kernel_mode_preempt include/linux/irq-entry-common.h:468 [inline] irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:539 [inline] irqentry_exit+0x205/0x7e0 kernel/entry/common.c:164 asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:__seqprop_spinlock_sequence include/linux/seqlock.h:228 [inline] RIP: 0010:read_seqbegin include/linux/seqlock.h:838 [inline] RIP: 0010:path_init+0x4e7/0x1ab0 fs/namei.c:2729 Code: 48 8b 75 08 4c 89 ff e8 87 0b 57 ff 9c 41 5c 41 81 e4 00 02 00 00 31 ff 4c 89 e6 e8 c3 23 7b ff 5a 4d 85 e4 0f 85 19 11 00 00 d4 28 7b ff 48 8b 45 a8 0f b6 00 38 45 a0 7c 08 84 c0 0f 85 92 RSP: 0018:ffffc900038d7a90 EFLAGS: 00000293 RAX: 0000000000000000 RBX: ffffc900038d7bb0 RCX: ffffffff828d963f RDX: ffff88807d592500 RSI: ffffffff828d964e RDI: ffffffff828dc8c8 RBP: ffffc900038d7b30 R08: 0000000000000007 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: ffff88807d592500 R14: ffff888026fc0c00 R15: ffff888026fc0c10 path_parentat fs/namei.c:2855 [inline] __filename_parentat+0x208/0x740 fs/namei.c:2880 filename_parentat fs/namei.c:2898 [inline] filename_create+0xbe/0x400 fs/namei.c:4931 filename_symlinkat+0xe1/0x560 fs/namei.c:5662 __do_sys_symlinkat fs/namei.c:5688 [inline] __se_sys_symlinkat fs/namei.c:5683 [inline] __x64_sys_symlinkat+0x9c/0xe0 fs/namei.c:5683 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x10b/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f0da3f9bf17 RSP: 002b:00007ffcc7ae7338 EFLAGS: 00000202 ORIG_RAX: 000000000000010a RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f0da3f9bf17 RDX: 00007f0da4033d3e RSI: 00000000ffffff9c RDI: 00007ffcc7ae73d0 RBP: 00007ffcc7ae737c R08: 0000000000000001 R09: 00000000ffffffff R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000955 R13: 00000000000927c0 R14: 000000000014e01e R15: 00007ffcc7ae73d0 rcu: rcu_preempt kthread starved for 10500 jiffies! g227625 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:26488 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: CPU: 1 UID: 0 PID: 15862 Comm: modprobe 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:csd_lock_wait kernel/smp.c:342 [inline] RIP: 0010:smp_call_function_many_cond+0x5a3/0x1700 kernel/smp.c:892 Code: e4 07 49 01 c5 41 83 c4 03 e8 39 83 0c 00 f3 90 41 0f b6 45 00 41 38 c4 7c 08 84 c0 0f 85 63 0f 00 00 8b 45 08 31 ff 83 e0 01 <41> 89 c6 89 c6 e8 c3 7d 0c 00 45 85 f6 75 d0 e8 09 83 0c 00 e8 04 RSP: 0018:ffffc900035878a8 EFLAGS: 00000202 RAX: 0000000000000001 RBX: 0000000000000000 RCX: ffffffff81fc2d8d RDX: ffff888029952500 RSI: ffffffff81fc2d67 RDI: 0000000000000000 RBP: ffff8880b8443320 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000003 R13: ffffed1017088665 R14: 0000000000000001 R15: ffff8880b853c5c0 FS: 0000000000000000(0000) GS:ffff88812446d000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f27bdf78a90 CR3: 0000000052011000 CR4: 00000000003526f0 Call Trace: on_each_cpu_cond_mask+0x40/0x90 kernel/smp.c:1057 __flush_tlb_multi arch/x86/include/asm/paravirt.h:46 [inline] flush_tlb_multi arch/x86/mm/tlb.c:1361 [inline] flush_tlb_mm_range+0x45f/0x16f0 arch/x86/mm/tlb.c:1451 tlb_flush arch/x86/include/asm/tlb.h:23 [inline] tlb_flush_mmu_tlbonly include/asm-generic/tlb.h:509 [inline] tlb_flush_mmu_tlbonly include/asm-generic/tlb.h:499 [inline] tlb_flush_mmu mm/mmu_gather.c:423 [inline] tlb_finish_mmu+0x3fe/0x810 mm/mmu_gather.c:549 exit_mmap+0x454/0xa10 mm/mmap.c:1313 __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 __do_sys_exit_group kernel/exit.c:1130 [inline] __se_sys_exit_group kernel/exit.c:1128 [inline] __x64_sys_exit_group+0x3e/0x50 kernel/exit.c:1128 x64_sys_call+0x102c/0x1530 arch/x86/include/generated/asm/syscalls_64.h:232 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x10b/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f88a01fe6c5 Code: Unable to access opcode bytes at 0x7f88a01fe69b. RSP: 002b:00007ffd6ecb7fc8 EFLAGS: 00000202 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 00007f88a02fffe8 RCX: 00007f88a01fe6c5 RDX: 00000000000000e7 RSI: ffffffffffffff88 RDI: 0000000000000001 RBP: 0000000000000001 R08: 00007ffd6ecb7f58 R09: 0000000000000000 R10: 00007ffd6ecb7df0 R11: 0000000000000202 R12: 0000000000000000 R13: 0000000000000001 R14: 00007f88a02fe680 R15: 00007f88a0300000