------------[ cut here ]------------ UBSAN: array-index-out-of-bounds in kernel/locking/qspinlock.h:68:9 index 16382 is out of range for type 'long unsigned int [8]' CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted syzkaller #0 PREEMPT(lazy) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120 ubsan_epilogue+0xa/0x30 lib/ubsan.c:233 __ubsan_handle_out_of_bounds+0xcc/0xf0 lib/ubsan.c:455 decode_tail kernel/locking/qspinlock.h:68 [inline] __pv_queued_spin_lock_slowpath+0xbd7/0xc00 kernel/locking/qspinlock.c:285 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt-spinlock.h:35 [inline] queued_spin_lock_slowpath arch/x86/include/asm/paravirt-spinlock.h:66 [inline] queued_spin_lock include/asm-generic/qspinlock.h:114 [inline] do_raw_spin_lock+0x1e0/0x260 kernel/locking/spinlock_debug.c:116 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock_irqsave+0x42/0x60 kernel/locking/spinlock.c:166 complete_with_flags kernel/sched/completion.c:25 [inline] complete+0x1d/0x200 kernel/sched/completion.c:52 transfer drivers/usb/gadget/udc/dummy_hcd.c:1527 [inline] dummy_timer+0x121c/0x36c0 drivers/usb/gadget/udc/dummy_hcd.c:1989 __run_hrtimer kernel/time/hrtimer.c:2032 [inline] __hrtimer_run_queues+0x462/0x9c0 kernel/time/hrtimer.c:2096 hrtimer_run_softirq+0x17d/0x2c0 kernel/time/hrtimer.c:2113 handle_softirqs+0x1dd/0x990 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0x160/0x210 kernel/softirq.c:735 irq_exit_rcu+0x9/0x30 kernel/softirq.c:752 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline] sysvec_apic_timer_interrupt+0x8f/0xb0 arch/x86/kernel/apic/apic.c:1062 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:64 Code: c0 ac 01 c3 cc cc cc cc 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 03 ef 0b 00 fb f4 7c f6 02 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90 RSP: 0018:ffffc9000013fe10 EFLAGS: 00000246 RAX: 00000000000179a4 RBX: ffff8881022d9e00 RCX: ffffffff877a98e5 RDX: 0000000000000001 RSI: ffffffff87b15000 RDI: ffffffff818a31a7 RBP: ffffed102045b3c0 R08: 0000000000000000 R09: ffffed103eae670d R10: ffff8881f573386b R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 1ffff92000027fc6 R15: dffffc0000000000 arch_safe_halt arch/x86/include/asm/paravirt.h:62 [inline] default_idle+0x9/0x10 arch/x86/kernel/process.c:767 default_idle_call+0x6c/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:199 [inline] do_idle+0x3a7/0x5b0 kernel/sched/idle.c:355 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:454 start_secondary+0x21d/0x2d0 arch/x86/kernel/smpboot.c:312 common_startup_64+0x13e/0x158 ---[ end trace ]--- ---------------- Code disassembly (best guess): 0: c0 ac 01 c3 cc cc cc shrb $0xcc,-0x3333333d(%rcx,%rax,1) 7: cc 8: 0f 1f 00 nopl (%rax) b: 90 nop c: 90 nop d: 90 nop e: 90 nop f: 90 nop 10: 90 nop 11: 90 nop 12: 90 nop 13: 90 nop 14: 90 nop 15: 90 nop 16: 90 nop 17: 90 nop 18: 90 nop 19: 90 nop 1a: 90 nop 1b: f3 0f 1e fa endbr64 1f: 66 90 xchg %ax,%ax 21: 0f 00 2d 03 ef 0b 00 verw 0xbef03(%rip) # 0xbef2b 28: fb sti 29: f4 hlt * 2a: e9 7c f6 02 00 jmp 0x2f6ab <-- trapping instruction 2f: 66 2e 0f 1f 84 00 00 cs nopw 0x0(%rax,%rax,1) 36: 00 00 00 39: 66 90 xchg %ax,%ax 3b: 90 nop 3c: 90 nop 3d: 90 nop 3e: 90 nop 3f: 90 nop