BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:231 in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 30, name: ktimers/1 preempt_count: 10001, expected: 0 RCU nest depth: 2, expected: 2 5 locks held by ktimers/1/30: #0: ffffffff8e25f260 (local_bh){.+.+}-{1:3}, at: __local_bh_disable_ip+0x3c/0x420 kernel/softirq.c:163 #1: ffffffff8e3c8100 (rcu_read_lock){....}-{1:3}, at: __local_bh_disable_ip+0x3c/0x420 kernel/softirq.c:163 #2: ffff8880b8726360 (&base->expiry_lock){+...}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:45 [inline] #2: ffff8880b8726360 (&base->expiry_lock){+...}-{3:3}, at: timer_base_lock_expiry kernel/time/timer.c:1502 [inline] #2: ffff8880b8726360 (&base->expiry_lock){+...}-{3:3}, at: __run_timer_base+0x120/0x9f0 kernel/time/timer.c:2384 #3: ffffffff8e3c8100 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #3: ffffffff8e3c8100 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #3: ffffffff8e3c8100 (rcu_read_lock){....}-{1:3}, at: __rt_spin_lock kernel/locking/spinlock_rt.c:50 [inline] #3: ffffffff8e3c8100 (rcu_read_lock){....}-{1:3}, at: rt_spin_lock+0x1e0/0x400 kernel/locking/spinlock_rt.c:57 #4: ffff88803913dac8 (&kvm->srcu){.?.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:187 [inline] #4: ffff88803913dac8 (&kvm->srcu){.?.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:294 [inline] #4: ffff88803913dac8 (&kvm->srcu){.?.+}-{0:0}, at: kvm_xen_set_evtchn_fast+0x1c6/0x9a0 arch/x86/kvm/xen.c:1817 irq event stamp: 13772921 hardirqs last enabled at (13772920): [] __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:187 [inline] hardirqs last enabled at (13772920): [] _raw_spin_unlock_irq+0x23/0x50 kernel/locking/spinlock.c:206 hardirqs last disabled at (13772921): [] sysvec_apic_timer_interrupt+0xe/0xc0 arch/x86/kernel/apic/apic.c:1061 softirqs last enabled at (13772906): [] ksoftirqd_run_end kernel/softirq.c:325 [inline] softirqs last enabled at (13772906): [] run_ktimerd+0x8b/0x100 kernel/softirq.c:1153 softirqs last disabled at (13772910): [] smpboot_thread_fn+0x541/0xa50 kernel/smpboot.c:160 Preemption disabled at: [<0000000000000000>] 0x0 CPU: 1 UID: 0 PID: 30 Comm: ktimers/1 Tainted: G L syzkaller #0 PREEMPT_{RT,(full)} Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 __might_resched+0x329/0x480 kernel/sched/core.c:9162 rt_read_lock+0xa9/0x4b0 kernel/locking/spinlock_rt.c:231 kvm_xen_set_evtchn_fast+0x1fc/0x9a0 arch/x86/kvm/xen.c:1819 xen_timer_callback+0x109/0x220 arch/x86/kvm/xen.c:140 __run_hrtimer kernel/time/hrtimer.c:1930 [inline] __hrtimer_run_queues+0x3bc/0xb10 kernel/time/hrtimer.c:1994 hrtimer_interrupt+0x455/0x950 kernel/time/hrtimer.c:2113 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline] __sysvec_apic_timer_interrupt+0x102/0x430 arch/x86/kernel/apic/apic.c:1067 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1061 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 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_irq include/linux/spinlock_api_smp.h:188 [inline] RIP: 0010:_raw_spin_unlock_irq+0x29/0x50 kernel/locking/spinlock.c:206 Code: 90 f3 0f 1e fa 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 8a a9 5c f6 48 89 df e8 c2 35 5d f6 e8 cd e1 88 f6 fb bf 01 00 00 00 22 c5 4f f6 65 8b 05 fb 43 77 07 85 c0 74 07 5b c3 cc cc cc cc RSP: 0018:ffffc90000a4fb30 EFLAGS: 00000206 RAX: 0000000000d22878 RBX: ffff8880b87262c0 RCX: 0000000080000001 RDX: 0000000000000002 RSI: ffffffff8d995925 RDI: 0000000000000001 RBP: ffffc90000a4fcb8 R08: ffffffff8fcf17f7 R09: 1ffffffff1f9e2fe R10: dffffc0000000000 R11: fffffbfff1f9e2ff R12: ffffc9000668fa20 R13: 1ffff92000149f80 R14: ffff8880b87262c0 R15: ffffc90000a4fc00 expire_timers kernel/time/timer.c:1798 [inline] __run_timers kernel/time/timer.c:2374 [inline] __run_timer_base+0x693/0x9f0 kernel/time/timer.c:2386 run_timer_base kernel/time/timer.c:2395 [inline] run_timer_softirq+0xb7/0x170 kernel/time/timer.c:2405 handle_softirqs+0x1de/0x6d0 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] run_ktimerd+0x69/0x100 kernel/softirq.c:1151 smpboot_thread_fn+0x541/0xa50 kernel/smpboot.c:160 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 ============================= [ BUG: Invalid wait context ] syzkaller #0 Tainted: G W L ----------------------------- ktimers/1/30 is trying to lock: ffff88803913d4d0 (&gpc->lock){+.+.}-{3:3}, at: kvm_xen_set_evtchn_fast+0x1fc/0x9a0 arch/x86/kvm/xen.c:1819 other info that might help us debug this: context-{2:2} 5 locks held by ktimers/1/30: #0: ffffffff8e25f260 (local_bh){.+.+}-{1:3}, at: __local_bh_disable_ip+0x3c/0x420 kernel/softirq.c:163 #1: ffffffff8e3c8100 (rcu_read_lock){....}-{1:3}, at: __local_bh_disable_ip+0x3c/0x420 kernel/softirq.c:163 #2: ffff8880b8726360 (&base->expiry_lock){+...}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:45 [inline] #2: ffff8880b8726360 (&base->expiry_lock){+...}-{3:3}, at: timer_base_lock_expiry kernel/time/timer.c:1502 [inline] #2: ffff8880b8726360 (&base->expiry_lock){+...}-{3:3}, at: __run_timer_base+0x120/0x9f0 kernel/time/timer.c:2384 #3: ffffffff8e3c8100 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #3: ffffffff8e3c8100 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #3: ffffffff8e3c8100 (rcu_read_lock){....}-{1:3}, at: __rt_spin_lock kernel/locking/spinlock_rt.c:50 [inline] #3: ffffffff8e3c8100 (rcu_read_lock){....}-{1:3}, at: rt_spin_lock+0x1e0/0x400 kernel/locking/spinlock_rt.c:57 #4: ffff88803913dac8 (&kvm->srcu){.?.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:187 [inline] #4: ffff88803913dac8 (&kvm->srcu){.?.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:294 [inline] #4: ffff88803913dac8 (&kvm->srcu){.?.+}-{0:0}, at: kvm_xen_set_evtchn_fast+0x1c6/0x9a0 arch/x86/kvm/xen.c:1817 stack backtrace: CPU: 1 UID: 0 PID: 30 Comm: ktimers/1 Tainted: G W L syzkaller #0 PREEMPT_{RT,(full)} Tainted: [W]=WARN, [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_lock_invalid_wait_context kernel/locking/lockdep.c:4832 [inline] check_wait_context kernel/locking/lockdep.c:4904 [inline] __lock_acquire+0xec1/0x2cf0 kernel/locking/lockdep.c:5189 lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5870 rt_read_lock+0xcc/0x4b0 kernel/locking/spinlock_rt.c:232 kvm_xen_set_evtchn_fast+0x1fc/0x9a0 arch/x86/kvm/xen.c:1819 xen_timer_callback+0x109/0x220 arch/x86/kvm/xen.c:140 __run_hrtimer kernel/time/hrtimer.c:1930 [inline] __hrtimer_run_queues+0x3bc/0xb10 kernel/time/hrtimer.c:1994 hrtimer_interrupt+0x455/0x950 kernel/time/hrtimer.c:2113 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline] __sysvec_apic_timer_interrupt+0x102/0x430 arch/x86/kernel/apic/apic.c:1067 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1061 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 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_irq include/linux/spinlock_api_smp.h:188 [inline] RIP: 0010:_raw_spin_unlock_irq+0x29/0x50 kernel/locking/spinlock.c:206 Code: 90 f3 0f 1e fa 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 8a a9 5c f6 48 89 df e8 c2 35 5d f6 e8 cd e1 88 f6 fb bf 01 00 00 00 22 c5 4f f6 65 8b 05 fb 43 77 07 85 c0 74 07 5b c3 cc cc cc cc RSP: 0018:ffffc90000a4fb30 EFLAGS: 00000206 RAX: 0000000000d22878 RBX: ffff8880b87262c0 RCX: 0000000080000001 RDX: 0000000000000002 RSI: ffffffff8d995925 RDI: 0000000000000001 RBP: ffffc90000a4fcb8 R08: ffffffff8fcf17f7 R09: 1ffffffff1f9e2fe R10: dffffc0000000000 R11: fffffbfff1f9e2ff R12: ffffc9000668fa20 R13: 1ffff92000149f80 R14: ffff8880b87262c0 R15: ffffc90000a4fc00 expire_timers kernel/time/timer.c:1798 [inline] __run_timers kernel/time/timer.c:2374 [inline] __run_timer_base+0x693/0x9f0 kernel/time/timer.c:2386 run_timer_base kernel/time/timer.c:2395 [inline] run_timer_softirq+0xb7/0x170 kernel/time/timer.c:2405 handle_softirqs+0x1de/0x6d0 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] run_ktimerd+0x69/0x100 kernel/softirq.c:1151 smpboot_thread_fn+0x541/0xa50 kernel/smpboot.c:160 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 ---------------- Code disassembly (best guess): 0: 90 nop 1: f3 0f 1e fa endbr64 5: 53 push %rbx 6: 48 89 fb mov %rdi,%rbx 9: 48 83 c7 18 add $0x18,%rdi d: 48 8b 74 24 08 mov 0x8(%rsp),%rsi 12: e8 8a a9 5c f6 call 0xf65ca9a1 17: 48 89 df mov %rbx,%rdi 1a: e8 c2 35 5d f6 call 0xf65d35e1 1f: e8 cd e1 88 f6 call 0xf688e1f1 24: fb sti 25: bf 01 00 00 00 mov $0x1,%edi * 2a: e8 22 c5 4f f6 call 0xf64fc551 <-- trapping instruction 2f: 65 8b 05 fb 43 77 07 mov %gs:0x77743fb(%rip),%eax # 0x7774431 36: 85 c0 test %eax,%eax 38: 74 07 je 0x41 3a: 5b pop %rbx 3b: c3 ret 3c: cc int3 3d: cc int3 3e: cc int3 3f: cc int3