=============================
[ BUG: Invalid wait context ]
syzkaller #0 Tainted: G L
-----------------------------
swapper/0/0 is trying to lock:
ffff8880584f5bc8 (&gpc->lock){....}-{3:3}, at: kvm_xen_set_evtchn_fast+0x208/0x8d0 arch/x86/kvm/xen.c:1872
other info that might help us debug this:
context-{2:2}
locks held by swapper/0/0: 1, last CPU#0:
#0: ffff8880584f6118 (&kvm->srcu){.?.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:213 [inline]
#0: ffff8880584f6118 (&kvm->srcu){.?.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:320 [inline]
#0: ffff8880584f6118 (&kvm->srcu){.?.+}-{0:0}, at: kvm_xen_set_evtchn_fast+0x1d2/0x8d0 arch/x86/kvm/xen.c:1870
stack backtrace:
CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/07/2026
Call Trace:
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
print_lock_invalid_wait_context kernel/locking/lockdep.c:4874 [inline]
check_wait_context kernel/locking/lockdep.c:4946 [inline]
__lock_acquire+0xf5b/0x2de0 kernel/locking/lockdep.c:5238
lock_acquire+0x115/0x350 kernel/locking/lockdep.c:5942
__raw_read_lock_irqsave include/linux/rwlock_api_smp.h:174 [inline]
_raw_read_lock_irqsave+0x48/0x60 kernel/locking/spinlock.c:271
kvm_xen_set_evtchn_fast+0x208/0x8d0 arch/x86/kvm/xen.c:1872
xen_timer_callback+0x109/0x220 arch/x86/kvm/xen.c:139
__run_hrtimer kernel/time/hrtimer.c:2075 [inline]
__hrtimer_run_queues+0x371/0xa10 kernel/time/hrtimer.c:2132
hrtimer_interrupt+0x4cd/0xaa0 kernel/time/hrtimer.c:2251
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1051 [inline]
__sysvec_apic_timer_interrupt+0x102/0x430 arch/x86/kernel/apic/apic.c:1068
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline]
sysvec_apic_timer_interrupt+0xa1/0xc0 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: 1b 97 02 c3 cc cc cc cc cc cc cc 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 c3 8a 29 00 fb f4 fc 17 03 00 cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90
RSP: 0018:ffffffff8fc07ca0 EFLAGS: 00000246
RAX: 000000000045ab39 RBX: ffffffff819c9d40 RCX: 8000000000000001
RDX: 0000000000000001 RSI: ffffffff8e69c891 RDI: ffffffff8c8e7180
RBP: ffffffff8fc07d78 R08: ffff8880b8233d9b R09: 1ffff110170467b3
R10: dffffc0000000000 R11: ffffed10170467b4 R12: 0000000000000000
R13: 1ffffffff1f91e00 R14: 1ffffffff1f80f9c R15: dffffc0000000000
arch_safe_halt arch/x86/kernel/process.c:767 [inline]
default_idle+0x9/0x20 arch/x86/kernel/process.c:768
default_idle_call+0x72/0xb0 kernel/sched/idle.c:122
cpuidle_idle_call kernel/sched/idle.c:199 [inline]
do_idle+0x2e0/0x540 kernel/sched/idle.c:355
cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:454
rest_init+0x378/0x3a0 init/main.c:793
start_kernel+0x392/0x3e0 init/main.c:1251
x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310
x86_64_start_kernel+0x137/0x1b0 arch/x86/kernel/head64.c:291
common_startup_64+0x13e/0x157
----------------
Code disassembly (best guess):
0: 1b 97 02 c3 cc cc sbb -0x33333cfe(%rdi),%edx
6: cc int3
7: cc int3
8: cc int3
9: cc int3
a: cc int3
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 c3 8a 29 00 verw 0x298ac3(%rip) # 0x298aeb
28: fb sti
29: f4 hlt
* 2a: e9 fc 17 03 00 jmp 0x3182b <-- trapping instruction
2f: cc int3
30: cc int3
31: cc int3
32: cc int3
33: cc int3
34: cc int3
35: cc int3
36: cc int3
37: cc int3
38: cc int3
39: cc int3
3a: cc int3
3b: 90 nop
3c: 90 nop
3d: 90 nop
3e: 90 nop
3f: 90 nop