============================= [ BUG: Invalid wait context ] syzkaller #0 Tainted: G L ----------------------------- swapper/1/0 is trying to lock: ffff888059d212e0 (&gpc->lock){....}-{3:3}, at: kvm_xen_set_evtchn_fast+0x253/0xe80 arch/x86/kvm/xen.c:1820 other info that might help us debug this: context-{2:2} 1 lock held by swapper/1/0: #0: ffff888059d21840 (&kvm->srcu){.?.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:187 [inline] #0: ffff888059d21840 (&kvm->srcu){.?.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:294 [inline] #0: ffff888059d21840 (&kvm->srcu){.?.+}-{0:0}, at: kvm_xen_set_evtchn_fast+0x245/0xe80 arch/x86/kvm/xen.c:1818 stack backtrace: CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120 print_lock_invalid_wait_context kernel/locking/lockdep.c:4830 [inline] check_wait_context kernel/locking/lockdep.c:4902 [inline] __lock_acquire+0xfa4/0x2630 kernel/locking/lockdep.c:5187 lock_acquire kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x1cf/0x380 kernel/locking/lockdep.c:5825 __raw_read_lock_irqsave include/linux/rwlock_api_smp.h:172 [inline] _raw_read_lock_irqsave+0x46/0x90 kernel/locking/spinlock.c:236 kvm_xen_set_evtchn_fast+0x253/0xe80 arch/x86/kvm/xen.c:1820 xen_timer_callback+0x1db/0x2a0 arch/x86/kvm/xen.c:140 __run_hrtimer kernel/time/hrtimer.c:1785 [inline] __hrtimer_run_queues+0x1ad/0xa70 kernel/time/hrtimer.c:1849 hrtimer_interrupt+0x397/0x8c0 kernel/time/hrtimer.c:1911 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1045 [inline] __sysvec_apic_timer_interrupt+0x109/0x490 arch/x86/kernel/apic/apic.c:1062 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline] sysvec_apic_timer_interrupt+0x9e/0xc0 arch/x86/kernel/apic/apic.c:1056 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:63 Code: d8 82 02 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 eb 07 0f 00 2d 43 0c 1c 00 fb f4 bc 35 03 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90 RSP: 0018:ffffc90000177df0 EFLAGS: 00000202 RAX: 000000000018106b RBX: ffff88801e6c2480 RCX: ffffffff8b8f7c75 RDX: 0000000000000000 RSI: ffffffff8de71e08 RDI: ffffffff8c1aefa0 RBP: 0000000000000001 R08: 0000000000000001 R09: ffffed100d4a6795 R10: ffff88806a533cab R11: 0000000000000000 R12: ffffed1003cd8490 R13: 0000000000000001 R14: ffffffff90d96410 R15: 0000000000000000 arch_safe_halt arch/x86/include/asm/paravirt.h:73 [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:191 [inline] do_idle+0x35b/0x4b0 kernel/sched/idle.c:332 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:430 start_secondary+0x21d/0x2d0 arch/x86/kernel/smpboot.c:312 common_startup_64+0x13e/0x148 ---------------- Code disassembly (best guess): 0: d8 82 02 c3 cc cc fadds -0x33333cfe(%rdx) 6: cc int3 7: cc int3 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: eb 07 jmp 0x28 21: 0f 00 2d 43 0c 1c 00 verw 0x1c0c43(%rip) # 0x1c0c6b 28: fb sti 29: f4 hlt * 2a: e9 bc 35 03 00 jmp 0x335eb <-- 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