Commit 8a414f94 authored by Vitaly Kuznetsov's avatar Vitaly Kuznetsov Committed by Paolo Bonzini
Browse files

KVM: x86: Fully initialize 'struct kvm_lapic_irq' in kvm_pv_kick_cpu_op() 



'vector' and 'trig_mode' fields of 'struct kvm_lapic_irq' are left
uninitialized in kvm_pv_kick_cpu_op(). While these fields are normally
not needed for APIC_DM_REMRD, they're still referenced by
__apic_accept_irq() for trace_kvm_apic_accept_irq(). Fully initialize
the structure to avoid consuming random stack memory.

Fixes: a183b638 ("KVM: x86: make apic_accept_irq tracepoint more generic")
Reported-by: default avatar <syzbot+d6caa905917d353f0d07@syzkaller.appspotmail.com>
Signed-off-by: default avatarVitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: default avatarSean Christopherson <seanjc@google.com>
Message-Id: <20220708125147.593975-1-vkuznets@redhat.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent cca3f338

arch/x86/kvm/x86.c

+10 −8
Original line number Diff line number Diff line
@@ -9143,15 +9143,17 @@ static int kvm_pv_clock_pairing(struct kvm_vcpu *vcpu, gpa_t paddr, 
 */

static void kvm_pv_kick_cpu_op(struct kvm *kvm, int apicid)

{

	struct kvm_lapic_irq lapic_irq;



	lapic_irq.shorthand = APIC_DEST_NOSHORT;

	lapic_irq.dest_mode = APIC_DEST_PHYSICAL;

	lapic_irq.level = 0;

	lapic_irq.dest_id = apicid;

	lapic_irq.msi_redir_hint = false;

	/*

	 * All other fields are unused for APIC_DM_REMRD, but may be consumed by

	 * common code, e.g. for tracing. Defer initialization to the compiler.

	 */

	struct kvm_lapic_irq lapic_irq = {

		.delivery_mode = APIC_DM_REMRD,

		.dest_mode = APIC_DEST_PHYSICAL,

		.shorthand = APIC_DEST_NOSHORT,

		.dest_id = apicid,

	};



	lapic_irq.delivery_mode = APIC_DM_REMRD;

	kvm_irq_delivery_to_apic(kvm, NULL, &lapic_irq, NULL);

}