* [PATCH v2] KVM: x86: Fully initialize 'struct kvm_lapic_irq' in kvm_pv_kick_cpu_op()
@ 2022-07-08 12:51 Vitaly Kuznetsov
2022-07-08 14:27 ` Vitaly Kuznetsov
` (2 more replies)
0 siblings, 3 replies; 4+ messages in thread
From: Vitaly Kuznetsov @ 2022-07-08 12:51 UTC (permalink / raw)
To: kvm, Paolo Bonzini
Cc: Sean Christopherson, Wanpeng Li, Jim Mattson, linux-hyperv, linux-kernel
'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: a183b638b61c ("KVM: x86: make apic_accept_irq tracepoint more generic")
Reported-by: syzbot+d6caa905917d353f0d07@syzkaller.appspotmail.com
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
---
- Changes since v1:
Only set fields which matter for APIC_DM_REMRD and defer
initialization of the rest to the compiler [Sean].
---
arch/x86/kvm/x86.c | 18 ++++++++++--------
1 file changed, 10 insertions(+), 8 deletions(-)
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 567d13405445..6364da034462 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -9340,15 +9340,17 @@ 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);
}
--
2.35.3
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH v2] KVM: x86: Fully initialize 'struct kvm_lapic_irq' in kvm_pv_kick_cpu_op()
2022-07-08 12:51 [PATCH v2] KVM: x86: Fully initialize 'struct kvm_lapic_irq' in kvm_pv_kick_cpu_op() Vitaly Kuznetsov
@ 2022-07-08 14:27 ` Vitaly Kuznetsov
2022-07-08 15:58 ` Sean Christopherson
2022-07-14 16:09 ` Paolo Bonzini
2 siblings, 0 replies; 4+ messages in thread
From: Vitaly Kuznetsov @ 2022-07-08 14:27 UTC (permalink / raw)
To: linux-hyperv
Cc: Sean Christopherson, Wanpeng Li, Jim Mattson, linux-kernel, kvm,
Paolo Bonzini
Vitaly Kuznetsov <vkuznets@redhat.com> writes:
> '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: a183b638b61c ("KVM: x86: make apic_accept_irq tracepoint more generic")
> Reported-by: syzbot+d6caa905917d353f0d07@syzkaller.appspotmail.com
> Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
The patch was sent to linux-hyperv@ by mistake, my apologies.
--
Vitaly
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH v2] KVM: x86: Fully initialize 'struct kvm_lapic_irq' in kvm_pv_kick_cpu_op()
2022-07-08 12:51 [PATCH v2] KVM: x86: Fully initialize 'struct kvm_lapic_irq' in kvm_pv_kick_cpu_op() Vitaly Kuznetsov
2022-07-08 14:27 ` Vitaly Kuznetsov
@ 2022-07-08 15:58 ` Sean Christopherson
2022-07-14 16:09 ` Paolo Bonzini
2 siblings, 0 replies; 4+ messages in thread
From: Sean Christopherson @ 2022-07-08 15:58 UTC (permalink / raw)
To: Vitaly Kuznetsov
Cc: kvm, Paolo Bonzini, Wanpeng Li, Jim Mattson, linux-hyperv, linux-kernel
On Fri, Jul 08, 2022, Vitaly Kuznetsov wrote:
> '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: a183b638b61c ("KVM: x86: make apic_accept_irq tracepoint more generic")
> Reported-by: syzbot+d6caa905917d353f0d07@syzkaller.appspotmail.com
> Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
> ---
Reviewed-by: Sean Christopherson <seanjc@google.com>
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH v2] KVM: x86: Fully initialize 'struct kvm_lapic_irq' in kvm_pv_kick_cpu_op()
2022-07-08 12:51 [PATCH v2] KVM: x86: Fully initialize 'struct kvm_lapic_irq' in kvm_pv_kick_cpu_op() Vitaly Kuznetsov
2022-07-08 14:27 ` Vitaly Kuznetsov
2022-07-08 15:58 ` Sean Christopherson
@ 2022-07-14 16:09 ` Paolo Bonzini
2 siblings, 0 replies; 4+ messages in thread
From: Paolo Bonzini @ 2022-07-14 16:09 UTC (permalink / raw)
To: Vitaly Kuznetsov
Cc: kvm, Sean Christopherson, Wanpeng Li, Jim Mattson, linux-hyperv,
linux-kernel
Queued, thanks.
Paolo
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2022-07-14 16:10 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2022-07-08 12:51 [PATCH v2] KVM: x86: Fully initialize 'struct kvm_lapic_irq' in kvm_pv_kick_cpu_op() Vitaly Kuznetsov
2022-07-08 14:27 ` Vitaly Kuznetsov
2022-07-08 15:58 ` Sean Christopherson
2022-07-14 16:09 ` Paolo Bonzini
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.