KVM: s390: Zero initialize data structures for inject_pfault_token

__kvm_inject_pfault_token() only sets .type and .u.ext.ext_params2 of
the on-stack struct kvm_s390_irq but the full ext substructure is copied
into the cpu local variable on inject. ext_params and pad contain stale
stack values.

Interrupt delivery only uses ext_params2, so nothing leaks to the guest,
but a host user can use the migration ioctls to get to the data.

Fix by zero-initializing the irq struct.
Do the same for the inti data structure.

Fixes: 383d0b0501 ("KVM: s390: handle pending local interrupts via bitmap")
Cc: stable@vger.kernel.org
Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Message-ID: <20260805110455.7200-3-borntraeger@linux.ibm.com>
This commit is contained in:
Christian Borntraeger 2026-08-05 13:04:49 +02:00 committed by Claudio Imbrenda
parent b98014e98e
commit 4e2c7f7cbc

View File

@ -4474,8 +4474,8 @@ int kvm_s390_try_set_tod_clock(struct kvm *kvm, const struct kvm_s390_vm_tod_clo
static void __kvm_inject_pfault_token(struct kvm_vcpu *vcpu, bool start_token,
unsigned long token)
{
struct kvm_s390_interrupt inti;
struct kvm_s390_irq irq;
struct kvm_s390_interrupt inti = {};
struct kvm_s390_irq irq = {};
struct kvm_s390_interrupt_info *inti_mem = NULL;
int ret = 0;