On 2/14/23 11:33, Greg Kroah-Hartman wrote:
When calling the KVM_GET_DEBUGREGS ioctl, on some configurations, there
might be some unitialized portions of the kvm_debugregs structure that
could be copied to userspace. Prevent this as is done in the other kvm
ioctls, by setting the whole structure to 0 before copying anything into
it.
Bonus is that this reduces the lines of code as the explicit flag
setting and reserved space zeroing out can be removed.
Queued, thanks!
Paolo
Cc: Sean Christopherson <seanjc@xxxxxxxxxx>
Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
Cc: <x86@xxxxxxxxxx>
Cc: "H. Peter Anvin" <hpa@xxxxxxxxx>
Cc: stable <stable@xxxxxxxxxx>
Reported-by: Xingyuan Mo <hdthky0@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/x86/kvm/x86.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index da4bbd043a7b..50a95c8082fa 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -5254,12 +5254,11 @@ static void kvm_vcpu_ioctl_x86_get_debugregs(struct kvm_vcpu *vcpu,
{
unsigned long val;
+ memset(dbgregs, 0, sizeof(*dbgregs));
memcpy(dbgregs->db, vcpu->arch.db, sizeof(vcpu->arch.db));
kvm_get_dr(vcpu, 6, &val);
dbgregs->dr6 = val;
dbgregs->dr7 = vcpu->arch.dr7;
- dbgregs->flags = 0;
- memset(&dbgregs->reserved, 0, sizeof(dbgregs->reserved));
}
static int kvm_vcpu_ioctl_x86_set_debugregs(struct kvm_vcpu *vcpu,
