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Commit 9f95a161 authored by Greg Kroah-Hartman's avatar Greg Kroah-Hartman
Browse files

kvm: initialize all of the kvm_debugregs structure before sending it to userspace 



commit 2c10b61421a28e95a46ab489fd56c0f442ff6952 upstream.

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.

Cc: Sean Christopherson <seanjc@google.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: <x86@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: stable <stable@kernel.org>
Reported-by: default avatarXingyuan Mo <hdthky0@gmail.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Message-Id: <20230214103304.3689213-1-gregkh@linuxfoundation.org>
Tested-by: default avatarXingyuan Mo <hdthky0@gmail.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 9f4abf20

arch/x86/kvm/x86.c

+1 −2
Original line number Diff line number Diff line
@@ -3948,12 +3948,11 @@ 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,