From c1a6bff28cbff796bf6e7db5cf42ec9244911be2 Mon Sep 17 00:00:00 2001
From: Petr Matousek <pmatouse@redhat.com>
Date: Wed, 11 Mar 2015 12:16:09 +0100
Subject: [PATCH] kvm: x86: i8259: return initialized data on invalid-size read

If data is read from PIC with invalid access size, the return data stays
uninitialized even though success is returned.

Fix this by always initializing the data.

Signed-off-by: Petr Matousek <pmatouse@redhat.com>
Reported-by: Nadav Amit <nadav.amit@gmail.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
---
 arch/x86/kvm/i8259.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/x86/kvm/i8259.c b/arch/x86/kvm/i8259.c
index cc31f7c06d3ddc..9541ba34126b90 100644
--- a/arch/x86/kvm/i8259.c
+++ b/arch/x86/kvm/i8259.c
@@ -507,6 +507,7 @@ static int picdev_read(struct kvm_pic *s,
 		return -EOPNOTSUPP;
 
 	if (len != 1) {
+		memset(val, 0, len);
 		pr_pic_unimpl("non byte read\n");
 		return 0;
 	}