From 1b2ca42267fe8c4e909312f2b83dfef882cf6234 Mon Sep 17 00:00:00 2001
From: Borislav Petkov <bp@suse.de>
Date: Wed, 6 Nov 2013 15:46:02 +0100
Subject: [PATCH] kvm, cpuid: Fix sparse warning
We need to copy padding to kernel space first before looking at it.
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
---
arch/x86/kvm/cpuid.c | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index 8f66fba804e4..c6976257eff5 100644
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -564,6 +564,7 @@ static bool sanity_check_entries(struct kvm_cpuid_entry2 __user *entries,
__u32 num_entries, unsigned int ioctl_type)
{
int i;
+ __u32 pad[3];
if (ioctl_type != KVM_GET_EMULATED_CPUID)
return false;
@@ -577,9 +578,10 @@ static bool sanity_check_entries(struct kvm_cpuid_entry2 __user *entries,
* sheds a tear.
*/
for (i = 0; i < num_entries; i++) {
- if (entries[i].padding[0] ||
- entries[i].padding[1] ||
- entries[i].padding[2])
+ if (copy_from_user(pad, entries[i].padding, sizeof(pad)))
+ return true;
+
+ if (pad[0] || pad[1] || pad[2])
return true;
}
return false;
--
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