KVM: fix cpuid E2BIG handling for extended request types

If we run out of cpuid entries for extended request types
we should return -E2BIG, just like we do for the standard
request types.

Signed-off-by: Mark McLoughlin <markmc@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

1 files changed, 4 insertions, 0 deletions

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index a93ba37eb52c..25a1c5739dfc 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -1506,6 +1506,10 @@ static int kvm_dev_ioctl_get_supported_cpuid(struct kvm_cpuid2 *cpuid,
         for (func = 0x80000001; func <= limit && nent < cpuid->nent; ++func)
                 do_cpuid_ent(&cpuid_entries[nent], func, 0,
                              &nent, cpuid->nent);
+        r = -E2BIG;
+        if (nent >= cpuid->nent)
+                goto out_free;
+
         r = -EFAULT;
         if (copy_to_user(entries, cpuid_entries,
                          nent * sizeof(struct kvm_cpuid_entry2)))