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authorAvi Kivity <avi@redhat.com>2009-10-04 16:45:13 +0200
committerAvi Kivity <avi@redhat.com>2009-10-04 17:04:16 +0200
commit6a54435560efdab1a08f429a954df4d6c740bddf (patch)
treef2141a331095cf2e7d3e1e5a14f2a7c264eaf923
parenteb5109e311b5152c0614a28d7d615d087f268f19 (diff)
KVM: Prevent overflow in KVM_GET_SUPPORTED_CPUID
The number of entries is multiplied by the entry size, which can overflow on 32-bit hosts. Bound the entry count instead. Reported-by: David Wagner <daw@cs.berkeley.edu> Cc: stable@kernel.org Signed-off-by: Avi Kivity <avi@redhat.com>
-rw-r--r--arch/x86/kvm/x86.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index be451ee4424..9b9695322f5 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -1591,6 +1591,8 @@ static int kvm_dev_ioctl_get_supported_cpuid(struct kvm_cpuid2 *cpuid,
if (cpuid->nent < 1)
goto out;
+ if (cpuid->nent > KVM_MAX_CPUID_ENTRIES)
+ cpuid->nent = KVM_MAX_CPUID_ENTRIES;
r = -ENOMEM;
cpuid_entries = vmalloc(sizeof(struct kvm_cpuid_entry2) * cpuid->nent);
if (!cpuid_entries)