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| author | Paolo Bonzini <pbonzini@redhat.com> | 2019-12-04 12:28:54 +0300 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2019-12-04 14:14:41 +0300 |
| commit | 433f4ba1904100da65a311033f17a9bf586b287e (patch) | |
| tree | aa0ec5e38b98fe7835f354af7af331ec96b55876 | |
| parent | 3525d0ccd92c760d22b8ee26f484fb7e9941c99c (diff) | |
| download | linux-433f4ba1904100da65a311033f17a9bf586b287e.tar.xz | |
KVM: x86: fix out-of-bounds write in KVM_GET_EMULATED_CPUID (CVE-2019-19332)
The bounds check was present in KVM_GET_SUPPORTED_CPUID but not
KVM_GET_EMULATED_CPUID.
Reported-by: syzbot+e3f4897236c4eeb8af4f@syzkaller.appspotmail.com
Fixes: 84cffe499b94 ("kvm: Emulate MOVBE", 2013-10-29)
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| -rw-r--r-- | arch/x86/kvm/cpuid.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c index 813a4d2e5c0c..cfafa320a8cf 100644 --- a/arch/x86/kvm/cpuid.c +++ b/arch/x86/kvm/cpuid.c @@ -504,7 +504,7 @@ static inline int __do_cpuid_func(struct kvm_cpuid_entry2 *entry, u32 function, r = -E2BIG; - if (*nent >= maxnent) + if (WARN_ON(*nent >= maxnent)) goto out; do_host_cpuid(entry, function, 0); @@ -815,6 +815,9 @@ out: static int do_cpuid_func(struct kvm_cpuid_entry2 *entry, u32 func, int *nent, int maxnent, unsigned int type) { + if (*nent >= maxnent) + return -E2BIG; + if (type == KVM_GET_EMULATED_CPUID) return __do_cpuid_func_emulated(entry, func, nent, maxnent); |