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| author | Paolo Bonzini <pbonzini@redhat.com> | 2019-12-04 10:28:54 +0100 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2019-12-10 18:01:34 +0000 |
| commit | 21377f88c2757c6ee3e28407fb1c44b4bdf7e6b2 (patch) | |
| tree | 8bd3314300ad568987e82ed5e20c980c9c296a68 | |
| parent | 77251fec285eebe2258e81e643820428b92a68a6 (diff) | |
| download | linux-21377f88c2757c6ee3e28407fb1c44b4bdf7e6b2.tar.gz linux-21377f88c2757c6ee3e28407fb1c44b4bdf7e6b2.tar.bz2 linux-21377f88c2757c6ee3e28407fb1c44b4bdf7e6b2.zip | |
KVM: x86: fix out-of-bounds write in KVM_GET_EMULATED_CPUID (CVE-2019-19332)
commit 433f4ba1904100da65a311033f17a9bf586b287e upstream.
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>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
| -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 90ad3c2db24a..66062325d4b7 100644 --- a/arch/x86/kvm/cpuid.c +++ b/arch/x86/kvm/cpuid.c @@ -327,7 +327,7 @@ static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function, r = -E2BIG; - if (*nent >= maxnent) + if (WARN_ON(*nent >= maxnent)) goto out; do_cpuid_1_ent(entry, function, index); @@ -599,6 +599,9 @@ out: static int do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 func, u32 idx, int *nent, int maxnent, unsigned int type) { + if (*nent >= maxnent) + return -E2BIG; + if (type == KVM_GET_EMULATED_CPUID) return __do_cpuid_ent_emulated(entry, func, idx, nent, maxnent); |