KVM: x86: fix out-of-bounds write in KVM_GET_EMULATED_CPUID (CVE-2019-19332) (433f4ba1) · Commits · 戴 / test

The bounds check was present in KVM_GET_SUPPORTED_CPUID but not KVM_GET_EMULATED_CPUID. Reported-by:

<syzbot+e3f4897236c4eeb8af4f@syzkaller.appspotmail.com> Fixes: ("kvm: Emulate MOVBE", 2013-10-29) Signed-off-by:

arch/x86/kvm/cpuid.c

+4 −1

Original line number	Diff line number	Diff line
		@@ -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);