From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dan Carpenter Date: Fri, 23 Jan 2015 14:32:32 +0000 Subject: [patch] KVM: always initialize *pdata in get_msr() Message-Id: <20150123143232.GA4298@mwanda> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Gleb Natapov Cc: Paolo Bonzini , Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , x86@kernel.org, kvm@vger.kernel.org, kernel-janitors@vger.kernel.org Smatch complains that there are some paths where we use uninitialized data in em_sysenter(). arch/x86/kvm/emulate.c:2410 em_sysenter() error: potentially using uninitialized 'msr_data'. A couple examples of paths which don't set "pdata" are found in get_msr_hyperv() and kvm_x2apic_msr_read(). I looked at this code and it seems like setting it to zero is a common default behaviour. Signed-off-by: Dan Carpenter --- >From static analysis only, not from real life. diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index a17d848..f0e30d2 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -3063,6 +3063,8 @@ static int svm_get_msr(struct kvm_vcpu *vcpu, unsigned ecx, u64 *data) { struct vcpu_svm *svm = to_svm(vcpu); + *data = 0; + switch (ecx) { case MSR_IA32_TSC: { *data = svm->vmcb->control.tsc_offset + diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index ce35071..3bdb9ca 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -2544,6 +2544,7 @@ static int vmx_get_msr(struct kvm_vcpu *vcpu, u32 msr_index, u64 *pdata) printk(KERN_ERR "BUG: get_msr called with NULL pdata\n"); return -EINVAL; } + *pdata = 0; switch (msr_index) { #ifdef CONFIG_X86_64