Date:   Mon, 6 Dec 2021 17:02:01 +0000
From:   Sean Christopherson <seanjc@google.com>
To:     Ameer Hamza <amhamza.mgc@gmail.com>
Cc:     vkuznets@redhat.com, kvm@vger.kernel.org,
        linux-kernel@vger.kernel.org, pbonzini@redhat.com,
        wanpengli@tencent.com, jmattson@google.com, joro@8bytes.org,
        tglx@linutronix.de, mingo@redhat.com, bp@alien8.de,
        dave.hansen@linux.intel.com, x86@kernel.org, hpa@zytor.com
Subject: Re: [PATCH v3] KVM: x86: fix for missing initialization of return
 status variable
Message-ID: <Ya5CCU0zf+MzMwcX@google.com>
References: <20211206160813.GA37599@hamza-OptiPlex-7040>
 <20211206164503.135917-1-amhamza.mgc@gmail.com>
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On Mon, Dec 06, 2021, Ameer Hamza wrote:
> If undefined ioctl number is passed to the kvm_vcpu_ioctl_device_attr
> ioctl, we should trigger KVM_BUG_ON() and return with EIO to silent
> coverity warning.
> 
> Addresses-Coverity: 1494124 ("Uninitialized scalar variable")
> Signed-off-by: Ameer Hamza <amhamza.mgc@gmail.com>
> ---
> Changes in v3:
> Added KVM_BUG_ON() as default case and returned -EIO
> ---
>  arch/x86/kvm/x86.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
> index e0aa4dd53c7f..b37068f847ff 100644
> --- a/arch/x86/kvm/x86.c
> +++ b/arch/x86/kvm/x86.c
> @@ -5019,6 +5019,9 @@ static int kvm_vcpu_ioctl_device_attr(struct kvm_vcpu *vcpu,
>  	case KVM_SET_DEVICE_ATTR:
>  		r = kvm_arch_tsc_set_attr(vcpu, &attr);
>  		break;
> +	default:
> +		KVM_BUG_ON(1, vcpu->kvm);
> +		r = -EIO;

At least have a

		break;

if we're going to be pedantic about things.

>  	}
>  
>  	return r;
> -- 
> 2.25.1
>