Re: [PATCH v4 1/6] kvm: svm: Fix gctx page leak on invalid inputs

[Tom Lendacky]

On 11/4/24 19:05, Dionna Glaze wrote:
> Ensure that snp gctx page allocation is adequately deallocated on
> failure during snp_launch_start.
> 
> Fixes: 136d8bc931c8 ("KVM: SEV: Add KVM_SEV_SNP_LAUNCH_START command")
> 
> CC: Sean Christopherson <seanjc@xxxxxxxxxx>
> CC: Paolo Bonzini <pbonzini@xxxxxxxxxx>
> CC: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> CC: Ingo Molnar <mingo@xxxxxxxxxx>
> CC: Borislav Petkov <bp@xxxxxxxxx>
> CC: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
> CC: Ashish Kalra <ashish.kalra@xxxxxxx>
> CC: Tom Lendacky <thomas.lendacky@xxxxxxx>
> CC: John Allen <john.allen@xxxxxxx>
> CC: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
> CC: "David S. Miller" <davem@xxxxxxxxxxxxx>
> CC: Michael Roth <michael.roth@xxxxxxx>
> CC: Luis Chamberlain <mcgrof@xxxxxxxxxx>
> CC: Russ Weight <russ.weight@xxxxxxxxx>
> CC: Danilo Krummrich <dakr@xxxxxxxxxx>
> CC: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
> CC: "Rafael J. Wysocki" <rafael@xxxxxxxxxx>
> CC: Tianfei zhang <tianfei.zhang@xxxxxxxxx>
> CC: Alexey Kardashevskiy <aik@xxxxxxx>
> 
> Signed-off-by: Dionna Glaze <dionnaglaze@xxxxxxxxxx>

Reviewed-by: Tom Lendacky <thomas.lendacky@xxxxxxx>

> ---
>  arch/x86/kvm/svm/sev.c | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
> index 714c517dd4b72..f6e96ec0a5caa 100644
> --- a/arch/x86/kvm/svm/sev.c
> +++ b/arch/x86/kvm/svm/sev.c
> @@ -2212,10 +2212,6 @@ static int snp_launch_start(struct kvm *kvm, struct kvm_sev_cmd *argp)
>  	if (sev->snp_context)
>  		return -EINVAL;
>  
> -	sev->snp_context = snp_context_create(kvm, argp);
> -	if (!sev->snp_context)
> -		return -ENOTTY;
> -
>  	if (params.flags)
>  		return -EINVAL;
>  
> @@ -2230,6 +2226,10 @@ static int snp_launch_start(struct kvm *kvm, struct kvm_sev_cmd *argp)
>  	if (params.policy & SNP_POLICY_MASK_SINGLE_SOCKET)
>  		return -EINVAL;
>  
> +	sev->snp_context = snp_context_create(kvm, argp);
> +	if (!sev->snp_context)
> +		return -ENOTTY;
> +
>  	start.gctx_paddr = __psp_pa(sev->snp_context);
>  	start.policy = params.policy;
>  	memcpy(start.gosvw, params.gosvw, sizeof(params.gosvw));