Re: [PATCHv2] kvm-s390: fix potential array overrun in intercept handling

[Christian Borntraeger <borntraeger@de.ibm.com>]

Am Donnerstag 21 Januar 2010 12:24:18 schrieb Heiko Carstens:
> > -	if (code & 3 || code > 0x48)
> > +	if (code & 3 || (code >> 2)  >= ARRAY_SIZE(intercept_funcs))
> >  		return -ENOTSUPP;
> 
> Not that it matters for this patch, but -ENOTSUPP should not leak to
> userspace. Not sure if it does somewhere, but it is used all over the
> place within arch/s390/kvm...
> Use -EOPNOTSUPP or something similar instead.

AFAICS it does not leak to userspace, ENOTSUPP is an internal code. see
kvm_arch_vcpu_ioctl_run:
[...]
        if (rc == -ENOTSUPP) {
                /* intercept cannot be handled in-kernel, prepare kvm-run */
                kvm_run->exit_reason         = KVM_EXIT_S390_SIEIC;
                kvm_run->s390_sieic.icptcode = vcpu->arch.sie_block->icptcode;
                kvm_run->s390_sieic.ipa      = vcpu->arch.sie_block->ipa;
                kvm_run->s390_sieic.ipb      = vcpu->arch.sie_block->ipb;
                rc = 0;
        }
[...]