| Message ID | 20180514100029.32910-4-aik@ozlabs.ru |
|---|---|
| State | Accepted |
| Headers | show |
| Series | KVM: PPC: Allow backing bigger guest IOMMU pages with smaller physical | expand |
On Mon, May 14, 2018 at 8:00 PM, Alexey Kardashevskiy <aik@ozlabs.ru> wrote: > Although it does not seem possible to break the host by passing bad > parameters when creating a TCE table in KVM, it is still better to get > an early clear indication of that than debugging weird effect this might > bring. > > This adds some sanity checks that the page size is 4KB..16GB as this is > what the actual LoPAPR supports and that the window actually fits 64bit > space. > > Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> > --- > arch/powerpc/kvm/book3s_64_vio.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/arch/powerpc/kvm/book3s_64_vio.c b/arch/powerpc/kvm/book3s_64_vio.c > index 984f197..80ead38 100644 > --- a/arch/powerpc/kvm/book3s_64_vio.c > +++ b/arch/powerpc/kvm/book3s_64_vio.c > @@ -300,7 +300,8 @@ long kvm_vm_ioctl_create_spapr_tce(struct kvm *kvm, > int ret = -ENOMEM; > int i; > > - if (!args->size) > + if (!args->size || args->page_shift < 12 || args->page_shift > 34 || > + (args->offset + args->size > (ULLONG_MAX >> args->page_shift))) Acked-by: Balbir Singh <bsingharora@gmail.com> Balbir -- To unsubscribe from this list: send the line "unsubscribe kvm-ppc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Mon, May 14, 2018 at 08:00:29PM +1000, Alexey Kardashevskiy wrote: > Although it does not seem possible to break the host by passing bad > parameters when creating a TCE table in KVM, it is still better to get > an early clear indication of that than debugging weird effect this might > bring. > > This adds some sanity checks that the page size is 4KB..16GB as this is > what the actual LoPAPR supports and that the window actually fits 64bit > space. > > Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> > --- > arch/powerpc/kvm/book3s_64_vio.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/arch/powerpc/kvm/book3s_64_vio.c b/arch/powerpc/kvm/book3s_64_vio.c > index 984f197..80ead38 100644 > --- a/arch/powerpc/kvm/book3s_64_vio.c > +++ b/arch/powerpc/kvm/book3s_64_vio.c > @@ -300,7 +300,8 @@ long kvm_vm_ioctl_create_spapr_tce(struct kvm *kvm, > int ret = -ENOMEM; > int i; > > - if (!args->size) > + if (!args->size || args->page_shift < 12 || args->page_shift > 34 || > + (args->offset + args->size > (ULLONG_MAX >> args->page_shift))) > return -EINVAL; > > size = _ALIGN_UP(args->size, PAGE_SIZE >> 3);
diff --git a/arch/powerpc/kvm/book3s_64_vio.c b/arch/powerpc/kvm/book3s_64_vio.c index 984f197..80ead38 100644 --- a/arch/powerpc/kvm/book3s_64_vio.c +++ b/arch/powerpc/kvm/book3s_64_vio.c @@ -300,7 +300,8 @@ long kvm_vm_ioctl_create_spapr_tce(struct kvm *kvm, int ret = -ENOMEM; int i; - if (!args->size) + if (!args->size || args->page_shift < 12 || args->page_shift > 34 || + (args->offset + args->size > (ULLONG_MAX >> args->page_shift))) return -EINVAL; size = _ALIGN_UP(args->size, PAGE_SIZE >> 3);
Although it does not seem possible to break the host by passing bad parameters when creating a TCE table in KVM, it is still better to get an early clear indication of that than debugging weird effect this might bring. This adds some sanity checks that the page size is 4KB..16GB as this is what the actual LoPAPR supports and that the window actually fits 64bit space. Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> --- arch/powerpc/kvm/book3s_64_vio.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)