Re: [PATCH 4.19.y 1/3] KVM: arm64: vgic-its: Add a data length check in vgic_its_save_*

-- Thanks, Oliver > --- > virt/kvm/arm/vgic/vgic-its.c | 20 ++++++++------------ > virt/kvm/arm/vgic/vgic.h | 24 ++++++++++++++++++++++++ > 2 files changed, 32 insertions(+), 12 deletions(-) > > diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c > index 2fb26bd3106e..7fcf903fa5b0 100644 > --- a/virt/kvm/arm/vgic/vgic-its.c > +++ b/virt/kvm/arm/vgic/vgic-its.c > @@ -1949,7 +1949,6 @@ static int scan_its_table(struct vgic_its *its, gpa_t base, int size, u32 esz, > static int vgic_its_save_ite(struct vgic_its *its, struct its_device *dev, > struct its_ite *ite, gpa_t gpa, int ite_esz) > { > - struct kvm *kvm = its->dev->kvm; > u32 next_offset; > u64 val; > > @@ -1958,7 +1957,8 @@ static int vgic_its_save_ite(struct vgic_its *its, struct its_device *dev, > ((u64)ite->irq->intid << KVM_ITS_ITE_PINTID_SHIFT) | > ite->collection->collection_id; > val = cpu_to_le64(val); > - return kvm_write_guest_lock(kvm, gpa, &val, ite_esz); > + > + return vgic_its_write_entry_lock(its, gpa, val, ite_esz); > } > > /** > @@ -2094,7 +2094,6 @@ static int vgic_its_restore_itt(struct vgic_its *its, struct its_device *dev) > static int vgic_its_save_dte(struct vgic_its *its, struct its_device *dev, > gpa_t ptr, int dte_esz) > { > - struct kvm *kvm = its->dev->kvm; > u64 val, itt_addr_field; > u32 next_offset; > > @@ -2105,7 +2104,8 @@ static int vgic_its_save_dte(struct vgic_its *its, struct its_device *dev, > (itt_addr_field << KVM_ITS_DTE_ITTADDR_SHIFT) | > (dev->num_eventid_bits - 1)); > val = cpu_to_le64(val); > - return kvm_write_guest_lock(kvm, ptr, &val, dte_esz); > + > + return vgic_its_write_entry_lock(its, ptr, val, dte_esz); > } > > /** > @@ -2285,7 +2285,8 @@ static int vgic_its_save_cte(struct vgic_its *its, > ((u64)collection->target_addr << KVM_ITS_CTE_RDBASE_SHIFT) | > collection->collection_id); > val = cpu_to_le64(val); > - return kvm_write_guest_lock(its->dev->kvm, gpa, &val, esz); > + > + return vgic_its_write_entry_lock(its, gpa, val, esz); > } > > static int vgic_its_restore_cte(struct vgic_its *its, gpa_t gpa, int esz) > @@ -2296,8 +2297,7 @@ static int vgic_its_restore_cte(struct vgic_its *its, gpa_t gpa, int esz) > u64 val; > int ret; > > - BUG_ON(esz > sizeof(val)); > - ret = kvm_read_guest_lock(kvm, gpa, &val, esz); > + ret = vgic_its_read_entry_lock(its, gpa, &val, esz); > if (ret) > return ret; > val = le64_to_cpu(val); > @@ -2331,7 +2331,6 @@ static int vgic_its_save_collection_table(struct vgic_its *its) > u64 baser = its->baser_coll_table; > gpa_t gpa = BASER_ADDRESS(baser); > struct its_collection *collection; > - u64 val; > size_t max_size, filled = 0; > int ret, cte_esz = abi->cte_esz; > > @@ -2355,10 +2354,7 @@ static int vgic_its_save_collection_table(struct vgic_its *its) > * table is not fully filled, add a last dummy element > * with valid bit unset > */ > - val = 0; > - BUG_ON(cte_esz > sizeof(val)); > - ret = kvm_write_guest_lock(its->dev->kvm, gpa, &val, cte_esz); > - return ret; > + return vgic_its_write_entry_lock(its, gpa, 0, cte_esz); > } > > /** > diff --git a/virt/kvm/arm/vgic/vgic.h b/virt/kvm/arm/vgic/vgic.h > index d5e454279925..e5a307dab61e 100644 > --- a/virt/kvm/arm/vgic/vgic.h > +++ b/virt/kvm/arm/vgic/vgic.h > @@ -17,6 +17,7 @@ > #define __KVM_ARM_VGIC_NEW_H__ > > #include <linux/irqchip/arm-gic-common.h> > +#include <asm/kvm_mmu.h> > > #define PRODUCT_ID_KVM 0x4b /* ASCII code K */ > #define IMPLEMENTER_ARM 0x43b > @@ -137,6 +138,29 @@ static inline bool vgic_irq_is_multi_sgi(struct vgic_irq *irq) > return vgic_irq_get_lr_count(irq) > 1; > } > > +static inline int vgic_its_read_entry_lock(struct vgic_its *its, gpa_t eaddr, > + u64 *eval, unsigned long esize) > +{ > + struct kvm *kvm = its->dev->kvm; > + > + if (KVM_BUG_ON(esize != sizeof(*eval), kvm)) > + return -EINVAL; > + > + return kvm_read_guest_lock(kvm, eaddr, eval, esize); > + > +} > + > +static inline int vgic_its_write_entry_lock(struct vgic_its *its, gpa_t eaddr, > + u64 eval, unsigned long esize) > +{ > + struct kvm *kvm = its->dev->kvm; > + > + if (KVM_BUG_ON(esize != sizeof(eval), kvm)) > + return -EINVAL; > + > + return kvm_write_guest_lock(kvm, eaddr, &eval, esize); > +} > + > /* > * This struct provides an intermediate representation of the fields contained > * in the GICH_VMCR and ICH_VMCR registers, such that code exporting the GIC > > base-commit: 708f578f2a8f702d2f2a0ef5e6eac28e08206e03 > -- > 2.47.0.338.g60cca15819-goog >