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authorThomas Huth <thuth@redhat.com>2019-09-04 11:51:59 +0300
committerJanosch Frank <frankja@linux.ibm.com>2019-09-04 16:38:05 +0300
commit200824f55eef409830a2d1703d6f81542620c2f0 (patch)
treeb996508dee9c50a0ac149f4eb354a0939559ff38
parentbe6f55a60d28fb31864d3aab011cf4e1fc0dba04 (diff)
downloadlinux-200824f55eef409830a2d1703d6f81542620c2f0.tar.xz
KVM: s390: Disallow invalid bits in kvm_valid_regs and kvm_dirty_regs
If unknown bits are set in kvm_valid_regs or kvm_dirty_regs, this clearly indicates that something went wrong in the KVM userspace application. The x86 variant of KVM already contains a check for bad bits, so let's do the same on s390x now, too. Reviewed-by: Janosch Frank <frankja@linux.ibm.com> Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Reviewed-by: David Hildenbrand <david@redhat.com> Signed-off-by: Thomas Huth <thuth@redhat.com> Link: https://lore.kernel.org/lkml/20190904085200.29021-2-thuth@redhat.com/ Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
-rw-r--r--arch/s390/include/uapi/asm/kvm.h6
-rw-r--r--arch/s390/kvm/kvm-s390.c4
2 files changed, 10 insertions, 0 deletions
diff --git a/arch/s390/include/uapi/asm/kvm.h b/arch/s390/include/uapi/asm/kvm.h
index 47104e5b47fd..436ec7636927 100644
--- a/arch/s390/include/uapi/asm/kvm.h
+++ b/arch/s390/include/uapi/asm/kvm.h
@@ -231,6 +231,12 @@ struct kvm_guest_debug_arch {
#define KVM_SYNC_GSCB (1UL << 9)
#define KVM_SYNC_BPBC (1UL << 10)
#define KVM_SYNC_ETOKEN (1UL << 11)
+
+#define KVM_SYNC_S390_VALID_FIELDS \
+ (KVM_SYNC_PREFIX | KVM_SYNC_GPRS | KVM_SYNC_ACRS | KVM_SYNC_CRS | \
+ KVM_SYNC_ARCH0 | KVM_SYNC_PFAULT | KVM_SYNC_VRS | KVM_SYNC_RICCB | \
+ KVM_SYNC_FPRS | KVM_SYNC_GSCB | KVM_SYNC_BPBC | KVM_SYNC_ETOKEN)
+
/* length and alignment of the sdnx as a power of two */
#define SDNXC 8
#define SDNXL (1UL << SDNXC)
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index d41c091546b7..a3d4527ac23b 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -4008,6 +4008,10 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
if (kvm_run->immediate_exit)
return -EINTR;
+ if (kvm_run->kvm_valid_regs & ~KVM_SYNC_S390_VALID_FIELDS ||
+ kvm_run->kvm_dirty_regs & ~KVM_SYNC_S390_VALID_FIELDS)
+ return -EINVAL;
+
vcpu_load(vcpu);
if (guestdbg_exit_pending(vcpu)) {