From: Thomas Huth <thuth@redhat.com>
Date: Wed, 4 Sep 2019 10:51:59 +0200
Subject: KVM: s390: Disallow invalid bits in kvm_valid_regs and kvm_dirty_regs
Git-commit: 200824f55eef409830a2d1703d6f81542620c2f0
Patch-mainline: v5.4-rc1
References: jsc#SLE-7512 bsc#1165545
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>
Acked-by: Petr Tesarik <ptesarik@suse.com>
---
arch/s390/include/uapi/asm/kvm.h | 6 ++++++
arch/s390/kvm/kvm-s390.c | 4 ++++
2 files changed, 10 insertions(+)
--- 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)
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -4000,6 +4000,10 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_v
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)) {