KVM: s390: Disallow invalid bits in kvm_valid_regs and kvm_dirty_regs (200824f5) · Commits · 戴 / test

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>

arch/s390/include/uapi/asm/kvm.h

+6 −0

Original line number	Diff line number	Diff line
		@@ -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)

arch/s390/kvm/kvm-s390.c

+4 −0

Original line number	Diff line number	Diff line
		@@ -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)) {

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