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Commit 614a80e4 authored by Christian Borntraeger's avatar Christian Borntraeger
Browse files

KVM: s390: Fix user triggerable bug in dead code 



In the early days, we had some special handling for the
KVM_EXIT_S390_SIEIC exit, but this was gone in 2009 with commit
d7b0b5eb (KVM: s390: Make psw available on all exits, not
just a subset).

Now this switch statement is just a sanity check for userspace
not messing with the kvm_run structure. Unfortunately, this
allows userspace to trigger a kernel BUG. Let's just remove
this switch statement.

Signed-off-by: default avatarChristian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: default avatarCornelia Huck <cornelia.huck@de.ibm.com>
Reviewed-by: default avatarDavid Hildenbrand <dahi@linux.vnet.ibm.com>
Cc: stable@vger.kernel.org
parent 7d1311b9

arch/s390/kvm/kvm-s390.c

+0 −13
Original line number Diff line number Diff line
@@ -1317,19 +1317,6 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run) 
		return -EINVAL;

	}



	switch (kvm_run->exit_reason) {

	case KVM_EXIT_S390_SIEIC:

	case KVM_EXIT_UNKNOWN:

	case KVM_EXIT_INTR:

	case KVM_EXIT_S390_RESET:

	case KVM_EXIT_S390_UCONTROL:

	case KVM_EXIT_S390_TSCH:

	case KVM_EXIT_DEBUG:

		break;

	default:

		BUG();

	}



	vcpu->arch.sie_block->gpsw.mask = kvm_run->psw_mask;

	vcpu->arch.sie_block->gpsw.addr = kvm_run->psw_addr;

	if (kvm_run->kvm_dirty_regs & KVM_SYNC_PREFIX) {