From: Christian Borntraeger Date: Wed, 6 Aug 2014 14:17:58 +0000 (+0200) Subject: KVM: s390: Fix user triggerable bug in dead code X-Git-Tag: v3.2.64~99 X-Git-Url: https://git.openpandora.org/cgi-bin/gitweb.cgi?p=pandora-kernel.git;a=commitdiff_plain;h=30952365eec776b5251377f6ec343db0d26a6a1a;ds=sidebyside KVM: s390: Fix user triggerable bug in dead code commit 614a80e474b227cace52fd6e3c790554db8a396e upstream. In the early days, we had some special handling for the KVM_EXIT_S390_SIEIC exit, but this was gone in 2009 with commit d7b0b5eb3000 (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: Christian Borntraeger Reviewed-by: Cornelia Huck Reviewed-by: David Hildenbrand Signed-off-by: Ben Hutchings --- diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c index dd072b1add06..f6f41ddf7015 100644 --- a/arch/s390/kvm/kvm-s390.c +++ b/arch/s390/kvm/kvm-s390.c @@ -516,16 +516,6 @@ rerun_vcpu: BUG_ON(vcpu->kvm->arch.float_int.local_int[vcpu->vcpu_id] == NULL); - switch (kvm_run->exit_reason) { - case KVM_EXIT_S390_SIEIC: - case KVM_EXIT_UNKNOWN: - case KVM_EXIT_INTR: - case KVM_EXIT_S390_RESET: - break; - default: - BUG(); - } - vcpu->arch.sie_block->gpsw.mask = kvm_run->psw_mask; vcpu->arch.sie_block->gpsw.addr = kvm_run->psw_addr;