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authorRadim Krčmář <rkrcmar@redhat.com>2016-10-20 20:31:01 +0200
committerRadim Krčmář <rkrcmar@redhat.com>2016-10-20 20:31:01 +0200
commit3633031db5bcc87f5b7d9938c4f94bc8f178c51f (patch)
treec810ccaa1a0dfbf757fa58d243b649906ee8c679
parentf6bbf1b7ac1fba284df82d7344080a8e7435b023 (diff)
parenta5efb6b6c99a3a6dc4330f51d8066f638bdea0ac (diff)
downloadlinux-stericsson-3633031db5bcc87f5b7d9938c4f94bc8f178c51f.tar.gz
Merge tag 'kvm-s390-master-4.9-1' of git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux
KVM: s390: Fix for user-triggerable WARN_ON A malicious user space can provide an invalid mode for runtime instrumentation via the interfaces that are normally used on the target host during migration. This would trigger a WARN_ON via validity intercept. Let's detect this special case.
-rw-r--r--arch/s390/kvm/intercept.c9
1 files changed, 7 insertions, 2 deletions
diff --git a/arch/s390/kvm/intercept.c b/arch/s390/kvm/intercept.c
index 1cab8a177d0e..7a27eebab28a 100644
--- a/arch/s390/kvm/intercept.c
+++ b/arch/s390/kvm/intercept.c
@@ -119,8 +119,13 @@ static int handle_validity(struct kvm_vcpu *vcpu)
vcpu->stat.exit_validity++;
trace_kvm_s390_intercept_validity(vcpu, viwhy);
- WARN_ONCE(true, "kvm: unhandled validity intercept 0x%x\n", viwhy);
- return -EOPNOTSUPP;
+ KVM_EVENT(3, "validity intercept 0x%x for pid %u (kvm 0x%pK)", viwhy,
+ current->pid, vcpu->kvm);
+
+ /* do not warn on invalid runtime instrumentation mode */
+ WARN_ONCE(viwhy != 0x44, "kvm: unhandled validity intercept 0x%x\n",
+ viwhy);
+ return -EINVAL;
}
static int handle_instruction(struct kvm_vcpu *vcpu)