Messages in this thread Patch in this message | | | From | Sasha Levin <> | Subject | [PATCH AUTOSEL 4.19 28/28] kvm: sev: Fail KVM_SEV_INIT if already initialized | Date | Sat, 9 Feb 2019 13:48:36 -0500 |
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From: David Rientjes <rientjes@google.com>
[ Upstream commit 3f14a89d1132dcae3c8ce6721c6ef51f6e6d9b5f ]
By code inspection, it was found that multiple calls to KVM_SEV_INIT could deplete asid bits and overwrite kvm_sev_info's regions_list.
Multiple calls to KVM_SVM_INIT is not likely to occur with QEMU, but this should likely be fixed anyway.
This code is serialized by kvm->lock.
Fixes: 1654efcbc431 ("KVM: SVM: Add KVM_SEV_INIT command") Reported-by: Cfir Cohen <cfir@google.com> Signed-off-by: David Rientjes <rientjes@google.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org> --- arch/x86/kvm/svm.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index f1d3fe5a0c65..0976853ed723 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -6249,6 +6249,9 @@ static int sev_guest_init(struct kvm *kvm, struct kvm_sev_cmd *argp) int asid, ret; ret = -EBUSY; + if (unlikely(sev->active)) + return ret; + asid = sev_asid_new(); if (asid < 0) return ret; -- 2.19.1
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