| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.19 48/85] kvm: sev: Fail KVM_SEV_INIT if already initialized | Date | Mon, 18 Feb 2019 14:43:14 +0100 |
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4.19-stable review patch. If anyone has any objections, please let me know.
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[ 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 02ac8fa0cd6d..ee8f8d70b98a 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -6256,6 +6256,9 @@ 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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