From: Mingwei Zhang Date: Sun, 12 Sep 2021 18:18:15 +0000 (+0000) Subject: KVM: SVM: fix missing sev_decommission in sev_receive_start X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=f1815e0aa770f2127c5df31eb5c2f0e37b60fa77;p=linux.git KVM: SVM: fix missing sev_decommission in sev_receive_start DECOMMISSION the current SEV context if binding an ASID fails after RECEIVE_START. Per AMD's SEV API, RECEIVE_START generates a new guest context and thus needs to be paired with DECOMMISSION: The RECEIVE_START command is the only command other than the LAUNCH_START command that generates a new guest context and guest handle. The missing DECOMMISSION can result in subsequent SEV launch failures, as the firmware leaks memory and might not able to allocate more SEV guest contexts in the future. Note, LAUNCH_START suffered the same bug, but was previously fixed by commit 934002cd660b ("KVM: SVM: Call SEV Guest Decommission if ASID binding fails"). Cc: Alper Gun Cc: Borislav Petkov Cc: Brijesh Singh Cc: David Rienjes Cc: Marc Orr Cc: John Allen Cc: Peter Gonda Cc: Sean Christopherson Cc: Tom Lendacky Cc: Vipin Sharma Cc: stable@vger.kernel.org Reviewed-by: Marc Orr Acked-by: Brijesh Singh Fixes: af43cbbf954b ("KVM: SVM: Add support for KVM_SEV_RECEIVE_START command") Signed-off-by: Mingwei Zhang Reviewed-by: Sean Christopherson Message-Id: <20210912181815.3899316-1-mizhang@google.com> Signed-off-by: Paolo Bonzini --- diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c index 61c4bf4b3a0a8..4d68a37a8a24e 100644 --- a/arch/x86/kvm/svm/sev.c +++ b/arch/x86/kvm/svm/sev.c @@ -1404,8 +1404,10 @@ static int sev_receive_start(struct kvm *kvm, struct kvm_sev_cmd *argp) /* Bind ASID to this guest */ ret = sev_bind_asid(kvm, start.handle, error); - if (ret) + if (ret) { + sev_decommission(start.handle); goto e_free_session; + } params.handle = start.handle; if (copy_to_user((void __user *)(uintptr_t)argp->data,