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Fri, 29 May 2026 11:36:08 -0700 (PDT) X-Received: by 2002:a05:600c:8b53:b0:490:5380:f2cb with SMTP id 5b1f17b1804b1-490a28d390emr15118485e9.0.1780079767918; Fri, 29 May 2026 11:36:07 -0700 (PDT) Received: from [192.168.10.48] ([151.49.251.208]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-4909c967c6csm64118605e9.2.2026.05.29.11.36.05 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 29 May 2026 11:36:06 -0700 (PDT) From: Paolo Bonzini To: linux-kernel@vger.kernel.org, kvm@vger.kernel.org Cc: seanjc@google.com, Tom Lendacky , Michael Roth , stable@vger.kernel.org Subject: [PATCH 07/24] KVM: SEV: WARN if KVM attempts to setup scratch area with min_len==0 Date: Fri, 29 May 2026 20:35:32 +0200 Message-ID: <20260529183549.1104619-8-pbonzini@redhat.com> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260529183549.1104619-1-pbonzini@redhat.com> References: <20260529183549.1104619-1-pbonzini@redhat.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Sean Christopherson Now that all paths in KVM properly validate the length needed for the scratch area, and are guaranteed to pass in a non-zero length, WARN if KVM attempts to configured the scratch area with min_len==0 to guard against future bugs. Cc: stable@vger.kernel.org Reviewed-by: Tom Lendacky Reviewed-by: Michael Roth Signed-off-by: Sean Christopherson Message-ID: <20260501202250.2115252-8-seanjc@google.com> Signed-off-by: Paolo Bonzini --- arch/x86/kvm/svm/sev.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c index 6072fecfe994..a3e85348ace9 100644 --- a/arch/x86/kvm/svm/sev.c +++ b/arch/x86/kvm/svm/sev.c @@ -3669,6 +3669,9 @@ static int setup_vmgexit_scratch(struct vcpu_svm *svm, bool sync, u64 min_len) u64 scratch_gpa_beg, scratch_gpa_end; void *scratch_va; + if (WARN_ON_ONCE(!min_len)) + goto e_scratch; + scratch_gpa_beg = svm->sev_es.sw_scratch; if (!scratch_gpa_beg) { pr_err("vmgexit: scratch gpa not provided\n"); -- 2.54.0