From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 005313DB96F; Tue, 12 May 2026 17:42:33 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778607754; cv=none; b=RobK9d0zjbFikrDk58vDD0v8Rd1Jve0tiNPIlz2TPlZoHuDD1EMNN+2PjplA2Xyt+UVyKo1Pc9EjrDJ8JWikZ52WA7G4E/uJuunkQyynZyQS/qOxosdEKQj1hua0hi0OabeRVOIBiqb0p3JqsoceCsvYmYMPw8X0rXbfDYMoGzA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778607754; c=relaxed/simple; bh=Zwjb6lLpMjXOijZJNUjbQl3u9slG8S2JAmWK8eHZOk4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=kf+baVGI+kF6LAZmhVVb9yCqLckf6goTNv0xjAsy3T+2f0d7CHiaE3LnwcZbxyxsytU5KmBtwNrv8YoZT3nNfCK9O8Hu9OSCAt7Wk54aEx+qA8RK30JU/JkGsVtJ/MgWawJQsouyyEVbg4X/1cQ9h7zz1B+okHM9ODO2zxAPVOA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=j7jhAEXn; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="j7jhAEXn" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 46062C2BCB0; Tue, 12 May 2026 17:42:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1778607753; bh=Zwjb6lLpMjXOijZJNUjbQl3u9slG8S2JAmWK8eHZOk4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=j7jhAEXnuLlcToH02pWuhwfXoEDQy//Nvmt4qFTSaEHh32PNYyjypTo0Q1o9Bgotu cLdPmULlHM2SGn1Txw4gHlHQQbMvidxERxADr0xSbW5jV7H9bTW70mors/6AHrT7DT xGRTZXwgD8pS9W2SiaHdLgL+7VEaXJOThLnsvlBY= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Paolo Bonzini Subject: [PATCH 6.12 023/206] KVM: SVM: check validity of VMCB controls when returning from SMM Date: Tue, 12 May 2026 19:37:55 +0200 Message-ID: <20260512173933.316221862@linuxfoundation.org> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260512173932.810559588@linuxfoundation.org> References: <20260512173932.810559588@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Paolo Bonzini commit be5fa8737d42c5ba16d2ea72c23681f8abbb07e8 upstream. The VMCB12 is stored in guest memory and can be mangled while in SMM; it is then reloaded by svm_leave_smm(), but it is not checked again for validity. Move the cached vmcb12 control and save consistency checks out of svm_set_nested_state() and into a helper, and reuse it in svm_leave_smm(). Signed-off-by: Paolo Bonzini Signed-off-by: Greg Kroah-Hartman --- arch/x86/kvm/svm/nested.c | 12 ++++++++++-- arch/x86/kvm/svm/svm.c | 4 ++++ arch/x86/kvm/svm/svm.h | 1 + 3 files changed, 15 insertions(+), 2 deletions(-) --- a/arch/x86/kvm/svm/nested.c +++ b/arch/x86/kvm/svm/nested.c @@ -416,6 +416,15 @@ void nested_copy_vmcb_save_to_cache(stru __nested_copy_vmcb_save_to_cache(&svm->nested.save, save); } +int nested_svm_check_cached_vmcb12(struct kvm_vcpu *vcpu) +{ + if (!nested_vmcb_check_save(vcpu) || + !nested_vmcb_check_controls(vcpu)) + return -EINVAL; + + return 0; +} + /* * Synchronize fields that are written by the processor, so that * they can be copied back into the vmcb12. @@ -883,8 +892,7 @@ int nested_svm_vmrun(struct kvm_vcpu *vc nested_copy_vmcb_control_to_cache(svm, &vmcb12->control); nested_copy_vmcb_save_to_cache(svm, &vmcb12->save); - if (!nested_vmcb_check_save(vcpu) || - !nested_vmcb_check_controls(vcpu)) { + if (nested_svm_check_cached_vmcb12(vcpu) < 0) { vmcb12->control.exit_code = SVM_EXIT_ERR; vmcb12->control.exit_code_hi = -1u; vmcb12->control.exit_info_1 = 0; --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -4934,6 +4934,10 @@ static int svm_leave_smm(struct kvm_vcpu vmcb12 = map.hva; nested_copy_vmcb_control_to_cache(svm, &vmcb12->control); nested_copy_vmcb_save_to_cache(svm, &vmcb12->save); + + if (nested_svm_check_cached_vmcb12(vcpu) < 0) + goto unmap_save; + ret = enter_svm_guest_mode(vcpu, smram64->svm_guest_vmcb_gpa, vmcb12, false); if (ret) --- a/arch/x86/kvm/svm/svm.h +++ b/arch/x86/kvm/svm/svm.h @@ -672,6 +672,7 @@ static inline int nested_svm_simple_vmex int nested_svm_exit_handled(struct vcpu_svm *svm); int nested_svm_check_permissions(struct kvm_vcpu *vcpu); +int nested_svm_check_cached_vmcb12(struct kvm_vcpu *vcpu); int nested_svm_check_exception(struct vcpu_svm *svm, unsigned nr, bool has_error_code, u32 error_code); int nested_svm_exit_special(struct vcpu_svm *svm);