From patchwork Fri Jun 3 17:43:29 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 12869294 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A431AC433EF for ; Fri, 3 Jun 2022 18:07:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232917AbiFCSHo (ORCPT ); Fri, 3 Jun 2022 14:07:44 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46466 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1346320AbiFCSEz (ORCPT ); Fri, 3 Jun 2022 14:04:55 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 00E135712F; Fri, 3 Jun 2022 10:58:02 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 366A5B82189; Fri, 3 Jun 2022 17:57:06 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 96FB2C385B8; Fri, 3 Jun 2022 17:57:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1654279025; bh=wTV5cVFc5rKLzg7MqcEFuVDlN6PsOXkUdWpdiX9W7qI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=XLDvkMc/Bq4S5SvdIZCQ4GpGJxuUhdFFKrMHdTxTokL/G9HZ3MYKRK1sJgtt60Hga qMJbc6vmDaov765QYnsRTe9GuHHCMkffsGFlDxaBte99WHRXu9oPUiOb+44u9MaiUM gZUT/veLR3/hG1A/vChceoU2IRHPbeyU4ugirBtM= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Andy Nguyen , David Rientjes , Peter Gonda , kvm@vger.kernel.org, Ashish Kalra , Paolo Bonzini Subject: [PATCH 5.18 28/67] KVM: SVM: Use kzalloc for sev ioctl interfaces to prevent kernel data leak Date: Fri, 3 Jun 2022 19:43:29 +0200 Message-Id: <20220603173821.535586563@linuxfoundation.org> X-Mailer: git-send-email 2.36.1 In-Reply-To: <20220603173820.731531504@linuxfoundation.org> References: <20220603173820.731531504@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org From: Ashish Kalra commit d22d2474e3953996f03528b84b7f52cc26a39403 upstream. For some sev ioctl interfaces, the length parameter that is passed maybe less than or equal to SEV_FW_BLOB_MAX_SIZE, but larger than the data that PSP firmware returns. In this case, kmalloc will allocate memory that is the size of the input rather than the size of the data. Since PSP firmware doesn't fully overwrite the allocated buffer, these sev ioctl interface may return uninitialized kernel slab memory. Reported-by: Andy Nguyen Suggested-by: David Rientjes Suggested-by: Peter Gonda Cc: kvm@vger.kernel.org Cc: stable@vger.kernel.org Cc: linux-kernel@vger.kernel.org Fixes: eaf78265a4ab3 ("KVM: SVM: Move SEV code to separate file") Fixes: 2c07ded06427d ("KVM: SVM: add support for SEV attestation command") Fixes: 4cfdd47d6d95a ("KVM: SVM: Add KVM_SEV SEND_START command") Fixes: d3d1af85e2c75 ("KVM: SVM: Add KVM_SEND_UPDATE_DATA command") Fixes: eba04b20e4861 ("KVM: x86: Account a variety of miscellaneous allocations") Signed-off-by: Ashish Kalra Reviewed-by: Peter Gonda Message-Id: <20220516154310.3685678-1-Ashish.Kalra@amd.com> Signed-off-by: Paolo Bonzini Signed-off-by: Greg Kroah-Hartman --- arch/x86/kvm/svm/sev.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) --- a/arch/x86/kvm/svm/sev.c +++ b/arch/x86/kvm/svm/sev.c @@ -688,7 +688,7 @@ static int sev_launch_measure(struct kvm if (params.len > SEV_FW_BLOB_MAX_SIZE) return -EINVAL; - blob = kmalloc(params.len, GFP_KERNEL_ACCOUNT); + blob = kzalloc(params.len, GFP_KERNEL_ACCOUNT); if (!blob) return -ENOMEM; @@ -808,7 +808,7 @@ static int __sev_dbg_decrypt_user(struct if (!IS_ALIGNED(dst_paddr, 16) || !IS_ALIGNED(paddr, 16) || !IS_ALIGNED(size, 16)) { - tpage = (void *)alloc_page(GFP_KERNEL); + tpage = (void *)alloc_page(GFP_KERNEL | __GFP_ZERO); if (!tpage) return -ENOMEM; @@ -1094,7 +1094,7 @@ static int sev_get_attestation_report(st if (params.len > SEV_FW_BLOB_MAX_SIZE) return -EINVAL; - blob = kmalloc(params.len, GFP_KERNEL_ACCOUNT); + blob = kzalloc(params.len, GFP_KERNEL_ACCOUNT); if (!blob) return -ENOMEM; @@ -1176,7 +1176,7 @@ static int sev_send_start(struct kvm *kv return -EINVAL; /* allocate the memory to hold the session data blob */ - session_data = kmalloc(params.session_len, GFP_KERNEL_ACCOUNT); + session_data = kzalloc(params.session_len, GFP_KERNEL_ACCOUNT); if (!session_data) return -ENOMEM; @@ -1300,11 +1300,11 @@ static int sev_send_update_data(struct k /* allocate memory for header and transport buffer */ ret = -ENOMEM; - hdr = kmalloc(params.hdr_len, GFP_KERNEL_ACCOUNT); + hdr = kzalloc(params.hdr_len, GFP_KERNEL_ACCOUNT); if (!hdr) goto e_unpin; - trans_data = kmalloc(params.trans_len, GFP_KERNEL_ACCOUNT); + trans_data = kzalloc(params.trans_len, GFP_KERNEL_ACCOUNT); if (!trans_data) goto e_free_hdr;