From mboxrd@z Thu Jan 1 00:00:00 1970 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 398F3C5479D for ; Wed, 11 Jan 2023 19:40:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235127AbjAKTky (ORCPT ); Wed, 11 Jan 2023 14:40:54 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44550 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234200AbjAKTkK (ORCPT ); Wed, 11 Jan 2023 14:40:10 -0500 Received: from mail-pf1-x44a.google.com (mail-pf1-x44a.google.com [IPv6:2607:f8b0:4864:20::44a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5E24C39F96 for ; Wed, 11 Jan 2023 11:40:08 -0800 (PST) Received: by mail-pf1-x44a.google.com with SMTP id b196-20020a621bcd000000b0058a63dc105eso3482114pfb.6 for ; Wed, 11 Jan 2023 11:40:08 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=t8W4FH7mFIpVRdnY5skujk6nCPAJ4sesqHc9zDdEW0s=; b=IF6bG7y6P+/fyh2juFdCBqZAZykQrxC8/Vm0GE5HmM6OxW12uKLT/dtRZAWDhMxB+d dkiawoVtjIwhjo34pV/6UTuHh0u2ClKSRJnWy1XwXXBJcrHGAIp0OeWebvNjf+1+f+0i 7ILSBx7UCXoHIsBP2UMpqG3sBq7p/t/VdawaoUWPYzAnd0DJIeAS5kmj561hIyiu1Uob I5gM9i5f5bh+uesfHys7f9yRa6RlGAFF1A4PTwCEXb5xzpkV9vWbtWfCv9t6B1+drSBR WG3GNCUByYQBO6Jc9AQvYimY2JAtUvyfWo2IDqPU0bFEDaV78SJQD+g8FtStiP67tMvk Vx/g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=t8W4FH7mFIpVRdnY5skujk6nCPAJ4sesqHc9zDdEW0s=; b=IIO9DAjYYmZ9KcoqlWFwlWNWTTOaGZZEOMcxOp4TgKYCwKqwuT4EY1gRlu7Mgggr77 C2oszkHODLRZcL71+MrBp6py3nntPp/FxMo/xbVxwHCt9e0D+wK+bpyh0FV4zL7grjs3 6rOZJN+Ubp7CIsy0gMKGEoNM5Tfi0khDuZpGcu1yZCvijLnMhRclzZHN/1FsTKkU7qUu IRaF5nOLBlLGdGJvVVyWApYp8JchL6d2EpQur6EcGMdZCIiW0G0ewaP9w86rj5vDkwsZ /scuYwlHtEbUp5QZkm/zxA/gWIqzIowQbrwp76P38z0CNRb2+8vqxI170zkGuE6PYCfJ yDyg== X-Gm-Message-State: AFqh2krj+iul/5kte+2MXibgJAIkZJsConTF7n9WuxpfsStxQqVA2dUw 7hRjFRao+Abcrt9cefX/KGAgzWVkJ4I3tkJGll2WAAq3zgNr8IUuTOkdHnHXNLk37r3D6gt9s+L y0vK1H0LvcaETK7oY4TP+zwv/PRVtZn6LwFRIS32OPc0exsMXa6stwfYD0l53wlM6CaLixsE+Hk s02H5ytOk= X-Google-Smtp-Source: AMrXdXullgIk5Od9JoOE6RkbMRJw+bgqLxHKZ1NwCMe5CScZ7ktTdffp1urqcFQ6zinZNL53fnPSTQkPGlsBkNkRxg== X-Received: from dionnaglaze.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:2ee6]) (user=dionnaglaze job=sendgmr) by 2002:a17:902:7c02:b0:192:fb0a:35aa with SMTP id x2-20020a1709027c0200b00192fb0a35aamr1611751pll.78.1673466007663; Wed, 11 Jan 2023 11:40:07 -0800 (PST) Date: Wed, 11 Jan 2023 19:39:57 +0000 In-Reply-To: <20230111194001.1947849-1-dionnaglaze@google.com> Mime-Version: 1.0 References: <20230111194001.1947849-1-dionnaglaze@google.com> X-Mailer: git-send-email 2.39.0.314.g84b9a713c41-goog Message-ID: <20230111194001.1947849-4-dionnaglaze@google.com> Subject: [PATCH v11 3/7] virt: sev-guest: Remove err in handle_guest_request From: Dionna Glaze To: linux-kernel@vger.kernel.org, x86@kernel.org Cc: Dionna Glaze , Tom Lendacky , Paolo Bonzini , Joerg Roedel , Peter Gonda , Thomas Gleixner , Dave Hansen , Borislav Petkov , Haowen Bai , Liam Merwick , Yang Yingliang Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The err variable may not be set in the call to snp_issue_guest_request, yet it is unconditionally written back to fw_err if fw_err is non-null. This is undefined behavior, and currently returns uninitialized kernel stack memory to user space. The fw_err argument is better to just pass through to snp_issue_guest_request, so that's done by passing along the ioctl argument. This removes the need for an argument to handle_guest_request. Instead of using the fw_err field of the argument, which is a bit of a misnomer, instead change to exitinfo2. The exitinfo2 field type is a temporary typedef that will be removed. Cc: Tom Lendacky Cc: Paolo Bonzini Cc: Joerg Roedel Cc: Peter Gonda Cc: Thomas Gleixner Cc: Dave Hansen Cc: Borislav Petkov Cc: Haowen Bai Cc: Liam Merwick Cc: Yang Yingliang Fixes: fce96cf04430 ("virt: Add SEV-SNP guest driver") Reviewed-by: Tom Lendacky Reviewed-by: Borislav Petkov Reviewed-by: Peter Gonda Signed-off-by: Dionna Glaze --- drivers/virt/coco/sev-guest/sev-guest.c | 43 ++++++++++++------------- include/uapi/linux/sev-guest.h | 12 +++++-- 2 files changed, 31 insertions(+), 24 deletions(-) diff --git a/drivers/virt/coco/sev-guest/sev-guest.c b/drivers/virt/coco/sev-guest/sev-guest.c index 4ec4174e05a3..e2fcb5215630 100644 --- a/drivers/virt/coco/sev-guest/sev-guest.c +++ b/drivers/virt/coco/sev-guest/sev-guest.c @@ -318,11 +318,11 @@ static int enc_payload(struct snp_guest_dev *snp_dev, u64 seqno, int version, u8 return __enc_payload(snp_dev, req, payload, sz); } -static int handle_guest_request(struct snp_guest_dev *snp_dev, u64 exit_code, int msg_ver, +static int handle_guest_request(struct snp_guest_dev *snp_dev, u64 exit_code, + struct snp_guest_request_ioctl *arg, u8 type, void *req_buf, size_t req_sz, void *resp_buf, - u32 resp_sz, __u64 *fw_err) + u32 resp_sz) { - unsigned long err; u64 seqno; int rc; @@ -334,7 +334,8 @@ static int handle_guest_request(struct snp_guest_dev *snp_dev, u64 exit_code, in memset(snp_dev->response, 0, sizeof(struct snp_guest_msg)); /* Encrypt the userspace provided payload */ - rc = enc_payload(snp_dev, seqno, msg_ver, type, req_buf, req_sz); + rc = enc_payload(snp_dev, seqno, arg->msg_version, type, req_buf, + req_sz); if (rc) return rc; @@ -344,7 +345,8 @@ static int handle_guest_request(struct snp_guest_dev *snp_dev, u64 exit_code, in * sequence number must be incremented or the VMPCK must be deleted to * prevent reuse of the IV. */ - rc = snp_issue_guest_request(exit_code, &snp_dev->input, &err); + rc = snp_issue_guest_request(exit_code, &snp_dev->input, + &arg->exitinfo2); /* * If the extended guest request fails due to having too small of a @@ -366,24 +368,22 @@ static int handle_guest_request(struct snp_guest_dev *snp_dev, u64 exit_code, in * of the VMPCK and the error code being propagated back to the * user as an ioctl() return code. */ - rc = snp_issue_guest_request(exit_code, &snp_dev->input, &err); + rc = snp_issue_guest_request(exit_code, &snp_dev->input, + &arg->exitinfo2); /* * Override the error to inform callers the given extended * request buffer size was too small and give the caller the * required buffer size. */ - err = SNP_GUEST_REQ_INVALID_LEN; + arg->exitinfo2 = SNP_GUEST_REQ_INVALID_LEN; snp_dev->input.data_npages = certs_npages; } - if (fw_err) - *fw_err = err; - if (rc) { dev_alert(snp_dev->dev, - "Detected error from ASP request. rc: %d, fw_err: %llu\n", - rc, *fw_err); + "Detected error from ASP request. rc: %d, exitinfo2: %llu\n", + rc, (u64)arg->exitinfo2); goto disable_vmpck; } @@ -430,9 +430,9 @@ static int get_report(struct snp_guest_dev *snp_dev, struct snp_guest_request_io if (!resp) return -ENOMEM; - rc = handle_guest_request(snp_dev, SVM_VMGEXIT_GUEST_REQUEST, arg->msg_version, + rc = handle_guest_request(snp_dev, SVM_VMGEXIT_GUEST_REQUEST, arg, SNP_MSG_REPORT_REQ, &req, sizeof(req), resp->data, - resp_len, &arg->fw_err); + resp_len); if (rc) goto e_free; @@ -470,9 +470,8 @@ static int get_derived_key(struct snp_guest_dev *snp_dev, struct snp_guest_reque if (copy_from_user(&req, (void __user *)arg->req_data, sizeof(req))) return -EFAULT; - rc = handle_guest_request(snp_dev, SVM_VMGEXIT_GUEST_REQUEST, arg->msg_version, - SNP_MSG_KEY_REQ, &req, sizeof(req), buf, resp_len, - &arg->fw_err); + rc = handle_guest_request(snp_dev, SVM_VMGEXIT_GUEST_REQUEST, arg, + SNP_MSG_KEY_REQ, &req, sizeof(req), buf, resp_len); if (rc) return rc; @@ -532,12 +531,12 @@ static int get_ext_report(struct snp_guest_dev *snp_dev, struct snp_guest_reques return -ENOMEM; snp_dev->input.data_npages = npages; - ret = handle_guest_request(snp_dev, SVM_VMGEXIT_EXT_GUEST_REQUEST, arg->msg_version, + ret = handle_guest_request(snp_dev, SVM_VMGEXIT_EXT_GUEST_REQUEST, arg, SNP_MSG_REPORT_REQ, &req.data, - sizeof(req.data), resp->data, resp_len, &arg->fw_err); + sizeof(req.data), resp->data, resp_len); /* If certs length is invalid then copy the returned length */ - if (arg->fw_err == SNP_GUEST_REQ_INVALID_LEN) { + if (arg->exitinfo2 == SNP_GUEST_REQ_INVALID_LEN) { req.certs_len = snp_dev->input.data_npages << PAGE_SHIFT; if (copy_to_user((void __user *)arg->req_data, &req, sizeof(req))) @@ -572,7 +571,7 @@ static long snp_guest_ioctl(struct file *file, unsigned int ioctl, unsigned long if (copy_from_user(&input, argp, sizeof(input))) return -EFAULT; - input.fw_err = 0xff; + input.exitinfo2 = 0xff; /* Message version must be non-zero */ if (!input.msg_version) @@ -603,7 +602,7 @@ static long snp_guest_ioctl(struct file *file, unsigned int ioctl, unsigned long mutex_unlock(&snp_cmd_mutex); - if (input.fw_err && copy_to_user(argp, &input, sizeof(input))) + if (input.exitinfo2 && copy_to_user(argp, &input, sizeof(input))) return -EFAULT; return ret; diff --git a/include/uapi/linux/sev-guest.h b/include/uapi/linux/sev-guest.h index 256aaeff7e65..52e994b68d90 100644 --- a/include/uapi/linux/sev-guest.h +++ b/include/uapi/linux/sev-guest.h @@ -52,8 +52,16 @@ struct snp_guest_request_ioctl { __u64 req_data; __u64 resp_data; - /* firmware error code on failure (see psp-sev.h) */ - __u64 fw_err; + /* bits[63:32]: VMM error code, bits[31:0] firmware error code (see psp-sev.h) */ + + union { + __u64 fw_err; /* Name deprecated in favor of others */ + sev_guestreq_err_t exitinfo2; + struct { + __u32 fw_error; + __u32 vmm_error; + }; + }; }; struct snp_ext_report_req { -- 2.39.0.314.g84b9a713c41-goog