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[2620:137:e000::1:20]) by mx.google.com with ESMTP id r29-20020a63a55d000000b0044b817adee1si1140086pgu.78.2022.11.02.18.13.42; Wed, 02 Nov 2022 18:13:55 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; dkim=pass header.i=@google.com header.s=20210112 header.b=aDP5nCCE; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=REJECT sp=REJECT dis=NONE) header.from=google.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230345AbiKCBK6 (ORCPT + 99 others); Wed, 2 Nov 2022 21:10:58 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59784 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230222AbiKCBKu (ORCPT ); Wed, 2 Nov 2022 21:10:50 -0400 Received: from mail-pj1-x1049.google.com (mail-pj1-x1049.google.com [IPv6:2607:f8b0:4864:20::1049]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 57A0E12760 for ; Wed, 2 Nov 2022 18:10:50 -0700 (PDT) Received: by mail-pj1-x1049.google.com with SMTP id q1-20020a17090aa00100b002139a592adbso2647878pjp.1 for ; Wed, 02 Nov 2022 18:10:50 -0700 (PDT) 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=/vy9fIPcvn2rwaNqM4HfeZWrqvTDpalnz2HwsiIC1NU=; b=aDP5nCCE3d4x1FyofAIpujyLzNhqQX5ACcKmQzD89IqR+y5Fb5ybFRrypKxfYh/sRd 5Jud/kEPqc3U82bG4IL/QiQN6j28f9ih7EOka58yWZbrqL8pWAnkKn7+9nb5nECpm7Lo MuFMPJ8/0L1nhRQOw7YcO0ONsRWg8esIjYcjn1V07njqfMFk0z58RpdSMLACtlTZrVu2 rqpJ77/U5q7sj8jII1ZCxdH647mhOq74v8S84VEl/Up0SyDT0HjJgHJRretO4oT4AAvN KWQcNf3zR+Ytu8AKJwadHs/NJ18EHTEFJ/Gx3f4hlXNoIhxUqujJ96saSE5wy0/SMpVc NhTw== 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=/vy9fIPcvn2rwaNqM4HfeZWrqvTDpalnz2HwsiIC1NU=; b=Qvnh599yOTXeucu4nRp5dcwyhPV0WCKRug/JbmJBfgjGF+XhLWlR40JqEAhn1aNWb/ mgMZ4Q4HVHTILEzbzbtjQj3zwdwmWGp+3j2YT4xJrAfrXSXKCH6HYPC4IrUmbjZaH239 anNup839SQhkb9Y2XnhLr2yBT0+mJW+0sXFgf2oGu5yL/k0PbA7cuRzqyfOrU/Q4al0y /TzxkIM1Vae6b65IV3vgnATtj8mp8GbM2k0muSSpHrOWOfPK62ptpAzbVMCj+UU8Es4B uX/GaBahJry5ZNhLMZNWj17RqecHlc5e1NrMtroOp4sFA3/xU379jgrHaX53A9QDg3MB jX2A== X-Gm-Message-State: ACrzQf30byTdlrcEwWqy9HjiQrv2Yi6c3ob5CC55U8+BX2bNJNHxKyvD wTroL7uWhwU51GSPKlBdIGUFrolNTgnacAvLp/OR3vU7i/IFb68vt5Mfz4MjOfvWx6KiMPjGPrj MRu5n1nrnNFYy61H4BotLvbRZwP5JMolxTsOyR6ATWEeuZwE/EndiCNxcT2gimBTZHbXBxSeVYo 530IJ0lng= X-Received: from dionnaglaze.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:2ee6]) (user=dionnaglaze job=sendgmr) by 2002:a17:90a:304b:b0:213:d60f:7fc6 with SMTP id q11-20020a17090a304b00b00213d60f7fc6mr20298759pjl.92.1667437849701; Wed, 02 Nov 2022 18:10:49 -0700 (PDT) Date: Thu, 3 Nov 2022 01:10:37 +0000 In-Reply-To: <20221103011038.1542614-1-dionnaglaze@google.com> Mime-Version: 1.0 References: <20221103011038.1542614-1-dionnaglaze@google.com> X-Mailer: git-send-email 2.38.1.273.g43a17bfeac-goog Message-ID: <20221103011038.1542614-4-dionnaglaze@google.com> Subject: [PATCH v6 3/4] 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 X-Spam-Status: No, score=-9.6 required=5.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_NONE, SPF_HELO_NONE,SPF_PASS,USER_IN_DEF_DKIM_WL autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-getmail-retrieved-from-mailbox: =?utf-8?q?INBOX?= X-GMAIL-THRID: =?utf-8?q?1748435505587340863?= X-GMAIL-MSGID: =?utf-8?q?1748435505587340863?= 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 we do that. Since the issue_request's signature has changed fw_err to exitinfo2, we change the argument name here. 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") Signed-off-by: Dionna Glaze --- drivers/virt/coco/sev-guest/sev-guest.c | 7 ++----- 1 file changed, 2 insertions(+), 5 deletions(-) diff --git a/drivers/virt/coco/sev-guest/sev-guest.c b/drivers/virt/coco/sev-guest/sev-guest.c index f422f9c58ba7..0508c2f46f6b 100644 --- a/drivers/virt/coco/sev-guest/sev-guest.c +++ b/drivers/virt/coco/sev-guest/sev-guest.c @@ -303,9 +303,8 @@ static int enc_payload(struct snp_guest_dev *snp_dev, u64 seqno, int version, u8 static int handle_guest_request(struct snp_guest_dev *snp_dev, u64 exit_code, int msg_ver, u8 type, void *req_buf, size_t req_sz, void *resp_buf, - u32 resp_sz, __u64 *fw_err) + u32 resp_sz, __u64 *exitinfo2) { - unsigned long err; u64 seqno; int rc; @@ -322,9 +321,7 @@ static int handle_guest_request(struct snp_guest_dev *snp_dev, u64 exit_code, in return rc; /* Call firmware to process the request */ - rc = snp_issue_guest_request(exit_code, &snp_dev->input, &err); - if (fw_err) - *fw_err = err; + rc = snp_issue_guest_request(exit_code, &snp_dev->input, exitinfo2); if (rc) return rc;