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 X-Spam-Level: X-Spam-Status: No, score=-12.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 46EC2C433E7 for ; Mon, 19 Oct 2020 11:53:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DCF7322276 for ; Mon, 19 Oct 2020 11:53:40 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=android.com header.i=@android.com header.b="NOmBCwJX" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728387AbgJSLxj (ORCPT ); Mon, 19 Oct 2020 07:53:39 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45440 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728369AbgJSLxe (ORCPT ); Mon, 19 Oct 2020 07:53:34 -0400 Received: from mail-pg1-x543.google.com (mail-pg1-x543.google.com [IPv6:2607:f8b0:4864:20::543]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B3E5AC0613D0 for ; Mon, 19 Oct 2020 04:53:31 -0700 (PDT) Received: by mail-pg1-x543.google.com with SMTP id n9so5880045pgt.8 for ; Mon, 19 Oct 2020 04:53:31 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=android.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=EAcwqmNfAmwXwu0i3bIxz+R5/n4Ik+l7yKLbYmcgPlU=; b=NOmBCwJXEnbqMWKYp9EX+FUE3rN7d6I9+W7Ynhnl4DEacejiUrwDLCdRnPBa/GxfLs ew0NegylxLreYjG5HPKEKbOIvmzALCiwkoe/KKmhRfW1cGRSwAcWwN2/tt960eRMzSpC JIgxoo11zZU75AgazfyIL26vlZTXCDcH4R1f4nO6AOW/wFxCevWNAdvIdSK7udmaTZ9d rxbG7nb9UQ4pxhKVwB8bpH8NJwSrjU36VZaF37q25K3/3pFZ0H8lhC8Wdd5iyNZEWOj3 z1pZ8LTm+iLjkCPGpEtxgNczwDi3myTAoKIQt3RGVNQnImg2UlvxoZgfWt2hbnsP25kw QVsA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=EAcwqmNfAmwXwu0i3bIxz+R5/n4Ik+l7yKLbYmcgPlU=; b=tRzvu/7fUNWXvLglOx5w1f5edQWcrVZl6uIzyt7Cfz3xNqZl8q4aKxwXAq9dwD52b5 k3iRqM4vCT8S6DVK62tvOlIQFSiimCn57BWc8vBOFe4fgWMRAM33GAkV+tt47VGKfFjE ZJu2uTpzqfxNeQHyk7taZ+I++3747dYUINevnOdV0Upcll9vGEN68dYtHjbt/Q568Mzd Q1i4cptvSalkvlJzKOxg81J6nNWP+wrrGyPKY1FP+q47/BDt6mL4jwj8bciEX/87341y dvR2S8Pcma3zLQc812zZPoZcLH6uHwVFqm8BfncpPgPan0CQPqIVeFb2EvzFwpuwWl9i VkeA== X-Gm-Message-State: AOAM5330UjwM6G/bN4Ck2Tn3MhVqzXxjA/9SDbzBma2nxFan+tPWXsQa t+xcisdVDyGwcNp2wPy/5NKwqVTaMsrGvQ== X-Google-Smtp-Source: ABdhPJzLV5deOuiOvJDiKiswUd9e+45wYwwm0xVwiV3R4XXfSmm1D60wGrwFS//kaC1mgMkBVkh4oA== X-Received: by 2002:a65:5c86:: with SMTP id a6mr13918432pgt.227.1603108411168; Mon, 19 Oct 2020 04:53:31 -0700 (PDT) Received: from nebulus.mtv.corp.google.com ([2620:15c:211:200:4a0f:cfff:fe35:d61b]) by smtp.gmail.com with ESMTPSA id w68sm12128099pfb.108.2020.10.19.04.53.30 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 19 Oct 2020 04:53:30 -0700 (PDT) From: Mark Salyzyn To: linux-kernel@vger.kernel.org Cc: kernel-team@android.com, John Stultz , Mark Salyzyn , Stephen Smalley , linux-security-module@vger.kernel.org Subject: [PATCH v16 4/4] overlayfs: inode_owner_or_capable called during execv Date: Mon, 19 Oct 2020 04:52:39 -0700 Message-Id: <20201019115239.2732422-5-salyzyn@android.com> X-Mailer: git-send-email 2.29.0.rc1.297.gfa9743e501-goog In-Reply-To: <20201019115239.2732422-1-salyzyn@android.com> References: <20201019115239.2732422-1-salyzyn@android.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: John Stultz Using old_creds as an indication that we are not overriding the credentials, bypass call to inode_owner_or_capable. This solves a problem with all execv calls being blocked when using the caller's credentials. Signed-off-by: John Stultz Signed-off-by: Mark Salyzyn Fixes: 05acefb4872da ("ovl: check permission to open real file") To: linux-fsdevel@vger.kernel.org To: linux-unionfs@vger.kernel.org Cc: Stephen Smalley Cc: linux-kernel@vger.kernel.org Cc: linux-security-module@vger.kernel.org Cc: kernel-team@android.com v16 - introduced fix over rebased series --- fs/overlayfs/file.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/overlayfs/file.c b/fs/overlayfs/file.c index b1357bb067d9..9ab9663b02d8 100644 --- a/fs/overlayfs/file.c +++ b/fs/overlayfs/file.c @@ -53,7 +53,7 @@ static struct file *ovl_open_realfile(const struct file *file, err = inode_permission(realinode, MAY_OPEN | acc_mode); if (err) { realfile = ERR_PTR(err); - } else if (!inode_owner_or_capable(realinode)) { + } else if (old_cred && !inode_owner_or_capable(realinode)) { realfile = ERR_PTR(-EPERM); } else { realfile = open_with_fake_path(&file->f_path, flags, realinode, -- 2.29.0.rc1.297.gfa9743e501-goog