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 60C1EC388F7 for ; Tue, 20 Oct 2020 19:18:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 05EFC22251 for ; Tue, 20 Oct 2020 19:18:06 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=android.com header.i=@android.com header.b="B7i2YxzQ" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2438083AbgJTTSG (ORCPT ); Tue, 20 Oct 2020 15:18:06 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56792 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2438061AbgJTTSA (ORCPT ); Tue, 20 Oct 2020 15:18:00 -0400 Received: from mail-pf1-x441.google.com (mail-pf1-x441.google.com [IPv6:2607:f8b0:4864:20::441]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6A271C0613D6 for ; Tue, 20 Oct 2020 12:18:00 -0700 (PDT) Received: by mail-pf1-x441.google.com with SMTP id w21so1731405pfc.7 for ; Tue, 20 Oct 2020 12:18:00 -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=VhB4D3Qqks0KHT6wFulg0fVFOaiWDpRKJPkxF+EjUPY=; b=B7i2YxzQiX4ywyIQ7T2IluxWtdSzbMHDa7gjsTvpnwiCmX/zVEnzH0+Zi0DMEBnVwQ PFqs4GQSDMqkpZXfOQ+wQT3i1MR7BVH0bDQygYEZn3UopGZRsYU0jSbhPu9FoKMoaQOK R8/yZdGPnVkb9RsyMKUZbJLN1SvfBTz2gnhpMvoQkz+aM9U7ARA/dTMAT/bs/2TsfT3q sCSMMI9/sMP03LgEVwuNOlEe2ySrWYraI2bHU6T94VKrQ1X5S43qxqmV03MchyqqfhsC gxAjGIS4Ao/3u7zz9qVEG4G+Qt+bbFsd6dgZm4Ml/yrFU1Ajy5wUKv9Bs43UF0DET7bP owhA== 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=VhB4D3Qqks0KHT6wFulg0fVFOaiWDpRKJPkxF+EjUPY=; b=bNp+1Emu1Y/CMQcW6RoRqpSLElFm9Sdjo2wXqNn3uwf74R4/zAA+X0G9eFuL9ywZXd FjSqgZtKCS2kBfO4yplVfwSrLMj/Wia5muRS/4S1NfgY9psKnSIVRa4u+smyEXoOy0Fx z42/JvcgX5js/xP9efJlWuYZIhhTnmtqG7WzuC4bfz+B3NSq05FwDwVa/6GoDlv1iym+ PKi9YO3sajw1LXqONeMH2QjG7iYpQkaC+ktrGaxgcu9D0Zt16OIpEuJUkBWEtmAh0Wd4 7iEv2fRuNcFgtpPS5ADnUXr0d7vEOuV/NZKgT0qK/CaaMR6az0aeWBnG7iNj9pZ6l6Yg zbqg== X-Gm-Message-State: AOAM532/Z/+vi+YBYIHCQkNFOrOT31ZritaZycEmvl1PIjrW/yYKsLAe Q0RxHyOxCllsG9/OuvcL7RfaL2ASN6/l3A== X-Google-Smtp-Source: ABdhPJweqU78LH8AyiJYMHFlFTspVNfLD1dRowEZwySv0syk1hVhU7wNYb+7SLKhooDpuEc82uDo2Q== X-Received: by 2002:a62:8348:0:b029:152:9d3c:c67e with SMTP id h69-20020a6283480000b02901529d3cc67emr1355225pfe.65.1603221479830; Tue, 20 Oct 2020 12:17:59 -0700 (PDT) Received: from nebulus.mtv.corp.google.com ([2620:15c:211:200:4a0f:cfff:fe35:d61b]) by smtp.gmail.com with ESMTPSA id 204sm2855995pfz.74.2020.10.20.12.17.58 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 20 Oct 2020 12:17:58 -0700 (PDT) From: Mark Salyzyn To: linux-kernel@vger.kernel.org Cc: kernel-team@android.com, Mark Salyzyn , John Stultz , Stephen Smalley , linux-security-module@vger.kernel.org Subject: [PATCH v17 4/4] overlayfs: inode_owner_or_capable called during execv Date: Tue, 20 Oct 2020 12:17:32 -0700 Message-Id: <20201020191732.4049987-5-salyzyn@android.com> X-Mailer: git-send-email 2.29.0.rc1.297.gfa9743e501-goog In-Reply-To: <20201020191732.4049987-1-salyzyn@android.com> References: <20201020191732.4049987-1-salyzyn@android.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 v17 - rebase 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