From patchwork Wed Oct 21 15:19:03 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mark Salyzyn X-Patchwork-Id: 11849335 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 98CB814B7 for ; Wed, 21 Oct 2020 15:20:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7339B2177B for ; Wed, 21 Oct 2020 15:20:00 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=android.com header.i=@android.com header.b="Lg4SyFJr" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2502349AbgJUPT7 (ORCPT ); Wed, 21 Oct 2020 11:19:59 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44840 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2502344AbgJUPT6 (ORCPT ); Wed, 21 Oct 2020 11:19:58 -0400 Received: from mail-pj1-x1041.google.com (mail-pj1-x1041.google.com [IPv6:2607:f8b0:4864:20::1041]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7D3B9C0613CE for ; Wed, 21 Oct 2020 08:19:58 -0700 (PDT) Received: by mail-pj1-x1041.google.com with SMTP id l2so1289959pjt.5 for ; Wed, 21 Oct 2020 08:19:58 -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=5hmO+mhbzoYH/GVwbytgH/sAwdgqzz47G17aTAhhRQ8=; b=Lg4SyFJrAGKmMg6tKEON5sq5UQvRWRT9njDtU86HrhpkL0D0RdFN95O/iD+u7kC/4r ahEy6DJB22RvhcXOWtpd4G1oxyqNVqToJqGqqUs1YqCpH2pXiY1c5d/0pzhbzSnYT69M nqknNaLQF80VCLDCS9BeJ3heSe/9QtMbQljDx+DCvH0VNLMd/6p9Qqsw79r2qTLa69LX R/bAIsTRcvhLiUbCjOhNRPhWsBrblxRy6nLLJDIlIAzaR7RQCmbvWYcaM06CO7pnHIQI 4XcufkDp9mMo7ZlREAiInwPH2LB+50E15mLIPFIh/Q71X2Y7y1PHShJVIl54u4zodyis BSGQ== 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=5hmO+mhbzoYH/GVwbytgH/sAwdgqzz47G17aTAhhRQ8=; b=UjDc333GCJZZ7DQ7LSfjJuE8AStR6BNd8wGoIAxklNfUPtQSoObkSn1g1THpiX/pGP 1aQHcnGUTZkk7syRjoKT+EAMJAUQLgfZg1corgOAzEz99lbOjjPBzJwnAYw/2b5Cg1ee C53jYOgrWH2smGE+lpPQ6bf4TTjeBHnV+F+dAJXrBNIH/+GkgKz8cPYUm2KXUhYQ79+K AGrObdpNo8q19F/jyE4ObwnilPJ9bn/MpqAeNgHrCPFJLu12cnYfZgtoyyCTz9D/eDhu Epla/0y5mjEwTKG+yPDNGRI6dk5fNF/fseRP9oXQL8DnFSP1vqSE1r18x8/b2H8sG0eP Gc6w== X-Gm-Message-State: AOAM532wCLcd9c/5HoQU6ao5+OroJImEeyCb6xi4eV8JboWRPwkTexID hR7vTDtrNWv9idSP/TPNNI0SsA== X-Google-Smtp-Source: ABdhPJz/qcBUTmMYFz604l9m4rFbwcPGK6tFrbID3W5xqQgE0s1q2+B4QDvOzg5odG59Fj+FHRoowg== X-Received: by 2002:a17:902:c24b:b029:d3:f3e6:1915 with SMTP id 11-20020a170902c24bb02900d3f3e61915mr4132119plg.56.1603293598087; Wed, 21 Oct 2020 08:19:58 -0700 (PDT) Received: from nebulus.mtv.corp.google.com ([2620:15c:211:200:4a0f:cfff:fe35:d61b]) by smtp.gmail.com with ESMTPSA id s10sm2409646pji.7.2020.10.21.08.19.57 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 21 Oct 2020 08:19:57 -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, selinux@vger.kernel.org Subject: [RESEND PATCH v18 4/4] overlayfs: inode_owner_or_capable called during execv Date: Wed, 21 Oct 2020 08:19:03 -0700 Message-Id: <20201021151903.652827-5-salyzyn@android.com> X-Mailer: git-send-email 2.29.0.rc1.297.gfa9743e501-goog In-Reply-To: <20201021151903.652827-1-salyzyn@android.com> References: <20201021151903.652827-1-salyzyn@android.com> MIME-Version: 1.0 Precedence: bulk List-ID: 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") C: linux-fsdevel@vger.kernel.org C: 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 Cc: selinux@vger.kernel.org v18 - rebase 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,