From patchwork Thu Oct 22 13:16:52 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mark Salyzyn X-Patchwork-Id: 11851321 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 006C714B4 for ; Thu, 22 Oct 2020 13:17:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CCA12222E9 for ; Thu, 22 Oct 2020 13:17:31 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=android.com header.i=@android.com header.b="JLICfTM8" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2899449AbgJVNR3 (ORCPT ); Thu, 22 Oct 2020 09:17:29 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50394 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2899444AbgJVNR3 (ORCPT ); Thu, 22 Oct 2020 09:17:29 -0400 Received: from mail-pg1-x542.google.com (mail-pg1-x542.google.com [IPv6:2607:f8b0:4864:20::542]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5DE38C0613CF for ; Thu, 22 Oct 2020 06:17:29 -0700 (PDT) Received: by mail-pg1-x542.google.com with SMTP id b23so923384pgb.3 for ; Thu, 22 Oct 2020 06:17:29 -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:mime-version :content-transfer-encoding; bh=95EtoPtq6IhF7jVfCLm2ubW0zmAlnuViyd/yfLI6I2Q=; b=JLICfTM8wkAkoeu/9wJXsAVQVwcIq/0L2dvY2w5FMuiWxtn/7vLcfJGTDShfA/20bI HqHj4WAUsBH6VEzGO2V/cXYVgMk8OYYYJw/fsqivUasRB9On2wnATVnNPC4enZQc0vcx 56l3i0xS7vzwIjdVptJkXjzGRpPJRU2bWXOUbhVUmXx/3rhaEeGFmyGuNdQZwsHU45LI yYNh8DHBYn29Iy07IOgOfSb1j9JEGjBM9RlqNRmt/tp8/Fze+shK8j+6Fq5D6VbfVZyX JoZaXMFo5GhVxRg6/yC3wEbfB5MkMMYioHv2WfCLSgzd1kHCZdLrZIsoe7uBgj3BLsYG 5ZNw== 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:mime-version :content-transfer-encoding; bh=95EtoPtq6IhF7jVfCLm2ubW0zmAlnuViyd/yfLI6I2Q=; b=UneFTwA89NSvwCORUbflFp7RqD+jWRCAFJt2ELEpDX/m2R/RGp18u82jNscDMJXurq 1nLbLnJeCLPPKObY04nXoEEwoDjFwBNsf6PIijY95rrROn6fDJA7dPYVDVIeLxOzCjH6 dCv36jrajmyBVi4SjvsYq8n3VjNERKpPykmQibB/zz9CD71rUikDhtEyvdCpeVWNrNUI PVwP8GRXgbc6P2gK3aLb/Uxjnphq1LWOl4nHn+OzcRdh2yBX+675p37ELUxwn3K64hg/ d09hcGpydWhJqZl5ENQ52F3+zRDccbW1HC7dNr+DjhtWNNUbmC+T7OIkwh+SLZ9jCtuF s8eQ== X-Gm-Message-State: AOAM531lR4rkC+fZXaZfyPU4mkokCGiOWcW8gX7lT9lXrE8j+tks75se Y+gol18K8uUbtvnGg4XSydTWYg== X-Google-Smtp-Source: ABdhPJyHdppZW0RFvvl0AaAOkc4OPMxfBBSE8nQVLbXo+W5/x+U7rzJWGVU+dyLXQv0nbYMASfK12A== X-Received: by 2002:a63:4d45:: with SMTP id n5mr2073942pgl.389.1603372648926; Thu, 22 Oct 2020 06:17:28 -0700 (PDT) Received: from nebulus.mtv.corp.google.com ([2620:15c:211:200:4a0f:cfff:fe35:d61b]) by smtp.gmail.com with ESMTPSA id e2sm1400401pgd.27.2020.10.22.06.17.26 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 22 Oct 2020 06:17:27 -0700 (PDT) From: Mark Salyzyn To: linux-kernel@vger.kernel.org Cc: kernel-team@android.com, John Stultz , Mark Salyzyn , linux-fsdevel@vger.kernel.org, linux-unionfs@vger.kernel.org, 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: Thu, 22 Oct 2020 06:16:52 -0700 Message-Id: <20201022131652.2784152-1-salyzyn@android.com> X-Mailer: git-send-email 2.29.0.rc1.297.gfa9743e501-goog 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") Cc: linux-fsdevel@vger.kernel.org Cc: 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,