From nobody Mon Feb 9 07:20:39 2026 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.13]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 9AB2A17DFF1; Thu, 22 Aug 2024 01:25:41 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.13 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1724289943; cv=none; b=Itf1AHqRFoBIfHIWad2Mpu2h3SBUTeZaHEpWniSpq7jSyIEL+Jxe/W1v4S/kp+A5bInj0C4ENnIOgW3HKVu+kMDBQz7aCdQ0ezHm6tcJEtrrlYBTkVq1hFZpdmuN9pJyYNlp9+wmnkSq/nTnpIZwQhIt3WfmCbRyWLCIoCdEUkM= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1724289943; c=relaxed/simple; bh=Ab06tqTimEBOVZ57yicpTqqHZTz/fm/bVSgF/YElcBo=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=sl6K8JnkydSikT3xMFL+FW+labpMYfZZTcZ4VX6EgAdHuO9L9UaokVYt64DEHlBiJV7Oo7rO/WgPr3I6ATIUYR6iiWaDA4n8wfusHheAhBNK9/3Nm8u4sUlPbiL/88eypXfMIsMNmSrZk14r/4C0gjrzMk2p5MXlN8ydxxX4s8Y= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com; spf=pass smtp.mailfrom=intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=gD6JLkuC; arc=none smtp.client-ip=192.198.163.13 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="gD6JLkuC" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1724289942; x=1755825942; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=Ab06tqTimEBOVZ57yicpTqqHZTz/fm/bVSgF/YElcBo=; b=gD6JLkuCLVxmPUTAzvxrdyFsNAktIyRj4r7JcgVP9px97Y2lNiEJpqdw YCw0gmCErXXS5e22z700m7lou5t8QyT7h3OFnplfZOPyWjg4SHFveJ2vL mg6uSJoN03c1yGWhsVu0SoX1bVksQh4gEiFRcW/Be1E8ecboq/pmCpfpc hCFyMYlYNGI6dkSXfOUtDFOXWcRFqpdm0GNr29oakw9d1q1B8HS9gMGUw 4j/sgPt7sRsK6jxKrJ/s66vcN8VsrhW/a5bdr3mTqZNuxgukR0CBnl9J5 ZE6MCmaF43fNkHPYiNSnNbgrwLzFSbaOAIq+S4atuf13xLnWsmx1uFchp w==; X-CSE-ConnectionGUID: 4cSWJ+uPRHeZM+w5Ky52xg== X-CSE-MsgGUID: sugbZ8IDTBeii84SS6r5TA== X-IronPort-AV: E=McAfee;i="6700,10204,11171"; a="25574771" X-IronPort-AV: E=Sophos;i="6.10,165,1719903600"; d="scan'208";a="25574771" Received: from orviesa007.jf.intel.com ([10.64.159.147]) by fmvoesa107.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 21 Aug 2024 18:25:33 -0700 X-CSE-ConnectionGUID: VCiGVqUCSTCOATsjMoRokQ== X-CSE-MsgGUID: UmESM1nbQEq1rqf37twETw== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.10,165,1719903600"; d="scan'208";a="61811057" Received: from unknown (HELO vcostago-mobl3.jf.intel.com) ([10.241.225.92]) by orviesa007-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 21 Aug 2024 18:25:32 -0700 From: Vinicius Costa Gomes To: brauner@kernel.org, amir73il@gmail.com, hu1.chen@intel.com Cc: miklos@szeredi.hu, malini.bhandaru@intel.com, tim.c.chen@intel.com, mikko.ylinen@intel.com, lizhen.you@intel.com, linux-unionfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, Vinicius Costa Gomes Subject: [PATCH v2 12/16] overlayfs/namei: Convert to cred_guard() Date: Wed, 21 Aug 2024 18:25:19 -0700 Message-ID: <20240822012523.141846-13-vinicius.gomes@intel.com> X-Mailer: git-send-email 2.46.0 In-Reply-To: <20240822012523.141846-1-vinicius.gomes@intel.com> References: <20240822012523.141846-1-vinicius.gomes@intel.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Replace the override_creds_light()/revert_creds_light() pairs of operations with cred_guard()/cred_scoped_guard(). Only ovl_maybe_lookup_lowerdata() use cred_scoped_guard(), because of 'goto', which can cause the cleanup flow to run on garbage memory. Signed-off-by: Vinicius Costa Gomes --- fs/overlayfs/namei.c | 20 +++++--------------- 1 file changed, 5 insertions(+), 15 deletions(-) diff --git a/fs/overlayfs/namei.c b/fs/overlayfs/namei.c index e52d6ae8eeb5..723731bc3678 100644 --- a/fs/overlayfs/namei.c +++ b/fs/overlayfs/namei.c @@ -953,15 +953,12 @@ static int ovl_maybe_validate_verity(struct dentry *d= entry) return err; =20 if (!ovl_test_flag(OVL_VERIFIED_DIGEST, inode)) { - const struct cred *old_cred; - - old_cred =3D ovl_override_creds_light(dentry->d_sb); + cred_guard(ovl_creds(dentry->d_sb)); =20 err =3D ovl_validate_verity(ofs, &metapath, &datapath); if (err =3D=3D 0) ovl_set_flag(OVL_VERIFIED_DIGEST, inode); =20 - revert_creds_light(old_cred); } =20 ovl_inode_unlock(inode); @@ -975,7 +972,6 @@ static int ovl_maybe_lookup_lowerdata(struct dentry *de= ntry) struct inode *inode =3D d_inode(dentry); const char *redirect =3D ovl_lowerdata_redirect(inode); struct ovl_path datapath =3D {}; - const struct cred *old_cred; int err; =20 if (!redirect || ovl_dentry_lowerdata(dentry)) @@ -993,9 +989,8 @@ static int ovl_maybe_lookup_lowerdata(struct dentry *de= ntry) if (ovl_dentry_lowerdata(dentry)) goto out; =20 - old_cred =3D ovl_override_creds_light(dentry->d_sb); - err =3D ovl_lookup_data_layers(dentry, redirect, &datapath); - revert_creds_light(old_cred); + cred_scoped_guard(ovl_creds(dentry->d_sb)) + err =3D ovl_lookup_data_layers(dentry, redirect, &datapath); if (err) goto out_err; =20 @@ -1030,7 +1025,6 @@ struct dentry *ovl_lookup(struct inode *dir, struct d= entry *dentry, unsigned int flags) { struct ovl_entry *oe =3D NULL; - const struct cred *old_cred; struct ovl_fs *ofs =3D OVL_FS(dentry->d_sb); struct ovl_entry *poe =3D OVL_E(dentry->d_parent); struct ovl_entry *roe =3D OVL_E(dentry->d_sb->s_root); @@ -1061,7 +1055,7 @@ struct dentry *ovl_lookup(struct inode *dir, struct d= entry *dentry, if (dentry->d_name.len > ofs->namelen) return ERR_PTR(-ENAMETOOLONG); =20 - old_cred =3D ovl_override_creds_light(dentry->d_sb); + cred_guard(ovl_creds(dentry->d_sb)); upperdir =3D ovl_dentry_upper(dentry->d_parent); if (upperdir) { d.layer =3D &ofs->layers[0]; @@ -1342,7 +1336,6 @@ struct dentry *ovl_lookup(struct inode *dir, struct d= entry *dentry, =20 ovl_dentry_init_reval(dentry, upperdentry, OVL_I_E(inode)); =20 - revert_creds_light(old_cred); if (origin_path) { dput(origin_path->dentry); kfree(origin_path); @@ -1366,7 +1359,6 @@ struct dentry *ovl_lookup(struct inode *dir, struct d= entry *dentry, kfree(upperredirect); out: kfree(d.redirect); - revert_creds_light(old_cred); return ERR_PTR(err); } =20 @@ -1374,7 +1366,6 @@ bool ovl_lower_positive(struct dentry *dentry) { struct ovl_entry *poe =3D OVL_E(dentry->d_parent); const struct qstr *name =3D &dentry->d_name; - const struct cred *old_cred; unsigned int i; bool positive =3D false; bool done =3D false; @@ -1390,7 +1381,7 @@ bool ovl_lower_positive(struct dentry *dentry) if (!ovl_dentry_upper(dentry)) return true; =20 - old_cred =3D ovl_override_creds_light(dentry->d_sb); + cred_guard(ovl_creds(dentry->d_sb)); /* Positive upper -> have to look up lower to see whether it exists */ for (i =3D 0; !done && !positive && i < ovl_numlower(poe); i++) { struct dentry *this; @@ -1423,7 +1414,6 @@ bool ovl_lower_positive(struct dentry *dentry) dput(this); } } - revert_creds_light(old_cred); =20 return positive; } --=20 2.46.0