From patchwork Thu Feb 9 21:28:35 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Richard Weinberger X-Patchwork-Id: 726337 X-Patchwork-Delegate: richard@nod.at Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from bombadil.infradead.org (bombadil.infradead.org [65.50.211.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 3vKB7H02sCz9s7q for ; Fri, 10 Feb 2017 08:30:03 +1100 (AEDT) Authentication-Results: ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="BfYAYppX"; dkim-atps=neutral DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:MIME-Version:Cc:List-Subscribe: List-Help:List-Post:List-Archive:List-Unsubscribe:List-Id:References: In-Reply-To:Message-Id:Date:Subject:To:From:Reply-To:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Owner; bh=hppE1yA7QKxNxsYoEO1gxfjnamXMbyBHQa9TWKuwBiY=; b=BfYAYppXFPIXDxEphylzcghqcl D5Ms70Kak95kLnxQbEtACswjj3Vj6meg5gif+2aeXZ5wGdcKjSFOftCxIVJmtLrbLaqbomEDCX/Je IEidqDg0ayDgBlHvQCdL/NywDKek/KtdJUsS4H02FTJeiSo1PboAAlWoQfJ1ggGjHfCjtDf1c99+e Xthq+4CfyTsvNe/dyV+kOE+xWibIaRRp9bXNMT2OdZF9qKiZtEeREwNSl9ysVXg11O+mMrFhYlrKV RHb5BwKp5/TodS+r81AKzJtsMqsfU6zAwdn3I/TghQYvGuUsZll/h0tzrdOoQMi6Yd4a6N50ECM/W fKJ8g+7Q==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.87 #1 (Red Hat Linux)) id 1cbwHw-0006zG-Mi; Thu, 09 Feb 2017 21:30:00 +0000 Received: from mail.sigma-star.at ([95.130.255.111]) by bombadil.infradead.org with esmtp (Exim 4.87 #1 (Red Hat Linux)) id 1cbwH3-0006Aw-SX for linux-mtd@lists.infradead.org; Thu, 09 Feb 2017 21:29:12 +0000 Received: from localhost (localhost.localdomain [127.0.0.1]) by mail.sigma-star.at (Postfix) with ESMTP id 515FE24E0003; Thu, 9 Feb 2017 22:28:42 +0100 (CET) Received: from spankyham.sigmapriv.at (unknown [82.150.214.13]) by mail.sigma-star.at (Postfix) with ESMTPSA id 8DBF824E0002; Thu, 9 Feb 2017 22:28:41 +0100 (CET) From: Richard Weinberger To: linux-mtd@lists.infradead.org Subject: [PATCH 2/4] ubifs: Fix unlink code wrt. double hash lookups Date: Thu, 9 Feb 2017 22:28:35 +0100 Message-Id: <20170209212837.14197-2-richard@nod.at> X-Mailer: git-send-email 2.10.2 In-Reply-To: <20170209212837.14197-1-richard@nod.at> References: <20170209212837.14197-1-richard@nod.at> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20170209_132906_320306_24B56383 X-CRM114-Status: GOOD ( 15.96 ) X-Spam-Score: -1.9 (-) X-Spam-Report: SpamAssassin version 3.4.1 on bombadil.infradead.org summary: Content analysis details: (-1.9 points) pts rule name description ---- ---------------------- -------------------------------------------------- -0.0 SPF_PASS SPF: sender matches SPF record -1.9 BAYES_00 BODY: Bayes spam probability is 0 to 1% [score: 0.0000] X-BeenThere: linux-mtd@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Richard Weinberger , david.oberhollenzer@sigma-star.at, linux-kernel@vger.kernel.org, dedekind1@gmail.com MIME-Version: 1.0 Sender: "linux-mtd" Errors-To: linux-mtd-bounces+incoming=patchwork.ozlabs.org@lists.infradead.org When removing an encrypted file with a long anem and without having the key we have to be able to locate and remove the directory entry via a double hash. This corner case was simply forgotten. Reported-by: David Oberhollenzer Signed-off-by: Richard Weinberger --- fs/ubifs/journal.c | 10 ++++- fs/ubifs/tnc.c | 129 ++++++++++++++++++++++++++++++++++++++++++++--------- fs/ubifs/ubifs.h | 2 + 3 files changed, 117 insertions(+), 24 deletions(-) diff --git a/fs/ubifs/journal.c b/fs/ubifs/journal.c index f3b620cbdda4..7aef413ea2a9 100644 --- a/fs/ubifs/journal.c +++ b/fs/ubifs/journal.c @@ -585,7 +585,10 @@ int ubifs_jnl_update(struct ubifs_info *c, const struct inode *dir, if (!xent) { dent->ch.node_type = UBIFS_DENT_NODE; - dent_key_init(c, &dent_key, dir->i_ino, nm); + if (nm->hash) + dent_key_init_hash(c, &dent_key, dir->i_ino, nm->hash); + else + dent_key_init(c, &dent_key, dir->i_ino, nm); } else { dent->ch.node_type = UBIFS_XENT_NODE; xent_key_init(c, &dent_key, dir->i_ino, nm); @@ -629,7 +632,10 @@ int ubifs_jnl_update(struct ubifs_info *c, const struct inode *dir, kfree(dent); if (deletion) { - err = ubifs_tnc_remove_nm(c, &dent_key, nm); + if (nm->hash) + err = ubifs_tnc_remove_dh(c, &dent_key, nm->minor_hash); + else + err = ubifs_tnc_remove_nm(c, &dent_key, nm); if (err) goto out_ro; err = ubifs_add_dirt(c, lnum, dlen); diff --git a/fs/ubifs/tnc.c b/fs/ubifs/tnc.c index 709aa098dd46..d84f4ba467a3 100644 --- a/fs/ubifs/tnc.c +++ b/fs/ubifs/tnc.c @@ -1880,48 +1880,65 @@ int ubifs_tnc_lookup_nm(struct ubifs_info *c, const union ubifs_key *key, return do_lookup_nm(c, key, node, nm); } -static int do_lookup_dh(struct ubifs_info *c, const union ubifs_key *key, - struct ubifs_dent_node *dent, uint32_t cookie) +static int search_dh_cookie(struct ubifs_info *c, const union ubifs_key *key, + struct ubifs_dent_node *dent, uint32_t cookie, + struct ubifs_znode **zn, int *n) { - int n, err, type = key_type(c, key); - struct ubifs_znode *znode; + int err; + struct ubifs_znode *znode = *zn; struct ubifs_zbranch *zbr; - union ubifs_key *dkey, start_key; - - ubifs_assert(is_hash_key(c, key)); - - lowest_dent_key(c, &start_key, key_inum(c, key)); - - mutex_lock(&c->tnc_mutex); - err = ubifs_lookup_level0(c, &start_key, &znode, &n); - if (unlikely(err < 0)) - goto out_unlock; + union ubifs_key *dkey; for (;;) { if (!err) { - err = tnc_next(c, &znode, &n); + err = tnc_next(c, &znode, n); if (err) - goto out_unlock; + goto out; } - zbr = &znode->zbranch[n]; + zbr = &znode->zbranch[*n]; dkey = &zbr->key; if (key_inum(c, dkey) != key_inum(c, key) || - key_type(c, dkey) != type) { + key_type(c, dkey) != key_type(c, key)) { err = -ENOENT; - goto out_unlock; + goto out; } err = tnc_read_hashed_node(c, zbr, dent); if (err) - goto out_unlock; + goto out; if (key_hash(c, key) == key_hash(c, dkey) && - le32_to_cpu(dent->cookie) == cookie) - goto out_unlock; + le32_to_cpu(dent->cookie) == cookie) { + *zn = znode; + goto out; + } } +out: + + return err; +} + +static int do_lookup_dh(struct ubifs_info *c, const union ubifs_key *key, + struct ubifs_dent_node *dent, uint32_t cookie) +{ + int n, err; + struct ubifs_znode *znode; + union ubifs_key start_key; + + ubifs_assert(is_hash_key(c, key)); + + lowest_dent_key(c, &start_key, key_inum(c, key)); + + mutex_lock(&c->tnc_mutex); + err = ubifs_lookup_level0(c, &start_key, &znode, &n); + if (unlikely(err < 0)) + goto out_unlock; + + err = search_dh_cookie(c, key, dent, cookie, &znode, &n); + out_unlock: mutex_unlock(&c->tnc_mutex); return err; @@ -2663,6 +2680,74 @@ int ubifs_tnc_remove_nm(struct ubifs_info *c, const union ubifs_key *key, } /** + * ubifs_tnc_remove_dh - remove an index entry for a "double hashed" node. + * @c: UBIFS file-system description object + * @key: key of node + * @cookie: node cookie for collision resolution + * + * Returns %0 on success or negative error code on failure. + */ +int ubifs_tnc_remove_dh(struct ubifs_info *c, const union ubifs_key *key, + uint32_t cookie) +{ + int n, err; + struct ubifs_znode *znode; + struct ubifs_dent_node *dent; + struct ubifs_zbranch *zbr; + + if (!c->double_hash) + return -EOPNOTSUPP; + + mutex_lock(&c->tnc_mutex); + err = lookup_level0_dirty(c, key, &znode, &n); + if (err <= 0) + goto out_unlock; + + zbr = &znode->zbranch[n]; + dent = kmalloc(UBIFS_MAX_DENT_NODE_SZ, GFP_NOFS); + if (!dent) { + err = -ENOMEM; + goto out_unlock; + } + + err = tnc_read_hashed_node(c, zbr, dent); + if (err) + goto out_free; + + /* If the cookie does not match, we're facing a hash collision. */ + if (le32_to_cpu(dent->cookie) != cookie) { + union ubifs_key start_key; + + lowest_dent_key(c, &start_key, key_inum(c, key)); + + err = ubifs_lookup_level0(c, &start_key, &znode, &n); + if (unlikely(err < 0)) + goto out_unlock; + + err = search_dh_cookie(c, key, dent, cookie, &znode, &n); + if (err) + goto out_free; + } + + if (znode->cnext || !ubifs_zn_dirty(znode)) { + znode = dirty_cow_bottom_up(c, znode); + if (IS_ERR(znode)) { + err = PTR_ERR(znode); + goto out_unlock; + } + } + err = tnc_delete(c, znode, n); + +out_free: + kfree(dent); +out_unlock: + if (!err) + err = dbg_check_tnc(c, 0); + mutex_unlock(&c->tnc_mutex); + return err; +} + +/** * key_in_range - determine if a key falls within a range of keys. * @c: UBIFS file-system description object * @key: key to check diff --git a/fs/ubifs/ubifs.h b/fs/ubifs/ubifs.h index ca72382ce6cc..36df4613b803 100644 --- a/fs/ubifs/ubifs.h +++ b/fs/ubifs/ubifs.h @@ -1589,6 +1589,8 @@ int ubifs_tnc_add_nm(struct ubifs_info *c, const union ubifs_key *key, int ubifs_tnc_remove(struct ubifs_info *c, const union ubifs_key *key); int ubifs_tnc_remove_nm(struct ubifs_info *c, const union ubifs_key *key, const struct fscrypt_name *nm); +int ubifs_tnc_remove_dh(struct ubifs_info *c, const union ubifs_key *key, + uint32_t cookie); int ubifs_tnc_remove_range(struct ubifs_info *c, union ubifs_key *from_key, union ubifs_key *to_key); int ubifs_tnc_remove_ino(struct ubifs_info *c, ino_t inum);