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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 87D4BC77B73 for ; Mon, 8 May 2023 11:32:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235933AbjEHLcm (ORCPT ); Mon, 8 May 2023 07:32:42 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52284 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235934AbjEHLcM (ORCPT ); Mon, 8 May 2023 07:32:12 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3D42F40206 for ; Mon, 8 May 2023 04:31:28 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id CC83A6306F for ; Mon, 8 May 2023 11:31:24 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id DAC2BC433D2; Mon, 8 May 2023 11:31:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1683545484; bh=W5b+sfXG6vdvGdFoAhDY6Q/wLz64qFKhxa/mkAulGxE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=N7q3yhOw4y2M82dVvEHhJcDsAP/CEGEZWYJ8KTOJKTt72gQN8t4XHRH6WE1xakxFZ xbMqz7K9hQbqD2SBKUIF7kQp4D5EjMbkHN7S1xv8TO9jBytwSxIPuOa6P/KraWHIxn 1wg1bSt6qhBRoEdrYIioMANAQNjUy/+pZKNLR3Q0= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Zhihao Cheng , Richard Weinberger Subject: [PATCH 5.15 054/371] ubifs: Fix memleak when insert_old_idx() failed Date: Mon, 8 May 2023 11:44:15 +0200 Message-Id: <20230508094814.212534378@linuxfoundation.org> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20230508094811.912279944@linuxfoundation.org> References: <20230508094811.912279944@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Zhihao Cheng commit b5fda08ef213352ac2df7447611eb4d383cce929 upstream. Following process will cause a memleak for copied up znode: dirty_cow_znode zn = copy_znode(c, znode); err = insert_old_idx(c, zbr->lnum, zbr->offs); if (unlikely(err)) return ERR_PTR(err); // No one refers to zn. Fetch a reproducer in [Link]. Function copy_znode() is split into 2 parts: resource allocation and znode replacement, insert_old_idx() is split in similar way, so resource cleanup could be done in error handling path without corrupting metadata(mem & disk). It's okay that old index inserting is put behind of add_idx_dirt(), old index is used in layout_leb_in_gaps(), so the two processes do not depend on each other. Link: https://bugzilla.kernel.org/show_bug.cgi?id=216705 Fixes: 1e51764a3c2a ("UBIFS: add new flash file system") Cc: stable@vger.kernel.org Signed-off-by: Zhihao Cheng Signed-off-by: Richard Weinberger Signed-off-by: Greg Kroah-Hartman --- fs/ubifs/tnc.c | 137 ++++++++++++++++++++++++++++++++++++--------------------- 1 file changed, 87 insertions(+), 50 deletions(-) --- a/fs/ubifs/tnc.c +++ b/fs/ubifs/tnc.c @@ -44,6 +44,33 @@ enum { NOT_ON_MEDIA = 3, }; +static void do_insert_old_idx(struct ubifs_info *c, + struct ubifs_old_idx *old_idx) +{ + struct ubifs_old_idx *o; + struct rb_node **p, *parent = NULL; + + p = &c->old_idx.rb_node; + while (*p) { + parent = *p; + o = rb_entry(parent, struct ubifs_old_idx, rb); + if (old_idx->lnum < o->lnum) + p = &(*p)->rb_left; + else if (old_idx->lnum > o->lnum) + p = &(*p)->rb_right; + else if (old_idx->offs < o->offs) + p = &(*p)->rb_left; + else if (old_idx->offs > o->offs) + p = &(*p)->rb_right; + else { + ubifs_err(c, "old idx added twice!"); + kfree(old_idx); + } + } + rb_link_node(&old_idx->rb, parent, p); + rb_insert_color(&old_idx->rb, &c->old_idx); +} + /** * insert_old_idx - record an index node obsoleted since the last commit start. * @c: UBIFS file-system description object @@ -69,35 +96,15 @@ enum { */ static int insert_old_idx(struct ubifs_info *c, int lnum, int offs) { - struct ubifs_old_idx *old_idx, *o; - struct rb_node **p, *parent = NULL; + struct ubifs_old_idx *old_idx; old_idx = kmalloc(sizeof(struct ubifs_old_idx), GFP_NOFS); if (unlikely(!old_idx)) return -ENOMEM; old_idx->lnum = lnum; old_idx->offs = offs; + do_insert_old_idx(c, old_idx); - p = &c->old_idx.rb_node; - while (*p) { - parent = *p; - o = rb_entry(parent, struct ubifs_old_idx, rb); - if (lnum < o->lnum) - p = &(*p)->rb_left; - else if (lnum > o->lnum) - p = &(*p)->rb_right; - else if (offs < o->offs) - p = &(*p)->rb_left; - else if (offs > o->offs) - p = &(*p)->rb_right; - else { - ubifs_err(c, "old idx added twice!"); - kfree(old_idx); - return 0; - } - } - rb_link_node(&old_idx->rb, parent, p); - rb_insert_color(&old_idx->rb, &c->old_idx); return 0; } @@ -199,23 +206,6 @@ static struct ubifs_znode *copy_znode(st __set_bit(DIRTY_ZNODE, &zn->flags); __clear_bit(COW_ZNODE, &zn->flags); - ubifs_assert(c, !ubifs_zn_obsolete(znode)); - __set_bit(OBSOLETE_ZNODE, &znode->flags); - - if (znode->level != 0) { - int i; - const int n = zn->child_cnt; - - /* The children now have new parent */ - for (i = 0; i < n; i++) { - struct ubifs_zbranch *zbr = &zn->zbranch[i]; - - if (zbr->znode) - zbr->znode->parent = zn; - } - } - - atomic_long_inc(&c->dirty_zn_cnt); return zn; } @@ -234,6 +224,42 @@ static int add_idx_dirt(struct ubifs_inf } /** + * replace_znode - replace old znode with new znode. + * @c: UBIFS file-system description object + * @new_zn: new znode + * @old_zn: old znode + * @zbr: the branch of parent znode + * + * Replace old znode with new znode in TNC. + */ +static void replace_znode(struct ubifs_info *c, struct ubifs_znode *new_zn, + struct ubifs_znode *old_zn, struct ubifs_zbranch *zbr) +{ + ubifs_assert(c, !ubifs_zn_obsolete(old_zn)); + __set_bit(OBSOLETE_ZNODE, &old_zn->flags); + + if (old_zn->level != 0) { + int i; + const int n = new_zn->child_cnt; + + /* The children now have new parent */ + for (i = 0; i < n; i++) { + struct ubifs_zbranch *child = &new_zn->zbranch[i]; + + if (child->znode) + child->znode->parent = new_zn; + } + } + + zbr->znode = new_zn; + zbr->lnum = 0; + zbr->offs = 0; + zbr->len = 0; + + atomic_long_inc(&c->dirty_zn_cnt); +} + +/** * dirty_cow_znode - ensure a znode is not being committed. * @c: UBIFS file-system description object * @zbr: branch of znode to check @@ -265,21 +291,32 @@ static struct ubifs_znode *dirty_cow_zno return zn; if (zbr->len) { - err = insert_old_idx(c, zbr->lnum, zbr->offs); - if (unlikely(err)) - return ERR_PTR(err); + struct ubifs_old_idx *old_idx; + + old_idx = kmalloc(sizeof(struct ubifs_old_idx), GFP_NOFS); + if (unlikely(!old_idx)) { + err = -ENOMEM; + goto out; + } + old_idx->lnum = zbr->lnum; + old_idx->offs = zbr->offs; + err = add_idx_dirt(c, zbr->lnum, zbr->len); - } else - err = 0; + if (err) { + kfree(old_idx); + goto out; + } - zbr->znode = zn; - zbr->lnum = 0; - zbr->offs = 0; - zbr->len = 0; + do_insert_old_idx(c, old_idx); + } + + replace_znode(c, zn, znode, zbr); - if (unlikely(err)) - return ERR_PTR(err); return zn; + +out: + kfree(zn); + return ERR_PTR(err); } /**