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[2620:137:e000::1:20]) by mx.google.com with ESMTP id q25-20020a637519000000b004e3ec4b2fbasi16120113pgc.301.2023.02.02.07.22.31; Thu, 02 Feb 2023 07:22:44 -0800 (PST) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; dkim=pass header.i=@163.com header.s=s110527 header.b=M5iWNZym; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=163.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232238AbjBBPP3 (ORCPT + 99 others); Thu, 2 Feb 2023 10:15:29 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59586 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231478AbjBBPP0 (ORCPT ); Thu, 2 Feb 2023 10:15:26 -0500 Received: from m12.mail.163.com (m12.mail.163.com [220.181.12.214]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id D111C3D098; Thu, 2 Feb 2023 07:15:19 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=163.com; s=s110527; h=From:Subject:Date:Message-Id:MIME-Version; bh=wSfRI j362vJ0u/qgNuMrq21yZt2+hGp46cOVRkgR3GM=; b=M5iWNZym1pAhAlsXW/vIm VRhr+DpzCptnvi9DYlCfh81Ko+GUpd1nyj9rUZ7Fpi3tfkjxOXq72vQUo2w++wA9 /0mX0N3qsLQuTLhaRokiq89IltvvDZUmEqyBijZvLJGy1Gu535ineFHrZ7n9u8OL piRKF4WsyBJ/6BIPjSWAJ4= Received: from leanderwang-LC2.localdomain (unknown [111.206.145.21]) by zwqz-smtp-mta-g0-0 (Coremail) with SMTP id _____wDHxV1509tjVlJaCg--.49388S2; Thu, 02 Feb 2023 23:15:06 +0800 (CST) From: Zheng Wang To: colyli@suse.de Cc: hackerzheng666@gmail.com, kent.overstreet@gmail.com, linux-bcache@vger.kernel.org, linux-kernel@vger.kernel.org, alex000young@gmail.com, Zheng Wang Subject: [PATCH] bcache: Fix __bch_btree_node_alloc to make the failure behavior consistent Date: Thu, 2 Feb 2023 23:15:04 +0800 Message-Id: <20230202151504.542958-1-zyytlz.wz@163.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 X-CM-TRANSID: _____wDHxV1509tjVlJaCg--.49388S2 X-Coremail-Antispam: 1Uf129KBjvJXoWxArykKw15Ar4fWr13WryfJFb_yoW5Gr45pF W29ryYyr93Xw4UCF95G3WqvF9Yvw1jvFWUKas3u3WSvr9rAr1fCFWj9ry8ZryUCrWxWF4a vr48tw1UXr1jkF7anT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDUYxBIdaVFxhVjvjDU0xZFpf9x0ziJUU8UUUUU= X-Originating-IP: [111.206.145.21] X-CM-SenderInfo: h2113zf2oz6qqrwthudrp/1tbiGh0KU1aEEJG6+AAAsP X-Spam-Status: No, score=-2.1 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,FREEMAIL_FROM,SPF_HELO_NONE, SPF_PASS autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-getmail-retrieved-from-mailbox: =?utf-8?q?INBOX?= X-GMAIL-THRID: =?utf-8?q?1756733232056317224?= X-GMAIL-MSGID: =?utf-8?q?1756733232056317224?= In some specific situation, the return value of __bch_btree_node_alloc may be NULL. This may lead to poential NULL pointer dereference in caller function like a calling chaion : btree_split->bch_btree_node_alloc->__bch_btree_node_alloc. Fix it by initialize return value in __bch_btree_node_alloc before return. Fixes: cafe56359144 ("bcache: A block layer cache") Signed-off-by: Zheng Wang --- drivers/md/bcache/btree.c | 10 ++++++---- drivers/md/bcache/super.c | 2 +- 2 files changed, 7 insertions(+), 5 deletions(-) diff --git a/drivers/md/bcache/btree.c b/drivers/md/bcache/btree.c index 147c493a989a..35346c1d7c3c 100644 --- a/drivers/md/bcache/btree.c +++ b/drivers/md/bcache/btree.c @@ -1090,10 +1090,12 @@ struct btree *__bch_btree_node_alloc(struct cache_set *c, struct btree_op *op, struct btree *parent) { BKEY_PADDED(key) k; - struct btree *b = ERR_PTR(-EAGAIN); + struct btree *b; mutex_lock(&c->bucket_lock); retry: + /* return ERR_PTR(-EAGAIN) when it fails */ + b = ERR_PTR(-EAGAIN); if (__bch_bucket_alloc_set(c, RESERVE_BTREE, &k.key, wait)) goto err; @@ -1138,7 +1140,7 @@ static struct btree *btree_node_alloc_replacement(struct btree *b, { struct btree *n = bch_btree_node_alloc(b->c, op, b->level, b->parent); - if (!IS_ERR_OR_NULL(n)) { + if (!IS_ERR(n)) { mutex_lock(&n->write_lock); bch_btree_sort_into(&b->keys, &n->keys, &b->c->sort); bkey_copy_key(&n->key, &b->key); @@ -1352,7 +1354,7 @@ static int btree_gc_coalesce(struct btree *b, struct btree_op *op, for (i = 0; i < nodes; i++) { new_nodes[i] = btree_node_alloc_replacement(r[i].b, NULL); - if (IS_ERR_OR_NULL(new_nodes[i])) + if (IS_ERR(new_nodes[i])) goto out_nocoalesce; } @@ -1669,7 +1671,7 @@ static int bch_btree_gc_root(struct btree *b, struct btree_op *op, if (should_rewrite) { n = btree_node_alloc_replacement(b, NULL); - if (!IS_ERR_OR_NULL(n)) { + if (!IS_ERR(n)) { bch_btree_node_write_sync(n); bch_btree_set_root(n); diff --git a/drivers/md/bcache/super.c b/drivers/md/bcache/super.c index ba3909bb6bea..92de714fe75e 100644 --- a/drivers/md/bcache/super.c +++ b/drivers/md/bcache/super.c @@ -2088,7 +2088,7 @@ static int run_cache_set(struct cache_set *c) err = "cannot allocate new btree root"; c->root = __bch_btree_node_alloc(c, NULL, 0, true, NULL); - if (IS_ERR_OR_NULL(c->root)) + if (IS_ERR(c->root)) goto err; mutex_lock(&c->root->write_lock);