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[23.128.96.18]) by mx.google.com with ESMTP id e2si1462202edm.608.2021.09.11.00.42.37; Sat, 11 Sep 2021 00:43:24 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=huawei.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235370AbhIKHlD (ORCPT + 99 others); Sat, 11 Sep 2021 03:41:03 -0400 Received: from szxga02-in.huawei.com ([45.249.212.188]:9417 "EHLO szxga02-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233040AbhIKHlC (ORCPT ); Sat, 11 Sep 2021 03:41:02 -0400 Received: from dggemv704-chm.china.huawei.com (unknown [172.30.72.55]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4H64K90RnGz8xZP; Sat, 11 Sep 2021 15:35:25 +0800 (CST) Received: from dggpeml500019.china.huawei.com (7.185.36.137) by dggemv704-chm.china.huawei.com (10.3.19.47) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.8; Sat, 11 Sep 2021 15:39:48 +0800 Received: from huawei.com (10.175.124.27) by dggpeml500019.china.huawei.com (7.185.36.137) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.8; Sat, 11 Sep 2021 15:39:47 +0800 From: Wu Bo To: , CC: , , , Subject: [PATCH] bcache: Fix memory leak when cache_alloc() return failed Date: Sat, 11 Sep 2021 16:08:54 +0800 Message-ID: <1631347734-9950-1-git-send-email-wubo40@huawei.com> X-Mailer: git-send-email 1.8.3.1 MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.175.124.27] X-ClientProxiedBy: dggems704-chm.china.huawei.com (10.3.19.181) To dggpeml500019.china.huawei.com (7.185.36.137) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Wu Bo If cache_alloc() get error when register a cache device, the ca->kobj is not initialized, the bch_cache_release() no chance to be called. So "ca" object will not be released. In addition, if register_cache_set() return failed when register a cache device, kobject_put(&ca->kobj) will be called and "ca" objects will be released in bch_cache_release() function. But pr_notice() called after kobject_put(&ca->kobj), the "ca->cache_dev_name" access memory that has been freed. Signed-off-by: Wu Bo --- drivers/md/bcache/super.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/drivers/md/bcache/super.c b/drivers/md/bcache/super.c index f2874c7..30569f4 100644 --- a/drivers/md/bcache/super.c +++ b/drivers/md/bcache/super.c @@ -2366,13 +2366,17 @@ static int register_cache(struct cache_sb *sb, struct cache_sb_disk *sb_disk, * explicitly call blkdev_put() here. */ blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL); + if (ca->sb_disk) + put_page(virt_to_page(ca->sb_disk)); if (ret == -ENOMEM) err = "cache_alloc(): -ENOMEM"; else if (ret == -EPERM) err = "cache_alloc(): cache device is too small"; else err = "cache_alloc(): unknown error"; - goto err; + pr_notice("error %s: %s\n", ca->cache_dev_name, err); + kfree(ca); + return ret; } if (kobject_add(&ca->kobj, bdev_kobj(bdev), "bcache")) { @@ -2393,11 +2397,9 @@ static int register_cache(struct cache_sb *sb, struct cache_sb_disk *sb_disk, pr_info("registered cache device %s\n", ca->cache_dev_name); out: - kobject_put(&ca->kobj); - -err: if (err) pr_notice("error %s: %s\n", ca->cache_dev_name, err); + kobject_put(&ca->kobj); return ret; } -- 1.8.3.1