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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 16262C41535 for ; Fri, 22 Dec 2023 08:51:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-ID:Date:Subject:CC:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=eTjlXvD/1LLQpUHWoGko0WJV3gYJSqjKGzNzPf6RTUw=; b=PCvfn3TsMK0//J ZPJP9WOD1ZdYvZq6MIzaLBOrFtradl7tynI9uS0QdCxNn5MHtgSIy1kAL5qXItPpk8OLZBZ43RG2x nANcP2Ifcjzm5sm6k7EQiSsyI0rOr6MwTlevBeiZGGtVvzzqddYmKDj1LlyEF8EGYJi9BalD0YiHw CDLtdiBKIJS4RZLT+Qmipf5oRRt490c1dGTTOkfkfy+t01TFms+Gb37j6II+zFPoKUH3zArLK1obl yAWPQou3AEKwIvExv+jEEFMCzhAW6hc8X6SkxsvUUOgS/SmZtVJpd3/YKKe6LvNpwEQY89jg4ip8B obZZqClzPQUqR4RR1lMA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1rGbFx-005MOt-1F; Fri, 22 Dec 2023 08:51:45 +0000 Received: from szxga03-in.huawei.com ([45.249.212.189]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1rGbFu-005MN6-0a for linux-mtd@lists.infradead.org; Fri, 22 Dec 2023 08:51:43 +0000 Received: from mail.maildlp.com (unknown [172.19.162.254]) by szxga03-in.huawei.com (SkyGuard) with ESMTP id 4SxLcd3vTbzMp5H; Fri, 22 Dec 2023 16:51:13 +0800 (CST) Received: from kwepemm000013.china.huawei.com (unknown [7.193.23.81]) by mail.maildlp.com (Postfix) with ESMTPS id B29ED18001A; Fri, 22 Dec 2023 16:51:29 +0800 (CST) Received: from huawei.com (10.175.127.227) by kwepemm000013.china.huawei.com (7.193.23.81) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.35; Fri, 22 Dec 2023 16:51:29 +0800 From: Zhihao Cheng To: , , CC: , Subject: [PATCH v2 2/2] ubifs: ubifs_symlink: Fix memleak of inode->i_link in error path Date: Fri, 22 Dec 2023 16:54:46 +0800 Message-ID: <20231222085446.781838-3-chengzhihao1@huawei.com> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20231222085446.781838-1-chengzhihao1@huawei.com> References: <20231222085446.781838-1-chengzhihao1@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.175.127.227] X-ClientProxiedBy: dggems703-chm.china.huawei.com (10.3.19.180) To kwepemm000013.china.huawei.com (7.193.23.81) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20231222_005142_415922_14F16389 X-CRM114-Status: UNSURE ( 7.98 ) X-CRM114-Notice: Please train this message. X-BeenThere: linux-mtd@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-mtd" Errors-To: linux-mtd-bounces+linux-mtd=archiver.kernel.org@lists.infradead.org For error handling path in ubifs_symlink(), inode will be marked as bad first, then iput() is invoked. If inode->i_link is initialized by fscrypt_encrypt_symlink() in encryption scenario, inode->i_link won't be freed by callchain ubifs_free_inode -> fscrypt_free_inode in error handling path, because make_bad_inode() has changed 'inode->i_mode' as 'S_IFREG'. Following kmemleak is easy to be reproduced by injecting error in ubifs_jnl_update() when doing symlink in encryption scenario: unreferenced object 0xffff888103da3d98 (size 8): comm "ln", pid 1692, jiffies 4294914701 (age 12.045s) backtrace: kmemdup+0x32/0x70 __fscrypt_encrypt_symlink+0xed/0x1c0 ubifs_symlink+0x210/0x300 [ubifs] vfs_symlink+0x216/0x360 do_symlinkat+0x11a/0x190 do_syscall_64+0x3b/0xe0 There are two ways fixing it: 1. Remove make_bad_inode() in error handling path. We can do that because ubifs_evict_inode() will do same processes for good symlink inode and bad symlink inode, for inode->i_nlink checking is before is_bad_inode(). 2. Free inode->i_link before marking inode bad. Method 2 is picked, it has less influence, personally, I think. Cc: stable@vger.kernel.org Fixes: 2c58d548f570 ("fscrypt: cache decrypted symlink target in ->i_link") Signed-off-by: Zhihao Cheng Suggested-by: Eric Biggers --- fs/ubifs/dir.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/fs/ubifs/dir.c b/fs/ubifs/dir.c index 3b13c648d490..e413a9cf8ee3 100644 --- a/fs/ubifs/dir.c +++ b/fs/ubifs/dir.c @@ -1234,6 +1234,8 @@ static int ubifs_symlink(struct mnt_idmap *idmap, struct inode *dir, dir_ui->ui_size = dir->i_size; mutex_unlock(&dir_ui->ui_mutex); out_inode: + /* Free inode->i_link before inode is marked as bad. */ + fscrypt_free_inode(inode); make_bad_inode(inode); iput(inode); out_fname: -- 2.31.1 ______________________________________________________ Linux MTD discussion mailing list http://lists.infradead.org/mailman/listinfo/linux-mtd/