From nobody Wed Apr 8 04:58:31 2026 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 5EB01C04A95 for ; Sat, 22 Oct 2022 11:21:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230429AbiJVLVZ (ORCPT ); Sat, 22 Oct 2022 07:21:25 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38104 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230346AbiJVLU6 (ORCPT ); Sat, 22 Oct 2022 07:20:58 -0400 Received: from szxga03-in.huawei.com (szxga03-in.huawei.com [45.249.212.189]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8E347EA9C8 for ; Sat, 22 Oct 2022 03:48:59 -0700 (PDT) Received: from kwepemi500012.china.huawei.com (unknown [172.30.72.55]) by szxga03-in.huawei.com (SkyGuard) with ESMTP id 4MvdKz0PMgzJn3b; Sat, 22 Oct 2022 18:46:15 +0800 (CST) Received: from huawei.com (10.175.101.6) by kwepemi500012.china.huawei.com (7.221.188.12) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.31; Sat, 22 Oct 2022 18:48:56 +0800 From: Li Zetao To: , , CC: , , , , Subject: [PATCH] ubifs: Fix memory leak in alloc_wbufs() Date: Sat, 22 Oct 2022 19:52:11 +0800 Message-ID: <20221022115211.1969429-1-lizetao1@huawei.com> X-Mailer: git-send-email 2.31.1 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Originating-IP: [10.175.101.6] X-ClientProxiedBy: dggems704-chm.china.huawei.com (10.3.19.181) To kwepemi500012.china.huawei.com (7.221.188.12) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" kmemleak reported a sequence of memory leaks, and show them as following: unreferenced object 0xffff8881575f8400 (size 1024): comm "mount", pid 19625, jiffies 4297119604 (age 20.383s) hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace: [] __kmalloc+0x4d/0x150 [] ubifs_mount+0x307b/0x7170 [ubifs] [] legacy_get_tree+0xed/0x1d0 [] vfs_get_tree+0x7d/0x230 [] path_mount+0xdd4/0x17b0 [] __x64_sys_mount+0x1fa/0x270 [] do_syscall_64+0x35/0x80 [] entry_SYSCALL_64_after_hwframe+0x46/0xb0 unreferenced object 0xffff8881798a6e00 (size 512): comm "mount", pid 19677, jiffies 4297121912 (age 37.816s) hex dump (first 32 bytes): 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk backtrace: [] __kmalloc+0x4d/0x150 [] ubifs_wbuf_init+0x52/0x480 [ubifs] [] ubifs_mount+0x31f5/0x7170 [ubifs] [] legacy_get_tree+0xed/0x1d0 [] vfs_get_tree+0x7d/0x230 [] path_mount+0xdd4/0x17b0 [] __x64_sys_mount+0x1fa/0x270 [] do_syscall_64+0x35/0x80 [] entry_SYSCALL_64_after_hwframe+0x46/0xb0 The problem is that the ubifs_wbuf_init() returns an error in the loop which in the alloc_wbufs(), then the wbuf->buf and wbuf->inodes that were successfully alloced before are not freed. Fix it by adding error hanging path in alloc_wbufs() which frees the memory alloced before when ubifs_wbuf_init() returns an error. Fixes: 1e51764a3c2a ("UBIFS: add new flash file system") Signed-off-by: Li Zetao Reviewed-by: Zhihao Cheng --- fs/ubifs/super.c | 17 +++++++++++++---- 1 file changed, 13 insertions(+), 4 deletions(-) diff --git a/fs/ubifs/super.c b/fs/ubifs/super.c index d0c9a09988bc..32cb14759796 100644 --- a/fs/ubifs/super.c +++ b/fs/ubifs/super.c @@ -833,7 +833,7 @@ static int alloc_wbufs(struct ubifs_info *c) INIT_LIST_HEAD(&c->jheads[i].buds_list); err =3D ubifs_wbuf_init(c, &c->jheads[i].wbuf); if (err) - return err; + goto out_wbuf; =20 c->jheads[i].wbuf.sync_callback =3D &bud_wbuf_callback; c->jheads[i].wbuf.jhead =3D i; @@ -841,7 +841,7 @@ static int alloc_wbufs(struct ubifs_info *c) c->jheads[i].log_hash =3D ubifs_hash_get_desc(c); if (IS_ERR(c->jheads[i].log_hash)) { err =3D PTR_ERR(c->jheads[i].log_hash); - goto out; + goto out_log_hash; } } =20 @@ -854,9 +854,18 @@ static int alloc_wbufs(struct ubifs_info *c) =20 return 0; =20 -out: - while (i--) +out_log_hash: + kfree(c->jheads[i].wbuf.buf); + kfree(c->jheads[i].wbuf.inodes); + +out_wbuf: + while (i--) { + kfree(c->jheads[i].wbuf.buf); + kfree(c->jheads[i].wbuf.inodes); kfree(c->jheads[i].log_hash); + } + kfree(c->jheads); + c->jheads =3D NULL; =20 return err; } --=20 2.31.1