From nobody Sat Apr 11 12:31:25 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 22870C4332F for ; Tue, 8 Nov 2022 01:39:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233368AbiKHBjp (ORCPT ); Mon, 7 Nov 2022 20:39:45 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34628 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229534AbiKHBjn (ORCPT ); Mon, 7 Nov 2022 20:39:43 -0500 Received: from szxga02-in.huawei.com (szxga02-in.huawei.com [45.249.212.188]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0E557186FF for ; Mon, 7 Nov 2022 17:39:42 -0800 (PST) Received: from dggpemm500022.china.huawei.com (unknown [172.30.72.55]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4N5rPK0LYHzRp63; Tue, 8 Nov 2022 09:39:33 +0800 (CST) Received: from dggpemm100009.china.huawei.com (7.185.36.113) by dggpemm500022.china.huawei.com (7.185.36.162) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.31; Tue, 8 Nov 2022 09:39:40 +0800 Received: from huawei.com (10.175.113.32) by dggpemm100009.china.huawei.com (7.185.36.113) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.31; Tue, 8 Nov 2022 09:39:39 +0800 From: Liu Shixin To: Jan Kara CC: , Liu Shixin Subject: [PATCH] udf: fix NULL pointer dereference in udf_rename() Date: Tue, 8 Nov 2022 10:27:41 +0800 Message-ID: <20221108022741.492573-1-liushixin2@huawei.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Originating-IP: [10.175.113.32] X-ClientProxiedBy: dggems703-chm.china.huawei.com (10.3.19.180) To dggpemm100009.china.huawei.com (7.185.36.113) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" Syzbot reported a NULL pointer dereference: Unable to handle kernel NULL pointer dereference at virtual address 000000= 0000000020 [...] Call trace: __memset+0x84/0x188 arch/arm64/lib/memset.S:98 udf_delete_entry fs/udf/namei.c:577 [inline] udf_rename+0x47c/0x6d0 fs/udf/namei.c:1173 vfs_rename+0x59c/0x7f8 fs/namei.c:4756 do_renameat2+0x490/0x758 fs/namei.c:4907 __do_sys_renameat2 fs/namei.c:4940 [inline] [...] Fix this by check return value of udf_find_entry() since ofi may be NULL or error code. Reported-by: syzbot+17fcf98a689ff64f669b@syzkaller.appspotmail.com Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Liu Shixin --- fs/udf/namei.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/fs/udf/namei.c b/fs/udf/namei.c index fb4c30e05245..e0267e72cebb 100644 --- a/fs/udf/namei.c +++ b/fs/udf/namei.c @@ -1170,6 +1170,11 @@ static int udf_rename(struct user_namespace *mnt_use= rns, struct inode *old_dir, =20 /* The old fid may have moved - find it again */ ofi =3D udf_find_entry(old_dir, &old_dentry->d_name, &ofibh, &ocfi); + if (IS_ERR_OR_NULL(ofi)) { + retval =3D PTR_ERR(ofi); + goto end_rename; + } + udf_delete_entry(old_dir, ofi, &ofibh, &ocfi); =20 if (new_inode) { --=20 2.25.1