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 X-Spam-Level: X-Spam-Status: No, score=-8.5 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 00979C433E7 for ; Fri, 9 Oct 2020 01:30:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9117D22242 for ; Fri, 9 Oct 2020 01:30:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730379AbgJIBaU (ORCPT ); Thu, 8 Oct 2020 21:30:20 -0400 Received: from szxga06-in.huawei.com ([45.249.212.32]:39218 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1725979AbgJIBaU (ORCPT ); Thu, 8 Oct 2020 21:30:20 -0400 Received: from DGGEMS406-HUB.china.huawei.com (unknown [172.30.72.59]) by Forcepoint Email with ESMTP id 15DA58DAC5AD0225ECCE; Fri, 9 Oct 2020 09:30:18 +0800 (CST) Received: from [10.136.114.67] (10.136.114.67) by smtp.huawei.com (10.3.19.206) with Microsoft SMTP Server (TLS) id 14.3.487.0; Fri, 9 Oct 2020 09:30:15 +0800 Subject: Re: [PATCH] f2fs: reject CASEFOLD inode flag without casefold feature To: Eric Biggers , Jaegeuk Kim , "Chao Yu" , CC: Daniel Rosenberg , Gabriel Krisman Bertazi , , , , References: <00000000000085be6f05b12a1366@google.com> <20201008191522.1948889-1-ebiggers@kernel.org> From: Chao Yu Message-ID: Date: Fri, 9 Oct 2020 09:30:15 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 MIME-Version: 1.0 In-Reply-To: <20201008191522.1948889-1-ebiggers@kernel.org> Content-Type: text/plain; charset="windows-1252"; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [10.136.114.67] X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2020/10/9 3:15, Eric Biggers wrote: > From: Eric Biggers > > syzbot reported: > > general protection fault, probably for non-canonical address 0xdffffc0000000001: 0000 [#1] PREEMPT SMP KASAN > KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f] > CPU: 0 PID: 6860 Comm: syz-executor835 Not tainted 5.9.0-rc8-syzkaller #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 > RIP: 0010:utf8_casefold+0x43/0x1b0 fs/unicode/utf8-core.c:107 > [...] > Call Trace: > f2fs_init_casefolded_name fs/f2fs/dir.c:85 [inline] > __f2fs_setup_filename fs/f2fs/dir.c:118 [inline] > f2fs_prepare_lookup+0x3bf/0x640 fs/f2fs/dir.c:163 > f2fs_lookup+0x10d/0x920 fs/f2fs/namei.c:494 > __lookup_hash+0x115/0x240 fs/namei.c:1445 > filename_create+0x14b/0x630 fs/namei.c:3467 > user_path_create fs/namei.c:3524 [inline] > do_mkdirat+0x56/0x310 fs/namei.c:3664 > do_syscall_64+0x31/0x70 arch/x86/entry/common.c:46 > entry_SYSCALL_64_after_hwframe+0x44/0xa9 > [...] > > The problem is that an inode has F2FS_CASEFOLD_FL set, but the > filesystem doesn't have the casefold feature flag set, and therefore > super_block::s_encoding is NULL. > > Fix this by making sanity_check_inode() reject inodes that have > F2FS_CASEFOLD_FL when the filesystem doesn't have the casefold feature. > > Reported-by: syzbot+05139c4039d0679e19ff@syzkaller.appspotmail.com > Fixes: 2c2eb7a300cd ("f2fs: Support case-insensitive file name lookups") > Signed-off-by: Eric Biggers Reviewed-by: Chao Yu Thanks,