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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 26664C6FA82 for ; Mon, 12 Sep 2022 04:58:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229789AbiILE6f (ORCPT ); Mon, 12 Sep 2022 00:58:35 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54924 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229544AbiILE5F (ORCPT ); Mon, 12 Sep 2022 00:57:05 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 79A12220E9 for ; Sun, 11 Sep 2022 21:57:03 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id CC55AB80B9F for ; Mon, 12 Sep 2022 04:57:01 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 70427C433C1; Mon, 12 Sep 2022 04:57:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1662958620; bh=OCV2hiQveIkapoKS6h9F92z6/SFuPA5AbugOZbU4Bl8=; h=Date:To:From:Subject:From; b=S1tGcJUTy6Ka4N2c0FAuxaAX24Y1heDdoYFHj5DCHbk2PIHlsDu7MTA8Jx0W9nT/F i4slC3IVLMn16vBu5qZrYbAX2iu3YraeoRhErU3CqWV5rE/rscwtBwnTyZvO4a/y6R QQaE/WQXASxhEtGIand/Tc+i90hSQ3QT2EPmARgU= Date: Sun, 11 Sep 2022 21:56:59 -0700 To: mm-commits@vger.kernel.org, syzkaller-bugs@googlegroups.com, dan.carpenter@oracle.com, chenxiaosong2@huawei.com, anton@tuxera.com, yin31149@gmail.com, akpm@linux-foundation.org From: Andrew Morton Subject: [merged mm-nonmm-stable] ntfs-fix-out-of-bounds-read-in-ntfs_attr_find.patch removed from -mm tree Message-Id: <20220912045700.70427C433C1@smtp.kernel.org> Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org The quilt patch titled Subject: ntfs: fix out-of-bounds read in ntfs_attr_find() has been removed from the -mm tree. Its filename was ntfs-fix-out-of-bounds-read-in-ntfs_attr_find.patch This patch was dropped because it was merged into the mm-nonmm-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm ------------------------------------------------------ From: Hawkins Jiawei Subject: ntfs: fix out-of-bounds read in ntfs_attr_find() Date: Thu, 1 Sep 2022 00:09:36 +0800 Kernel iterates over ATTR_RECORDs in mft record in ntfs_attr_find(). To ensure access on these ATTR_RECORDs are within bounds, kernel will do some checking during iteration. The problem is that during checking whether ATTR_RECORD's name is within bounds, kernel will dereferences the ATTR_RECORD name_offset field, before checking this ATTR_RECORD strcture is within bounds. This problem may result out-of-bounds read in ntfs_attr_find(), reported by Syzkaller: ================================================================== BUG: KASAN: use-after-free in ntfs_attr_find+0xc02/0xce0 fs/ntfs/attrib.c:597 Read of size 2 at addr ffff88807e352009 by task syz-executor153/3607 [...] Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:317 [inline] print_report.cold+0x2ba/0x719 mm/kasan/report.c:433 kasan_report+0xb1/0x1e0 mm/kasan/report.c:495 ntfs_attr_find+0xc02/0xce0 fs/ntfs/attrib.c:597 ntfs_attr_lookup+0x1056/0x2070 fs/ntfs/attrib.c:1193 ntfs_read_inode_mount+0x89a/0x2580 fs/ntfs/inode.c:1845 ntfs_fill_super+0x1799/0x9320 fs/ntfs/super.c:2854 mount_bdev+0x34d/0x410 fs/super.c:1400 legacy_get_tree+0x105/0x220 fs/fs_context.c:610 vfs_get_tree+0x89/0x2f0 fs/super.c:1530 do_new_mount fs/namespace.c:3040 [inline] path_mount+0x1326/0x1e20 fs/namespace.c:3370 do_mount fs/namespace.c:3383 [inline] __do_sys_mount fs/namespace.c:3591 [inline] __se_sys_mount fs/namespace.c:3568 [inline] __x64_sys_mount+0x27f/0x300 fs/namespace.c:3568 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd [...] The buggy address belongs to the physical page: page:ffffea0001f8d400 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x7e350 head:ffffea0001f8d400 order:3 compound_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 0000000000000000 dead000000000122 ffff888011842140 raw: 0000000000000000 0000000000040004 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88807e351f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88807e351f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff88807e352000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88807e352080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88807e352100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== This patch solves it by moving the ATTR_RECORD strcture's bounds checking earlier, then checking whether ATTR_RECORD's name is within bounds. What's more, this patch also add some comments to improve its maintainability. Link: https://lkml.kernel.org/r/20220831160935.3409-3-yin31149@gmail.com Link: https://lore.kernel.org/all/1636796c-c85e-7f47-e96f-e074fee3c7d3@huawei.com/ Link: https://groups.google.com/g/syzkaller-bugs/c/t_XdeKPGTR4/m/LECAuIGcBgAJ Signed-off-by: chenxiaosong (A) Signed-off-by: Dan Carpenter Signed-off-by: Hawkins Jiawei Reported-by: syzbot+5f8dcabe4a3b2c51c607@syzkaller.appspotmail.com Tested-by: syzbot+5f8dcabe4a3b2c51c607@syzkaller.appspotmail.com Cc: Anton Altaparmakov Cc: syzkaller-bugs Signed-off-by: Andrew Morton --- fs/ntfs/attrib.c | 20 ++++++++++++++++---- 1 file changed, 16 insertions(+), 4 deletions(-) --- a/fs/ntfs/attrib.c~ntfs-fix-out-of-bounds-read-in-ntfs_attr_find +++ a/fs/ntfs/attrib.c @@ -594,11 +594,23 @@ static int ntfs_attr_find(const ATTR_TYP for (;; a = (ATTR_RECORD*)((u8*)a + le32_to_cpu(a->length))) { u8 *mrec_end = (u8 *)ctx->mrec + le32_to_cpu(ctx->mrec->bytes_allocated); - u8 *name_end = (u8 *)a + le16_to_cpu(a->name_offset) + - a->name_length * sizeof(ntfschar); - if ((u8*)a < (u8*)ctx->mrec || (u8*)a > mrec_end || - name_end > mrec_end) + u8 *name_end; + + /* check whether ATTR_RECORD wrap */ + if ((u8 *)a < (u8 *)ctx->mrec) break; + + /* check whether Attribute Record Header is within bounds */ + if ((u8 *)a > mrec_end || + (u8 *)a + sizeof(ATTR_RECORD) > mrec_end) + break; + + /* check whether ATTR_RECORD's name is within bounds */ + name_end = (u8 *)a + le16_to_cpu(a->name_offset) + + a->name_length * sizeof(ntfschar); + if (name_end > mrec_end) + break; + ctx->attr = a; if (unlikely(le32_to_cpu(a->type) > le32_to_cpu(type) || a->type == AT_END)) _ Patches currently in -mm which might be from yin31149@gmail.com are