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 77ABDC433EF for ; Sat, 9 Jul 2022 00:58:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229503AbiGIAzc (ORCPT ); Fri, 8 Jul 2022 20:55:32 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51812 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229491AbiGIAzb (ORCPT ); Fri, 8 Jul 2022 20:55:31 -0400 Received: from mail-pj1-x102d.google.com (mail-pj1-x102d.google.com [IPv6:2607:f8b0:4864:20::102d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 16E65691EB for ; Fri, 8 Jul 2022 17:55:29 -0700 (PDT) Received: by mail-pj1-x102d.google.com with SMTP id q5-20020a17090a304500b001efcc885cc4so164071pjl.4 for ; Fri, 08 Jul 2022 17:55:29 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=5tfoXTTrku/dQJy1oFSssPrlHXbJM14k7EhQ5B1YVWk=; b=RFZ/9uNlT+kbKB+KcbIS08mBkVVSXOnVZkTk2JLCBDJCF8QLX+EnxUJ7RtKaN1um+n TedWU8xcqGINBOAJd4IaUMQ4ft7TgD+ZRRX7TKyxcvWImnmXvNrpoYMcT+0uFlkmMvFm v4X2hB2ZP75HgYmHGThxq1r0MMQgTtACrxDW1arL8xmOVJYvAyzz9Hlm5vil7sq59ih9 It7zX4nW/Exd9JhuFX8+NQxuFrtADvy255NN2Opg/T/7H9Tdf0Jj1W530sU55R9JhIfZ vGsDU7lVfwM8byerNxhh5njyVOCwR8TKQmpkgrsB8GiQzDKp18KAmVHCCopqnNTRn0A7 8zzA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=5tfoXTTrku/dQJy1oFSssPrlHXbJM14k7EhQ5B1YVWk=; b=IEgbNC0xb/B8RVBF2LXS4Z7Nl6ONBRIHOOAAikYeiXkgGXGlJgvDWfknmOlEVZ0x5L OKqy49Rh+ZpOWohp+cCU0Ra3GrHcLCJMziv8AubwVyz4vXV7i0OtT4Pt4xBWJor+W5vB 6SmbHvd4cM0itivpQ2c+d/bI6E+U8IxrFhtgQNjjPTafsceYQlSrALoy4PzKbjg1dLXA 8gG0Hnn76wjDgA9BhP12RwlZKdLLTc4MHaFBS+k0UfpTQyW7yGD/CYxuIyJvQcAkm67O zQS16h1OvTmZCMazmP7M7uagfCmMGcfdvZEEzRAnliZzaBWj1UwNtnSR9WXGNVNDeiCx 7xnQ== X-Gm-Message-State: AJIora8znvnr5bBrccGvpDRMrY02VLVHOSYP/5vUjXeqxTQILWrvQtV5 jSzti7pTwW8l6qn2RNkTFmA= X-Google-Smtp-Source: AGRyM1uEGMgEeHvZ7/1r1lHZfwXyQnGYSx1n4aEw+xWLRHCwPwOJvo7eLXnlY8Hkr62r/X/jaeMZOg== X-Received: by 2002:a17:902:e542:b0:16b:fcbe:7b90 with SMTP id n2-20020a170902e54200b0016bfcbe7b90mr6384914plf.90.1657328128595; Fri, 08 Jul 2022 17:55:28 -0700 (PDT) Received: from ubuntu.lan (pcd568068.netvigator.com. [218.102.100.68]) by smtp.gmail.com with ESMTPSA id c5-20020a170902c2c500b0016beea47800sm152394pla.41.2022.07.08.17.55.19 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 08 Jul 2022 17:55:28 -0700 (PDT) From: Hawkins Jiawei To: chenxiaosong2@huawei.com Cc: akpm@linux-foundation.org, anton@tuxera.com, linux-kernel@vger.kernel.org, linux-ntfs-dev@lists.sourceforge.net, liuyongqiang13@huawei.com, yi.zhang@huawei.com, zhangxiaoxu5@huawei.com, 18801353760@163.com, skhan@linuxfoundation.org, paskripkin@gmail.com, linux-kernel-mentees@lists.linuxfoundation.org Subject: Re: [PATCH v2] ntfs: fix use-after-free in ntfs_ucsncmp() Date: Sat, 9 Jul 2022 08:54:51 +0800 Message-Id: <20220709005450.2220-1-yin31149@gmail.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220707105329.4020708-1-chenxiaosong2@huawei.com> References: <20220707105329.4020708-1-chenxiaosong2@huawei.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > Fix this by adding sanity check on end address of attibute name string. > diff --git a/fs/ntfs/attrib.c b/fs/ntfs/attrib.c > index 4de597a83b88..9ab8766872d2 100644 > --- a/fs/ntfs/attrib.c > +++ b/fs/ntfs/attrib.c > @@ -592,8 +592,12 @@ static int ntfs_attr_find(const ATTR_TYPE type, const ntfschar *name, > a = (ATTR_RECORD*)((u8*)ctx->attr + > le32_to_cpu(ctx->attr->length)); > for (;; a = (ATTR_RECORD*)((u8*)a + le32_to_cpu(a->length))) { > - if ((u8*)a < (u8*)ctx->mrec || (u8*)a > (u8*)ctx->mrec + > - le32_to_cpu(ctx->mrec->bytes_allocated)) > + 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; In my opinion, name_length field just means the number of characters, yet each character is a ntfschar type. So name should be name_length * sizeof(ntfschar) bytes. The example is at https://elixir.bootlin.com/linux/v5.19-rc5/source/fs/ntfs/attrib.c#L1667 > + if ((u8*)a < (u8*)ctx->mrec || (u8*)a > mrec_end || > + name_end > mrec_end) > break; > ctx->attr = a; > if (unlikely(le32_to_cpu(a->type) > le32_to_cpu(type) || > --