From nobody Sun Nov 24 07:39:13 2024 Delivered-To: importer@patchew.org Authentication-Results: mx.zohomail.com; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1725600382392445.6051904673336; Thu, 5 Sep 2024 22:26:22 -0700 (PDT) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1smRNc-0006nR-Uk; Fri, 06 Sep 2024 01:19:33 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1smRND-0004VL-Nb; Fri, 06 Sep 2024 01:19:09 -0400 Received: from isrv.corpit.ru ([86.62.121.231]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1smRNB-0008GX-OS; Fri, 06 Sep 2024 01:19:07 -0400 Received: from tsrv.corpit.ru (tsrv.tls.msk.ru [192.168.177.2]) by isrv.corpit.ru (Postfix) with ESMTP id 01FCE8C132; Fri, 6 Sep 2024 08:15:18 +0300 (MSK) Received: from tls.msk.ru (mjt.wg.tls.msk.ru [192.168.177.130]) by tsrv.corpit.ru (Postfix) with SMTP id A69F7133377; Fri, 6 Sep 2024 08:16:35 +0300 (MSK) Received: (nullmailer pid 10473 invoked by uid 1000); Fri, 06 Sep 2024 05:16:33 -0000 From: Michael Tokarev To: qemu-devel@nongnu.org Cc: qemu-stable@nongnu.org, Amjad Alsharafi , Kevin Wolf , Michael Tokarev Subject: [Stable-7.2.14 29/40] vvfat: Fix reading files with non-continuous clusters Date: Fri, 6 Sep 2024 08:16:17 +0300 Message-Id: <20240906051633.10288-29-mjt@tls.msk.ru> X-Mailer: git-send-email 2.39.2 In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Received-SPF: pass client-ip=86.62.121.231; envelope-from=mjt@tls.msk.ru; helo=isrv.corpit.ru X-Spam_score_int: -68 X-Spam_score: -6.9 X-Spam_bar: ------ X-Spam_report: (-6.9 / 5.0 requ) BAYES_00=-1.9, RCVD_IN_DNSWL_HI=-5, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: qemu-devel-bounces+importer=patchew.org@nongnu.org X-ZM-MESSAGEID: 1725600383681116600 Content-Type: text/plain; charset="utf-8" From: Amjad Alsharafi When reading with `read_cluster` we get the `mapping` with `find_mapping_for_cluster` and then we call `open_file` for this mapping. The issue appear when its the same file, but a second cluster that is not immediately after it, imagine clusters `500 -> 503`, this will give us 2 mappings one has the range `500..501` and another `503..504`, both point to the same file, but different offsets. When we don't open the file since the path is the same, we won't assign `s->current_mapping` and thus accessing way out of bound of the file. From our example above, after `open_file` (that didn't open anything) we will get the offset into the file with `s->cluster_size*(cluster_num-s->current_mapping->begin)`, which will give us `0x2000 * (504-500)`, which is out of bound for this mapping and will produce some issues. Signed-off-by: Amjad Alsharafi Message-ID: <1f3ea115779abab62ba32c788073cdc99f9ad5dd.1721470238.git.amjads= harafi10@gmail.com> [kwolf: Simplified the patch based on Amjad's analysis and input] Signed-off-by: Kevin Wolf (cherry picked from commit 5eed3db336506b529b927ba221fe0d836e5b8819) Signed-off-by: Michael Tokarev diff --git a/block/vvfat.c b/block/vvfat.c index 1adcc6040f..eb844c3134 100644 --- a/block/vvfat.c +++ b/block/vvfat.c @@ -1368,8 +1368,9 @@ static int open_file(BDRVVVFATState* s,mapping_t* map= ping) return -1; vvfat_close_current_file(s); s->current_fd =3D fd; - s->current_mapping =3D mapping; } + + s->current_mapping =3D mapping; return 0; } =20 --=20 2.39.2