From patchwork Fri Sep 6 05:16:16 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Michael Tokarev X-Patchwork-Id: 13793276 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 lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id D22C5C54FC6 for ; Fri, 6 Sep 2024 05:22:16 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1smRNg-0007OL-Bz; Fri, 06 Sep 2024 01:19:36 -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 1smRNK-00054J-HC; Fri, 06 Sep 2024 01:19:15 -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 1smRNA-0008E6-GE; Fri, 06 Sep 2024 01:19:12 -0400 Received: from tsrv.corpit.ru (tsrv.tls.msk.ru [192.168.177.2]) by isrv.corpit.ru (Postfix) with ESMTP id E871A8C131; Fri, 6 Sep 2024 08:15:17 +0300 (MSK) Received: from tls.msk.ru (mjt.wg.tls.msk.ru [192.168.177.130]) by tsrv.corpit.ru (Postfix) with SMTP id 98EB4133376; Fri, 6 Sep 2024 08:16:35 +0300 (MSK) Received: (nullmailer pid 10470 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 28/40] vvfat: Fix wrong checks for cluster mappings invariant Date: Fri, 6 Sep 2024 08:16:16 +0300 Message-Id: <20240906051633.10288-28-mjt@tls.msk.ru> X-Mailer: git-send-email 2.39.2 In-Reply-To: References: MIME-Version: 1.0 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+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org From: Amjad Alsharafi How this `abort` was intended to check for was: - if the `mapping->first_mapping_index` is not the same as `first_mapping_index`, which **should** happen only in one case, when we are handling the first mapping, in that case `mapping->first_mapping_index == -1`, in all other cases, the other mappings after the first should have the condition `true`. - From above, we know that this is the first mapping, so if the offset is not `0`, then abort, since this is an invalid state. The issue was that `first_mapping_index` is not set if we are checking from the middle, the variable `first_mapping_index` is only set if we passed through the check `cluster_was_modified` with the first mapping, and in the same function call we checked the other mappings. One approach is to go into the loop even if `cluster_was_modified` is not true so that we will be able to set `first_mapping_index` for the first mapping, but since `first_mapping_index` is only used here, another approach is to just check manually for the `mapping->first_mapping_index != -1` since we know that this is the value for the only entry where `offset == 0` (i.e. first mapping). Signed-off-by: Amjad Alsharafi Reviewed-by: Kevin Wolf Message-ID: Signed-off-by: Kevin Wolf (cherry picked from commit f60a6f7e17bf2a2a0f0a08265ac9b077fce42858) Signed-off-by: Michael Tokarev diff --git a/block/vvfat.c b/block/vvfat.c index 3a83ab5af4..1adcc6040f 100644 --- a/block/vvfat.c +++ b/block/vvfat.c @@ -1879,7 +1879,6 @@ static uint32_t get_cluster_count_for_direntry(BDRVVVFATState* s, uint32_t cluster_num = begin_of_direntry(direntry); uint32_t offset = 0; - int first_mapping_index = -1; mapping_t* mapping = NULL; const char* basename2 = NULL; @@ -1941,14 +1940,9 @@ static uint32_t get_cluster_count_for_direntry(BDRVVVFATState* s, if (strcmp(basename, basename2)) copy_it = 1; - first_mapping_index = array_index(&(s->mapping), mapping); - } - - if (mapping->first_mapping_index != first_mapping_index - && mapping->info.file.offset > 0) { - abort(); - copy_it = 1; } + assert(mapping->first_mapping_index == -1 + || mapping->info.file.offset > 0); /* need to write out? */ if (!was_modified && is_file(direntry)) {