From patchwork Fri Jul 3 09:21:41 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kevin Wolf X-Patchwork-Id: 278703 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=-7.1 required=3.0 tests=DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS 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 EF1FCC433E0 for ; Fri, 3 Jul 2020 09:24:25 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id BD2A220723 for ; Fri, 3 Jul 2020 09:24:25 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="bbNsrPgZ" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org BD2A220723 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:54486 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jrHvl-0007V9-1f for qemu-devel@archiver.kernel.org; Fri, 03 Jul 2020 05:24:25 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:35984) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jrHtV-0002pH-TF for qemu-devel@nongnu.org; Fri, 03 Jul 2020 05:22:05 -0400 Received: from us-smtp-2.mimecast.com ([205.139.110.61]:38910 helo=us-smtp-delivery-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1jrHtU-0000yJ-0i for qemu-devel@nongnu.org; Fri, 03 Jul 2020 05:22:05 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1593768120; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=TVF5KUpHWkY3Qg0PDkkb2MQ94k7vQg1CYbztYqZ3E/s=; b=bbNsrPgZry0pKwnEnauxzeu0bOgh2iqDFtH8VXq4mA5rKEskTDQ/FQXq3yMoq7sVbQwfeJ m4bHGwTrNKfWrrVZesoYIfa7XwEYGV+otiERZju4pkOTmQpibMJwcgajK8HUgP/VMJgirW /9po8Z4j9Trfk2sfp3MPwRg3UwM5VrE= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-78-SiLobQuyMleMxuVHlRWzmQ-1; Fri, 03 Jul 2020 05:21:58 -0400 X-MC-Unique: SiLobQuyMleMxuVHlRWzmQ-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 9FA5F107ACCA; Fri, 3 Jul 2020 09:21:57 +0000 (UTC) Received: from linux.fritz.box.com (ovpn-114-90.ams2.redhat.com [10.36.114.90]) by smtp.corp.redhat.com (Postfix) with ESMTP id AD86A7AC63; Fri, 3 Jul 2020 09:21:56 +0000 (UTC) From: Kevin Wolf To: qemu-block@nongnu.org Subject: [PULL 5/7] vvfat: Fix array_remove_slice() Date: Fri, 3 Jul 2020 11:21:41 +0200 Message-Id: <20200703092143.165594-6-kwolf@redhat.com> In-Reply-To: <20200703092143.165594-1-kwolf@redhat.com> References: <20200703092143.165594-1-kwolf@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=kwolf@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Received-SPF: pass client-ip=205.139.110.61; envelope-from=kwolf@redhat.com; helo=us-smtp-delivery-1.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/07/03 03:17:33 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] X-Spam_score_int: -30 X-Spam_score: -3.1 X-Spam_bar: --- X-Spam_report: (-3.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-1, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H3=-0.01, RCVD_IN_MSPIKE_WL=-0.01, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=_AUTOLEARN X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: kwolf@redhat.com, peter.maydell@linaro.org, qemu-devel@nongnu.org Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" array_remove_slice() calls array_roll() with array->next - 1 as the destination index. This is only correct for count == 1, otherwise we're writing past the end of the array. array->next - count would be correct. However, this is the only place ever calling array_roll(), so this rather complicated operation isn't even necessary. Fix the problem and simplify the code by replacing it with a single memmove() call. array_roll() can now be removed. Reported-by: Nathan Huckleberry Signed-off-by: Kevin Wolf Message-Id: <20200623175534.38286-3-kwolf@redhat.com> Reviewed-by: Eric Blake Signed-off-by: Kevin Wolf --- block/vvfat.c | 42 +++++------------------------------------- 1 file changed, 5 insertions(+), 37 deletions(-) diff --git a/block/vvfat.c b/block/vvfat.c index 62230542e5..2eb8cbb19f 100644 --- a/block/vvfat.c +++ b/block/vvfat.c @@ -140,48 +140,16 @@ static inline void* array_insert(array_t* array,unsigned int index,unsigned int return array->pointer+index*array->item_size; } -/* this performs a "roll", so that the element which was at index_from becomes - * index_to, but the order of all other elements is preserved. */ -static inline int array_roll(array_t* array,int index_to,int index_from,int count) -{ - char* buf; - char* from; - char* to; - int is; - - if(!array || - index_to<0 || index_to>=array->next || - index_from<0 || index_from>=array->next) - return -1; - - if(index_to==index_from) - return 0; - - is=array->item_size; - from=array->pointer+index_from*is; - to=array->pointer+index_to*is; - buf=g_malloc(is*count); - memcpy(buf,from,is*count); - - if(index_to=0); assert(count > 0); assert(index + count <= array->next); - if(array_roll(array,array->next-1,index,count)) - return -1; + + memmove(array->pointer + index * array->item_size, + array->pointer + (index + count) * array->item_size, + (array->next - index - count) * array->item_size); + array->next -= count; return 0; }