From patchwork Mon Aug 5 21:08:49 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kevin Wolf X-Patchwork-Id: 13754063 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 1BA76C52D6D for ; Mon, 5 Aug 2024 21:10:41 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1sb4xb-0001gI-1D; Mon, 05 Aug 2024 17:09:46 -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 1sb4xR-0001EZ-JJ for qemu-devel@nongnu.org; Mon, 05 Aug 2024 17:09:34 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1sb4xP-00005m-Up for qemu-devel@nongnu.org; Mon, 05 Aug 2024 17:09:33 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1722892170; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=/Qu6i6/DIWfHhjmc4NvZgMJ7eTASrEHvQhpohLIlIPw=; b=VQvR9b8XNFAa9/dNzjdDVgEyjQYYMzrvU/1g33QbNdo5xwJjoRk0nfKUHl7U3BZZWeNbwo rWHyI2v5kxm9frlYSyF4Xll7jCdi9u8oOx9JoZ8ciIzZgI8qliwj4CXN57qxb5sjAf+7Kr Xn9J9y6CI6M54yzZkI15z+fIOeXi+WM= Received: from mx-prod-mc-04.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-564-OMg2fGSlMaSKCtOa9wDgZQ-1; Mon, 05 Aug 2024 17:09:21 -0400 X-MC-Unique: OMg2fGSlMaSKCtOa9wDgZQ-1 Received: from mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.4]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-04.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id DB15C19560B0; Mon, 5 Aug 2024 21:09:20 +0000 (UTC) Received: from merkur.fritz.box (unknown [10.39.193.224]) by mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id A18D830001AA; Mon, 5 Aug 2024 21:09:19 +0000 (UTC) From: Kevin Wolf To: qemu-block@nongnu.org Cc: kwolf@redhat.com, qemu-devel@nongnu.org Subject: [PULL 11/13] vvfat: Fix reading files with non-continuous clusters Date: Mon, 5 Aug 2024 23:08:49 +0200 Message-ID: <20240805210851.314076-12-kwolf@redhat.com> In-Reply-To: <20240805210851.314076-1-kwolf@redhat.com> References: <20240805210851.314076-1-kwolf@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.4 Received-SPF: pass client-ip=170.10.133.124; envelope-from=kwolf@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -21 X-Spam_score: -2.2 X-Spam_bar: -- X-Spam_report: (-2.2 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.143, 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_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=unavailable 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 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.amjadsharafi10@gmail.com> [kwolf: Simplified the patch based on Amjad's analysis and input] Signed-off-by: Kevin Wolf --- block/vvfat.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/block/vvfat.c b/block/vvfat.c index e3a83fbc88..8ffe8b3b9b 100644 --- a/block/vvfat.c +++ b/block/vvfat.c @@ -1369,8 +1369,9 @@ static int open_file(BDRVVVFATState* s,mapping_t* mapping) return -1; vvfat_close_current_file(s); s->current_fd = fd; - s->current_mapping = mapping; } + + s->current_mapping = mapping; return 0; }