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 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 4C632D3E78C for ; Wed, 6 Nov 2024 09:54:32 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1t8ck0-0003bo-Ly; Wed, 06 Nov 2024 04:54:20 -0500 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 1t8cjz-0003bI-7R for qemu-devel@nongnu.org; Wed, 06 Nov 2024 04:54:19 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1t8cjw-0007kw-Cq for qemu-devel@nongnu.org; Wed, 06 Nov 2024 04:54:18 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1730886846; 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: in-reply-to:in-reply-to:references:references; bh=0EXNBo7zBth/JfJpiR61LmIIxKEPQf/aLGM/FZKPlI4=; b=ZcVpwqXizPTx5Cdie9PBoNpsikPRzjJJLHVOkuGDDuiCrh7rTxyTS3O6sawtsMY4QU4E/L UVvpRGsE0W7MhRzgXXwJ4cKbTC9lWe/jIg1vUtvVS4zPdT9fL+DwdSh87Bv6StYn/VGdHx 3UM9aR8dGpz/PHcesM/AQp8u3P6zlbQ= Received: from mx-prod-mc-01.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-395-9YxU5vWQNs2JmdfRg7bwQw-1; Wed, 06 Nov 2024 04:54:02 -0500 X-MC-Unique: 9YxU5vWQNs2JmdfRg7bwQw-1 X-Mimecast-MFC-AGG-ID: 9YxU5vWQNs2JmdfRg7bwQw Received: from mx-prod-int-04.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-04.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.40]) (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-01.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 475871955F42; Wed, 6 Nov 2024 09:54:01 +0000 (UTC) Received: from redhat.com (dhcp-192-228.str.redhat.com [10.33.192.228]) by mx-prod-int-04.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 1BDC019560AA; Wed, 6 Nov 2024 09:53:58 +0000 (UTC) Date: Wed, 6 Nov 2024 10:53:56 +0100 From: Kevin Wolf To: Dmitry Frolov Cc: stefanha@redhat.com, den@openvz.org, sdl.qemu@linuxtesting.org, qemu-devel@nongnu.org, qemu-block@nongnu.org Subject: Re: [PATCH] block: fix possible int overflow Message-ID: References: <20241106080521.219255-2-frolov@swemel.ru> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20241106080521.219255-2-frolov@swemel.ru> X-Scanned-By: MIMEDefang 3.0 on 10.30.177.40 Received-SPF: pass client-ip=170.10.129.124; envelope-from=kwolf@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -23 X-Spam_score: -2.4 X-Spam_bar: -- X-Spam_report: (-2.4 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.34, 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_H2=-0.001, RCVD_IN_VALIDITY_CERTIFIED_BLOCKED=0.001, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 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 [ Cc: qemu-block ] Am 06.11.2024 um 09:04 hat Dmitry Frolov geschrieben: > The sum "cluster_index + count" may overflow uint32_t. > > Found by Linux Verification Center (linuxtesting.org) with SVACE. > > Signed-off-by: Dmitry Frolov Thanks, applied to the block branch. While trying to check if this can be triggered in practice, I found this line in parallels_fill_used_bitmap(): s->used_bmap_size = DIV_ROUND_UP(payload_bytes, s->cluster_size); s->used_bmap_size is unsigned long, payload_bytes is the int64_t result of bdrv_getlength() for the image file, which could certainly be made more than 4 GB * cluster_size. I think we need an overflow check there, too. When allocate_clusters() calculates new_usedsize, it doesn't seem to consider the overflow case either. Denis, can you take a look? Kevin