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 lists1p.gnu.org (lists1p.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 A2907C4452D for ; Tue, 21 Jul 2026 17:07:43 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists1p.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1wmDuc-0004oh-QP; Tue, 21 Jul 2026 13:05:46 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists1p.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1wmDua-0004nt-Sq for qemu-devel@nongnu.org; Tue, 21 Jul 2026 13:05:45 -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 1wmDuZ-00074p-EC for qemu-devel@nongnu.org; Tue, 21 Jul 2026 13:05:44 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1784653542; 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=fEJwEoGhO12AmbhN6O3Bb2G+2hsVAlx3B1Qba5SOvGY=; b=Ys4+NuDyaHiwuY11vAaz2+X/n5by2fKiN9CCvRM9OdhNTKI8sA3rhABbrhOxHqjE1mYiRQ U9TUDNSTN/iWnLI6bS5pieFJjB2sqwdb6phnR/aJbDTbMNOeGDZfSSVvIm4IZnxjm0vPc2 7KiTdZ9rU6BV+wLZHv/ib8Nj4Gzx4u0= Received: from mx-prod-mc-08.mail-002.prod.us-west-2.aws.redhat.com (ec2-35-165-154-97.us-west-2.compute.amazonaws.com [35.165.154.97]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-326-x3C2vHO0Pyu__YctxsBDRQ-1; Tue, 21 Jul 2026 13:05:39 -0400 X-MC-Unique: x3C2vHO0Pyu__YctxsBDRQ-1 X-Mimecast-MFC-AGG-ID: x3C2vHO0Pyu__YctxsBDRQ_1784653538 Received: from mx-prod-int-10.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-10.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.95]) (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-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 097221809CB6; Tue, 21 Jul 2026 17:05:38 +0000 (UTC) Received: from corto.redhat.com (unknown [10.44.48.82]) by mx-prod-int-10.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 9F0241598; Tue, 21 Jul 2026 17:05:36 +0000 (UTC) From: =?UTF-8?q?C=C3=A9dric=20Le=20Goater?= To: qemu-devel@nongnu.org Cc: Thanos Makatos , =?UTF-8?q?C=C3=A9dric=20Le=20Goater?= Subject: [PULL 08/13] vfio-user: vfio_user_get_region_info: prevent excessive malloc Date: Tue, 21 Jul 2026 19:05:13 +0200 Message-ID: <20260721170518.4160785-9-clg@redhat.com> In-Reply-To: <20260721170518.4160785-1-clg@redhat.com> References: <20260721170518.4160785-1-clg@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 3.6 on 10.30.177.95 Received-SPF: permerror client-ip=170.10.133.124; envelope-from=clg@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, 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_PASS=-0.001, T_SPF_PERMERROR=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: qemu development 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: Thanos Makatos If the vfio-user server responds with a value larger than max_xfer_size vfio_device_get_region_info() blindly uses it in the next loop in g_realloc. An value larger than max_xfer_size is anyway rejected by the check at the beginning of vfio_user_get_region_info(), however that only happens _after_ the g_realloc, and if that value is excessively large it can cause g_realloc to fail, so check it here. Signed-off-by: Thanos Makatos Fixes: 667866d66620 ("vfio-user: implement VFIO_USER_DEVICE_GET_REGION_INFO") Reviewed-by: Cédric Le Goater Link: https://lore.kernel.org/qemu-devel/20260721122643.30985-5-thanos.makatos@nutanix.com Signed-off-by: Cédric Le Goater --- hw/vfio-user/device.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/hw/vfio-user/device.c b/hw/vfio-user/device.c index 3d12e8b2a20eb96fb1a8a944070d13bf0e049b67..008e5cf6877c84c3d0cf33f25a6ac9a4cf231e06 100644 --- a/hw/vfio-user/device.c +++ b/hw/vfio-user/device.c @@ -170,6 +170,16 @@ static int vfio_user_get_region_info(VFIOUserProxy *proxy, return -EINVAL; } + /* + * The server can respond with a larger argsz in the reply to request a + * larger buffer on the next iteration via vfio_device_get_region_info(). + * Reject values that would trigger an oversized realloc. + */ + if (msgp->argsz > proxy->max_xfer_size) { + error_printf("vfio_user_get_region_info reply argsz too large\n"); + return -E2BIG; + } + memcpy(info, &msgp->argsz, info->argsz); /* -- 2.55.0