From patchwork Tue Feb 28 09:03:04 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hans de Goede X-Patchwork-Id: 658410 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 515FDC64ED6 for ; Tue, 28 Feb 2023 09:03:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229756AbjB1JDz (ORCPT ); Tue, 28 Feb 2023 04:03:55 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45340 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229644AbjB1JDy (ORCPT ); Tue, 28 Feb 2023 04:03:54 -0500 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CD4D4A26D for ; Tue, 28 Feb 2023 01:03:13 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1677574993; 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=sirfqygwoRQ697x8s2eJZOuvpqe/7SKCi+yX/4Aaiqw=; b=fwAoKuhRk33Z2WpWolKJhgzQRi687X4N0mBmBBohyqJvs0tI835uNE0Na4Y2Y5bfpSzKMQ A0C6CmSGLexi9QV3CCKyifEi4PZCK3Y3L343agHnUDEwjDEZ1oLkAzLeGkWv/dVu6AH8O+ Xwhaq0lVftpYoEje2k4/z+gqCaF0ZlA= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-618-csfzjiK4M_KF7a-7dT3fgg-1; Tue, 28 Feb 2023 04:03:08 -0500 X-MC-Unique: csfzjiK4M_KF7a-7dT3fgg-1 Received: from smtp.corp.redhat.com (int-mx09.intmail.prod.int.rdu2.redhat.com [10.11.54.9]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 70ECF857A94; Tue, 28 Feb 2023 09:03:08 +0000 (UTC) Received: from shalem.redhat.com (unknown [10.39.194.124]) by smtp.corp.redhat.com (Postfix) with ESMTP id 9B901492B0F; Tue, 28 Feb 2023 09:03:07 +0000 (UTC) From: Hans de Goede To: Greg Kroah-Hartman , Heikki Krogerus Cc: Hans de Goede , linux-usb@vger.kernel.org, stable@vger.kernel.org Subject: [PATCH 2/3] usb: ucsi: Fix ucsi->connector race Date: Tue, 28 Feb 2023 10:03:04 +0100 Message-Id: <20230228090305.9335-2-hdegoede@redhat.com> In-Reply-To: <20230228090305.9335-1-hdegoede@redhat.com> References: <20230228090305.9335-1-hdegoede@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.9 Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org ucsi_init() which runs from a workqueue sets ucsi->connector and on an error will clear it again. ucsi->connector gets dereferenced by both ucsi_connector_change() and ucsi_resume(), both check for ucsi->connector being NULL in case ucsi_init() has not finished yet; or in case ucsi_init() has failed. ucsi_init() setting ucsi->connector and then clearing it again on an error creates a race where the check in the consumers may pass, only to have ucsi->connector free-ed underneath them when ucsi_init() hits an error. Fix this race by making ucsi_init() store the connector array in a local variable and only assign it to ucsi->connector on success. Fixes: bdc62f2bae8f ("usb: typec: ucsi: Simplified registration and I/O API") Cc: stable@vger.kernel.org Signed-off-by: Hans de Goede --- drivers/usb/typec/ucsi/ucsi.c | 20 ++++++++------------ 1 file changed, 8 insertions(+), 12 deletions(-) diff --git a/drivers/usb/typec/ucsi/ucsi.c b/drivers/usb/typec/ucsi/ucsi.c index e762897cb25a..796ae230c60b 100644 --- a/drivers/usb/typec/ucsi/ucsi.c +++ b/drivers/usb/typec/ucsi/ucsi.c @@ -1045,9 +1045,8 @@ static struct fwnode_handle *ucsi_find_fwnode(struct ucsi_connector *con) return NULL; } -static int ucsi_register_port(struct ucsi *ucsi, int index) +static int ucsi_register_port(struct ucsi *ucsi, int index, struct ucsi_connector *con) { - struct ucsi_connector *con = &ucsi->connector[index]; struct typec_capability *cap = &con->typec_cap; enum typec_accessory *accessory = cap->accessory; enum usb_role u_role = USB_ROLE_NONE; @@ -1210,7 +1209,7 @@ static int ucsi_register_port(struct ucsi *ucsi, int index) */ static int ucsi_init(struct ucsi *ucsi) { - struct ucsi_connector *con; + struct ucsi_connector *con, *connector; u64 command; int ret; int i; @@ -1241,16 +1240,15 @@ static int ucsi_init(struct ucsi *ucsi) } /* Allocate the connectors. Released in ucsi_unregister() */ - ucsi->connector = kcalloc(ucsi->cap.num_connectors + 1, - sizeof(*ucsi->connector), GFP_KERNEL); - if (!ucsi->connector) { + connector = kcalloc(ucsi->cap.num_connectors + 1, sizeof(*connector), GFP_KERNEL); + if (!connector) { ret = -ENOMEM; goto err_reset; } /* Register all connectors */ for (i = 0; i < ucsi->cap.num_connectors; i++) { - ret = ucsi_register_port(ucsi, i); + ret = ucsi_register_port(ucsi, i, &connector[i]); if (ret) goto err_unregister; } @@ -1262,10 +1260,11 @@ static int ucsi_init(struct ucsi *ucsi) if (ret < 0) goto err_unregister; + ucsi->connector = connector; return 0; err_unregister: - for (con = ucsi->connector; con->port; con++) { + for (con = connector; con->port; con++) { ucsi_unregister_partner(con); ucsi_unregister_altmodes(con, UCSI_RECIPIENT_CON); ucsi_unregister_port_psy(con); @@ -1274,10 +1273,7 @@ static int ucsi_init(struct ucsi *ucsi) typec_unregister_port(con->port); con->port = NULL; } - - kfree(ucsi->connector); - ucsi->connector = NULL; - + kfree(connector); err_reset: memset(&ucsi->cap, 0, sizeof(ucsi->cap)); ucsi_reset_ppm(ucsi);