From patchwork Mon Nov 16 08:23:05 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lukas Wunner X-Patchwork-Id: 325002 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=-9.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED 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 BB1E2C4742C for ; Mon, 16 Nov 2020 08:59:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6B72F221F9 for ; Mon, 16 Nov 2020 08:59:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728028AbgKPIg2 (ORCPT ); Mon, 16 Nov 2020 03:36:28 -0500 Received: from mailout2.hostsharing.net ([83.223.78.233]:42919 "EHLO mailout2.hostsharing.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727973AbgKPIg2 (ORCPT ); Mon, 16 Nov 2020 03:36:28 -0500 Received: from h08.hostsharing.net (h08.hostsharing.net [IPv6:2a01:37:1000::53df:5f1c:0]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "*.hostsharing.net", Issuer "COMODO RSA Domain Validation Secure Server CA" (not verified)) by mailout2.hostsharing.net (Postfix) with ESMTPS id 2BFDC10189A37; Mon, 16 Nov 2020 09:36:26 +0100 (CET) Received: from localhost (unknown [89.246.108.87]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-256) server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by h08.hostsharing.net (Postfix) with ESMTPSA id DBFCF6035EEE; Mon, 16 Nov 2020 09:36:25 +0100 (CET) X-Mailbox-Line: From bf610a9fc88376e2cdf661c4ad0bb275ee5f4f20 Mon Sep 17 00:00:00 2001 Message-Id: In-Reply-To: <73adc6ba84a4f968f2e1499a776e5c928fbdde56.1605512876.git.lukas@wunner.de> References: <73adc6ba84a4f968f2e1499a776e5c928fbdde56.1605512876.git.lukas@wunner.de> From: Lukas Wunner Date: Mon, 16 Nov 2020 09:23:05 +0100 Subject: [PATCH for-5.10] spi: rpc-if: Fix use-after-free on unbind To: Mark Brown Cc: linux-spi@vger.kernel.org, Sergei Shtylyov Precedence: bulk List-ID: X-Mailing-List: linux-spi@vger.kernel.org rpcif_spi_remove() accesses the driver's private data after calling spi_unregister_controller() even though that function releases the last reference on the spi_controller and thereby frees the private data. Fix by switching over to the new devm_spi_alloc_master() helper which keeps the private data accessible until the driver has unbound. Fixes: eb8d6d464a27 ("spi: add Renesas RPC-IF driver") Signed-off-by: Lukas Wunner Cc: # v5.9+: 5e844cc37a5c: spi: Introduce device-managed SPI controller allocation Cc: # v5.9+ Cc: Sergei Shtylyov --- drivers/spi/spi-rpc-if.c | 9 ++------- 1 file changed, 2 insertions(+), 7 deletions(-) diff --git a/drivers/spi/spi-rpc-if.c b/drivers/spi/spi-rpc-if.c index ed3e548227f4..3579675485a5 100644 --- a/drivers/spi/spi-rpc-if.c +++ b/drivers/spi/spi-rpc-if.c @@ -134,7 +134,7 @@ static int rpcif_spi_probe(struct platform_device *pdev) struct rpcif *rpc; int error; - ctlr = spi_alloc_master(&pdev->dev, sizeof(*rpc)); + ctlr = devm_spi_alloc_master(&pdev->dev, sizeof(*rpc)); if (!ctlr) return -ENOMEM; @@ -159,13 +159,8 @@ static int rpcif_spi_probe(struct platform_device *pdev) error = spi_register_controller(ctlr); if (error) { dev_err(&pdev->dev, "spi_register_controller failed\n"); - goto err_put_ctlr; + rpcif_disable_rpm(rpc); } - return 0; - -err_put_ctlr: - rpcif_disable_rpm(rpc); - spi_controller_put(ctlr); return error; }