From patchwork Mon Dec 7 08:17:06 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lukas Wunner X-Patchwork-Id: 339466 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=-13.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI, 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 60AEEC4361B for ; Mon, 7 Dec 2020 08:31:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E9F15225A9 for ; Mon, 7 Dec 2020 08:31:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725972AbgLGIbB (ORCPT ); Mon, 7 Dec 2020 03:31:01 -0500 Received: from bmailout3.hostsharing.net ([176.9.242.62]:49875 "EHLO bmailout3.hostsharing.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725905AbgLGIbB (ORCPT ); Mon, 7 Dec 2020 03:31:01 -0500 Received: from h08.hostsharing.net (h08.hostsharing.net [83.223.95.28]) (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 bmailout3.hostsharing.net (Postfix) with ESMTPS id 0169E100E4165; Mon, 7 Dec 2020 09:30:19 +0100 (CET) Received: by h08.hostsharing.net (Postfix, from userid 100393) id B5BC3AEA0; Mon, 7 Dec 2020 09:30:19 +0100 (CET) Message-Id: In-Reply-To: References: From: Lukas Wunner Date: Mon, 7 Dec 2020 09:17:06 +0100 Subject: [PATCH 06/17] spi: rpc-if: Fix use-after-free on unbind To: Mark Brown Cc: linux-spi@vger.kernel.org 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; }