From patchwork Wed Jun 30 14:11:43 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alain Volmat X-Patchwork-Id: 1498920 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=23.128.96.18; helo=vger.kernel.org; envelope-from=linux-i2c-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=foss.st.com header.i=@foss.st.com header.a=rsa-sha256 header.s=selector1 header.b=Z1d9v2V2; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by ozlabs.org (Postfix) with ESMTP id 4GFNc30qPQz9sRf for ; Thu, 1 Jul 2021 00:13:23 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235271AbhF3OPt (ORCPT ); Wed, 30 Jun 2021 10:15:49 -0400 Received: from mx07-00178001.pphosted.com ([185.132.182.106]:49320 "EHLO mx07-00178001.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235088AbhF3OPl (ORCPT ); Wed, 30 Jun 2021 10:15:41 -0400 Received: from pps.filterd (m0241204.ppops.net [127.0.0.1]) by mx07-00178001.pphosted.com (8.16.0.43/8.16.0.43) with SMTP id 15UEAY0h002860; Wed, 30 Jun 2021 16:12:58 +0200 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=foss.st.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : mime-version : content-type; s=selector1; bh=2vk0SM1w1rYwBoKsGyRqoKEvl040SvG0KTlIbUrKgsc=; b=Z1d9v2V2HDrqhk0MZUnAz3mbRajKOrOhUStToRb4SFG4plLLFkABzrzbvm3vF6p2ZJkQ 8mAL1QZXGXVJerZ4E94/hRGdgTANjyqGNo1RgAfvE+24aa92S3mMwmuTizzuiIcXAttR Q2zBtFHhBxr1OliAftxJELttwA7le6qd6X/vNKKoww+qhcHkChQXm8FX2ldCrORgh8l1 nJiW3SRWXnHeZThK3CD184V/9oQNUwSnCeeFpye+x+HmhpoPJ951VWP+fQ/RPFmcSFHu cngiVrGseXFTM0rryX7Y7yi2sHLNmdoPama/w4SJaeuSZve1zKvxtJtVhB3AVMMIgU5l Ow== Received: from beta.dmz-eu.st.com (beta.dmz-eu.st.com [164.129.1.35]) by mx07-00178001.pphosted.com with ESMTP id 39g4kpy7f2-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Wed, 30 Jun 2021 16:12:58 +0200 Received: from euls16034.sgp.st.com (euls16034.sgp.st.com [10.75.44.20]) by beta.dmz-eu.st.com (STMicroelectronics) with ESMTP id EF43810003A; Wed, 30 Jun 2021 16:12:57 +0200 (CEST) Received: from Webmail-eu.st.com (sfhdag2node3.st.com [10.75.127.6]) by euls16034.sgp.st.com (STMicroelectronics) with ESMTP id E465F23151D; Wed, 30 Jun 2021 16:12:57 +0200 (CEST) Received: from localhost (10.75.127.48) by SFHDAG2NODE3.st.com (10.75.127.6) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Wed, 30 Jun 2021 16:12:57 +0200 From: Alain Volmat To: , CC: , , , , , , , Subject: [PATCH 3/3] i2c: stm32f7: prevent calling slave handling if no slave running Date: Wed, 30 Jun 2021 16:11:43 +0200 Message-ID: <1625062303-15327-4-git-send-email-alain.volmat@foss.st.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1625062303-15327-1-git-send-email-alain.volmat@foss.st.com> References: <1625062303-15327-1-git-send-email-alain.volmat@foss.st.com> MIME-Version: 1.0 X-Originating-IP: [10.75.127.48] X-ClientProxiedBy: SFHDAG1NODE2.st.com (10.75.127.2) To SFHDAG2NODE3.st.com (10.75.127.6) X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.391,18.0.790 definitions=2021-06-30_06:2021-06-29,2021-06-30 signatures=0 Precedence: bulk List-ID: X-Mailing-List: linux-i2c@vger.kernel.org Slave interrupt handler should only be called if there is actually a slave registered and running to avoid accessing an invalid pointer. Without this commit, an OOPS can be generated due to a NULL ptr dereference while receiving an IT when there is no master transfer and no slave running: - stm32f7_i2c_isr_event - no master_mode hence calling stm32f7_i2c_slave_isr_event - access to i2c_dev->slave_running leading to oops due to slave_running being NULL. Fixes: 60d609f30de2 ("i2c: i2c-stm32f7: Add slave support") Signed-off-by: Alain Volmat --- drivers/i2c/busses/i2c-stm32f7.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/drivers/i2c/busses/i2c-stm32f7.c b/drivers/i2c/busses/i2c-stm32f7.c index 0d99c075deb2..2cc9bb0f6d7f 100644 --- a/drivers/i2c/busses/i2c-stm32f7.c +++ b/drivers/i2c/busses/i2c-stm32f7.c @@ -1497,10 +1497,14 @@ static irqreturn_t stm32f7_i2c_isr_event(int irq, void *data) u32 status, mask; int ret = IRQ_HANDLED; - /* Check if the interrupt if for a slave device */ + /* Check if the interrupt is for a slave device */ if (!i2c_dev->master_mode) { - ret = stm32f7_i2c_slave_isr_event(i2c_dev); - return ret; + if (i2c_dev->slave_running) + return stm32f7_i2c_slave_isr_event(i2c_dev); + + dev_warn_ratelimited(i2c_dev->dev, + "Unexpected IT received: ISR:0x%x\n", + readl_relaxed(i2c_dev->base + STM32F7_I2C_ISR)); } status = readl_relaxed(i2c_dev->base + STM32F7_I2C_ISR);