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 X-Spam-Level: X-Spam-Status: No, score=-7.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS 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 911E3C433DF for ; Wed, 20 May 2020 12:13:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 58F64207D4 for ; Wed, 20 May 2020 12:13:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1589976824; bh=eiU9ulrXo9//FrP90hIhY+NjAvrqcWQpknvLFOmH76Y=; h=Date:From:To:Cc:Subject:In-Reply-To:References:List-ID:From; b=1cYriFxPT1JD0ug0ixtUcmv9ULfF717uB3JBpBqWrr9j2r7f7R0L+GcFxKanEir2a y0W73DGmO9Qdsfy+Xh3Ns8mwsi/9UmFTwGMyQ2bjTQU3uf2rMG6Wz3AnbDp1ERgc/0 H2CVNzTVxX4Pux4dx7L3UGON8Ai3EO85ae2VCqW8= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726525AbgETMNo (ORCPT ); Wed, 20 May 2020 08:13:44 -0400 Received: from mail.kernel.org ([198.145.29.99]:55100 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726224AbgETMNn (ORCPT ); Wed, 20 May 2020 08:13:43 -0400 Received: from disco-boy.misterjones.org (disco-boy.misterjones.org [51.254.78.96]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id E5C3620758; Wed, 20 May 2020 12:13:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1589976823; bh=eiU9ulrXo9//FrP90hIhY+NjAvrqcWQpknvLFOmH76Y=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=yZYGkFyv04VHheGle3iylFTms1gPrfCjLo5r5/jHnQ4a4Jyjfzga/2ShzAut47vdw pqtQf0GTjRxUhmA72d0NTk7T5j9+v/cmZyKKSPu8+8bJnC4esPrYZNWNqc7td/1+ha rMIuivgOWHgczc+3s4+IOpPQ7J6gwZTLZL37/SNA= Received: from disco-boy.misterjones.org ([51.254.78.96] helo=www.loen.fr) by disco-boy.misterjones.org with esmtpsa (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.92) (envelope-from ) id 1jbNbR-00Dv6k-BG; Wed, 20 May 2020 13:13:41 +0100 MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Date: Wed, 20 May 2020 13:13:41 +0100 From: Marc Zyngier To: Dan Carpenter Cc: Jonathan Cameron , Bartosz Golaszewski , Hartmut Knaack , Lars-Peter Clausen , Peter Meerwald-Stadler , Kate Stewart , Allison Randal , Linus Walleij , linux-iio@vger.kernel.org, kernel-janitors@vger.kernel.org Subject: Re: [PATCH] iio: dummy_evgen: Fix use after free on error in iio_dummy_evgen_create() In-Reply-To: <20200520120306.GD172354@mwanda> References: <20200520120306.GD172354@mwanda> User-Agent: Roundcube Webmail/1.4.4 Message-ID: <000f28ab442759baf6b6251b207aeabb@kernel.org> X-Sender: maz@kernel.org X-SA-Exim-Connect-IP: 51.254.78.96 X-SA-Exim-Rcpt-To: dan.carpenter@oracle.com, jic23@kernel.org, bgolaszewski@baylibre.com, knaack.h@gmx.de, lars@metafoo.de, pmeerw@pmeerw.net, kstewart@linuxfoundation.org, allison@lohutok.net, linus.walleij@linaro.org, linux-iio@vger.kernel.org, kernel-janitors@vger.kernel.org X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false Sender: linux-iio-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-iio@vger.kernel.org Hi Dan, On 2020-05-20 13:03, Dan Carpenter wrote: > We need to preserve the "iio_evgen->irq_sim_domain" error code before > we free "iio_evgen" otherwise it leads to a use after free. > > Fixes: 337cbeb2c13e ("genirq/irq_sim: Simplify the API") > Signed-off-by: Dan Carpenter > --- > drivers/iio/dummy/iio_dummy_evgen.c | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > diff --git a/drivers/iio/dummy/iio_dummy_evgen.c > b/drivers/iio/dummy/iio_dummy_evgen.c > index 409fe0f7df1c..ee85d596e528 100644 > --- a/drivers/iio/dummy/iio_dummy_evgen.c > +++ b/drivers/iio/dummy/iio_dummy_evgen.c > @@ -45,6 +45,8 @@ static struct iio_dummy_eventgen *iio_evgen; > > static int iio_dummy_evgen_create(void) > { > + int ret; > + > iio_evgen = kzalloc(sizeof(*iio_evgen), GFP_KERNEL); > if (!iio_evgen) > return -ENOMEM; > @@ -52,8 +54,9 @@ static int iio_dummy_evgen_create(void) > iio_evgen->irq_sim_domain = irq_domain_create_sim(NULL, > IIO_EVENTGEN_NO); > if (IS_ERR(iio_evgen->irq_sim_domain)) { > + ret = PTR_ERR(iio_evgen->irq_sim_domain); > kfree(iio_evgen); > - return PTR_ERR(iio_evgen->irq_sim_domain); > + return ret; > } > > mutex_init(&iio_evgen->lock); Nice catch. I've applied it to irq/irqchip-next, since the offending patch is queued there. Thanks, M. -- Jazz is not dead. It just smells funny...