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=-9.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 34FCFC2D0DB for ; Fri, 24 Jan 2020 11:29:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0C84122522 for ; Fri, 24 Jan 2020 11:29:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1579865393; bh=h8UpbCSI7U696KqtZ7M6siVRoIRZJSzbxGDPRlX24pc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=vcxIpd4Q1D5JhoyCsMQ0yfJgFOwGgabjapO5XrKH8DseTk3Tiyo9PhmiP1mbwaRoi VeGna/Dom1dZELmgTnKCRbvzWlxwQfYmn891n8ZGepa+QWi1/PXYytQidg9Cp4ysfO o0fhGrM8h4z7mDo8rTjut1WHLyjrWBeGSt2x61Ko= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2404114AbgAXL3w (ORCPT ); Fri, 24 Jan 2020 06:29:52 -0500 Received: from mail.kernel.org ([198.145.29.99]:46920 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2404094AbgAXL3s (ORCPT ); Fri, 24 Jan 2020 06:29:48 -0500 Received: from localhost (ip-213-127-102-57.ip.prioritytelecom.net [213.127.102.57]) (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 C56782077C; Fri, 24 Jan 2020 11:29:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1579865387; bh=h8UpbCSI7U696KqtZ7M6siVRoIRZJSzbxGDPRlX24pc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=bmDyDyKletNNTBCG/+YLDe3S0908M/mZC+eA946Hp/OE0izhT28MQ1t8bNy9R8nj4 AvJMNO1vQ+zCCydzXYwInu+jcYbmiv4COR2EiqdXP/Uyhs03FEBqeTVgFFNVb3M47r QC23nAvEyAH9c6tVU1PI5OLoksjV+z7zW0arPVHw= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Dan Carpenter , Rui Miguel Silva , Sasha Levin Subject: [PATCH 4.19 532/639] staging: greybus: light: fix a couple double frees Date: Fri, 24 Jan 2020 10:31:42 +0100 Message-Id: <20200124093155.533344333@linuxfoundation.org> X-Mailer: git-send-email 2.25.0 In-Reply-To: <20200124093047.008739095@linuxfoundation.org> References: <20200124093047.008739095@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Dan Carpenter [ Upstream commit 329101244f214952606359d254ae883b7109e1a5 ] The problem is in gb_lights_request_handler(). If we get a request to change the config then we release the light with gb_lights_light_release() and re-allocated it. However, if the allocation fails part way through then we call gb_lights_light_release() again. This can lead to a couple different double frees where we haven't cleared out the original values: gb_lights_light_v4l2_unregister(light); ... kfree(light->channels); kfree(light->name); I also made a small change to how we set "light->channels_count = 0;". The original code handled this part fine and did not cause a use after free but it was sort of complicated to read. Fixes: 2870b52bae4c ("greybus: lights: add lights implementation") Signed-off-by: Dan Carpenter Acked-by: Rui Miguel Silva Link: https://lore.kernel.org/r/20190829122839.GA20116@mwanda Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin --- drivers/staging/greybus/light.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/drivers/staging/greybus/light.c b/drivers/staging/greybus/light.c index 010ae1e9c7fbf..40680eaf3974f 100644 --- a/drivers/staging/greybus/light.c +++ b/drivers/staging/greybus/light.c @@ -1098,21 +1098,21 @@ static void gb_lights_channel_release(struct gb_channel *channel) static void gb_lights_light_release(struct gb_light *light) { int i; - int count; light->ready = false; - count = light->channels_count; - if (light->has_flash) gb_lights_light_v4l2_unregister(light); + light->has_flash = false; - for (i = 0; i < count; i++) { + for (i = 0; i < light->channels_count; i++) gb_lights_channel_release(&light->channels[i]); - light->channels_count--; - } + light->channels_count = 0; + kfree(light->channels); + light->channels = NULL; kfree(light->name); + light->name = NULL; } static void gb_lights_release(struct gb_lights *glights) -- 2.20.1