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=unavailable 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 17DF4C2D0DB for ; Tue, 28 Jan 2020 14:24:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DEAC624691 for ; Tue, 28 Jan 2020 14:24:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1580221457; bh=5YYtm9ma19c214WP3Vz1E0GoAaNZU29FxW2eDLaO3UI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=TD2YaGSsy8KSrdKTDzS9/kJ83unlIeYgytguJHwzUF150xcoOVKKnuw9sOM8aOMC1 aU8LLVzKs+3K+2LumHD1PyBgPs1bWML3y8+HzY9F+9XHoA1oPhuorqqEA9aj0RN8yY UpTZ1r8/dzdFzohd5ET4v03vu7Z8wMi4BSbAnBJQ= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728057AbgA1OYQ (ORCPT ); Tue, 28 Jan 2020 09:24:16 -0500 Received: from mail.kernel.org ([198.145.29.99]:50816 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731405AbgA1OYN (ORCPT ); Tue, 28 Jan 2020 09:24:13 -0500 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (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 4860621739; Tue, 28 Jan 2020 14:24:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1580221452; bh=5YYtm9ma19c214WP3Vz1E0GoAaNZU29FxW2eDLaO3UI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Ov0VIQwndMtRm4q57rK1Yu386ySAeoukLXNPavYY4HAaCcXaP/8tDYZUlel+Dh2DW b1JDUi0Yl+hVgJi7Yzi11bqVy5Om79P5hRPU1IOiCm/h6JKHdr245KlCzMVL95mnUw YfD3Ec9SSQX6lTRMS7idC7ZzTEJ7qOFv3D6zIQpc= 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 4.9 193/271] staging: greybus: light: fix a couple double frees Date: Tue, 28 Jan 2020 15:05:42 +0100 Message-Id: <20200128135906.949065403@linuxfoundation.org> X-Mailer: git-send-email 2.25.0 In-Reply-To: <20200128135852.449088278@linuxfoundation.org> References: <20200128135852.449088278@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 9f01427f35f91..1cb82cc28aa76 100644 --- a/drivers/staging/greybus/light.c +++ b/drivers/staging/greybus/light.c @@ -1102,21 +1102,21 @@ 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