From patchwork Mon Feb 1 08:32:46 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Takashi Iwai X-Patchwork-Id: 12058369 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=-16.7 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,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 E2929C433DB for ; Mon, 1 Feb 2021 08:33:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 923CC64E33 for ; Mon, 1 Feb 2021 08:33:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232521AbhBAIde (ORCPT ); Mon, 1 Feb 2021 03:33:34 -0500 Received: from mx2.suse.de ([195.135.220.15]:57302 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231915AbhBAIdd (ORCPT ); Mon, 1 Feb 2021 03:33:33 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 8587EAD19; Mon, 1 Feb 2021 08:32:50 +0000 (UTC) From: Takashi Iwai To: Mauro Carvalho Chehab Cc: linux-media@vger.kernel.org, linux-kernel@vger.kernel.org, Stefan Seyfried , Robert Foss , Sean Young Subject: [PATCH v2 1/2] media: dvb-usb: Fix memory leak at error in dvb_usb_device_init() Date: Mon, 1 Feb 2021 09:32:46 +0100 Message-Id: <20210201083247.10760-2-tiwai@suse.de> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20210201083247.10760-1-tiwai@suse.de> References: <20210201083247.10760-1-tiwai@suse.de> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org dvb_usb_device_init() allocates a dvb_usb_device object, but it doesn't release the object by itself even at errors. The object is released in the callee side (dvb_usb_init()) in some error cases via dvb_usb_exit() call, but it also missed the object free in other error paths. And, the caller (it's only dvb_usb_device_init()) doesn't seem caring the resource management as well, hence those memories are leaked. This patch assures releasing the memory at the error path in dvb_usb_device_init(). Now dvb_usb_init() frees the resources it allocated but leaves the passed dvb_usb_device object intact. In turn, the dvb_usb_device object is released in dvb_usb_device_init() instead. We could use dvb_usb_exit() function for releasing everything in the callee (as it was used for some error cases in the original code), but releasing the passed object in the callee is non-intuitive and error-prone. So I took this approach (which is more standard in Linus kernel code) although it ended with a bit more open codes. Along with the change, the patch makes sure that USB intfdata is reset and don't return the bogus pointer to the caller of dvb_usb_device_init() at the error path, too. Cc: Signed-off-by: Takashi Iwai --- v1->v2: Fix double-free and reorganize the code drivers/media/usb/dvb-usb/dvb-usb-init.c | 47 ++++++++++++++++-------- 1 file changed, 31 insertions(+), 16 deletions(-) diff --git a/drivers/media/usb/dvb-usb/dvb-usb-init.c b/drivers/media/usb/dvb-usb/dvb-usb-init.c index c1a7634e27b4..c78158d12540 100644 --- a/drivers/media/usb/dvb-usb/dvb-usb-init.c +++ b/drivers/media/usb/dvb-usb/dvb-usb-init.c @@ -158,22 +158,20 @@ static int dvb_usb_init(struct dvb_usb_device *d, short *adapter_nums) if (d->props.priv_init != NULL) { ret = d->props.priv_init(d); - if (ret != 0) { - kfree(d->priv); - d->priv = NULL; - return ret; - } + if (ret != 0) + goto err_priv_init; } } /* check the capabilities and set appropriate variables */ dvb_usb_device_power_ctrl(d, 1); - if ((ret = dvb_usb_i2c_init(d)) || - (ret = dvb_usb_adapter_init(d, adapter_nums))) { - dvb_usb_exit(d); - return ret; - } + ret = dvb_usb_i2c_init(d); + if (ret) + goto err_i2c_init; + ret = dvb_usb_adapter_init(d, adapter_nums); + if (ret) + goto err_adapter_init; if ((ret = dvb_usb_remote_init(d))) err("could not initialize remote control."); @@ -181,6 +179,17 @@ static int dvb_usb_init(struct dvb_usb_device *d, short *adapter_nums) dvb_usb_device_power_ctrl(d, 0); return 0; + +err_adapter_init: + dvb_usb_adapter_exit(d); +err_i2c_init: + dvb_usb_i2c_exit(d); + if (d->priv && d->props.priv_destroy) + d->props.priv_destroy(d); +err_priv_init: + kfree(d->priv); + d->priv = NULL; + return ret; } /* determine the name and the state of the just found USB device */ @@ -281,15 +290,21 @@ int dvb_usb_device_init(struct usb_interface *intf, usb_set_intfdata(intf, d); - if (du != NULL) + ret = dvb_usb_init(d, adapter_nums); + if (ret) { + info("%s error while loading driver (%d)", desc->name, ret); + goto error; + } + + if (du) *du = d; - ret = dvb_usb_init(d, adapter_nums); + info("%s successfully initialized and connected.", desc->name); + return 0; - if (ret == 0) - info("%s successfully initialized and connected.", desc->name); - else - info("%s error while loading driver (%d)", desc->name, ret); + error: + usb_set_intfdata(intf, NULL); + kfree(d); return ret; } EXPORT_SYMBOL(dvb_usb_device_init);