From patchwork Fri Jun 19 14:32:08 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 223874 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,URIBL_BLOCKED,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 A8548C433DF for ; Fri, 19 Jun 2020 16:05:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 824DA207FC for ; Fri, 19 Jun 2020 16:05:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1592582715; bh=8DZyfMBj+GQYqoHgKvdO7+JnquptPSQNnrzE88QIKoc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=UZndmEdRsfIA9G4RRFyBi5hxro5Hq9bwrfyAg57cUSthiKVTAvn0MIZZG1w8GfrdR lvnficCXuw0Sf+n0j+ZBw28aN7FIkXs8mEZ5f0wx1LQu28VCyagK7D+M4SQTZWlcZB RbZmcFc3ViF8VwVYfOqdrPDxuU8x1jcfJG6We4JE= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2391978AbgFSPJx (ORCPT ); Fri, 19 Jun 2020 11:09:53 -0400 Received: from mail.kernel.org ([198.145.29.99]:39656 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2391973AbgFSPJv (ORCPT ); Fri, 19 Jun 2020 11:09:51 -0400 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 EEC8D21941; Fri, 19 Jun 2020 15:09:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1592579390; bh=8DZyfMBj+GQYqoHgKvdO7+JnquptPSQNnrzE88QIKoc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=NibE0LNvBhdulqksjjuITGrNtcTiBgJ2jEPOP1+c6GYHyuc8FHxiX94sZh2dP8hTH GA5mttl5ddSSvZj9I6hXWIh0Qzu0YefXmiG4nq/IGw8JIU0ePT71XM535SOavwc0eB xi1sywGDUJ8dj+zz3XHfdwnWQM1kgsDcrweNtSlM= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Dan Carpenter , Kalle Valo , Sasha Levin Subject: [PATCH 5.4 117/261] rtlwifi: Fix a double free in _rtl_usb_tx_urb_setup() Date: Fri, 19 Jun 2020 16:32:08 +0200 Message-Id: <20200619141655.480886333@linuxfoundation.org> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20200619141649.878808811@linuxfoundation.org> References: <20200619141649.878808811@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Dan Carpenter [ Upstream commit beb12813bc75d4a23de43b85ad1c7cb28d27631e ] Seven years ago we tried to fix a leak but actually introduced a double free instead. It was an understandable mistake because the code was a bit confusing and the free was done in the wrong place. The "skb" pointer is freed in both _rtl_usb_tx_urb_setup() and _rtl_usb_transmit(). The free belongs _rtl_usb_transmit() instead of _rtl_usb_tx_urb_setup() and I've cleaned the code up a bit to hopefully make it more clear. Fixes: 36ef0b473fbf ("rtlwifi: usb: add missing freeing of skbuff") Signed-off-by: Dan Carpenter Signed-off-by: Kalle Valo Link: https://lore.kernel.org/r/20200513093951.GD347693@mwanda Signed-off-by: Sasha Levin --- drivers/net/wireless/realtek/rtlwifi/usb.c | 8 ++------ 1 file changed, 2 insertions(+), 6 deletions(-) diff --git a/drivers/net/wireless/realtek/rtlwifi/usb.c b/drivers/net/wireless/realtek/rtlwifi/usb.c index 348b0072cdd6..c66c6dc00378 100644 --- a/drivers/net/wireless/realtek/rtlwifi/usb.c +++ b/drivers/net/wireless/realtek/rtlwifi/usb.c @@ -881,10 +881,8 @@ static struct urb *_rtl_usb_tx_urb_setup(struct ieee80211_hw *hw, WARN_ON(NULL == skb); _urb = usb_alloc_urb(0, GFP_ATOMIC); - if (!_urb) { - kfree_skb(skb); + if (!_urb) return NULL; - } _rtl_install_trx_info(rtlusb, skb, ep_num); usb_fill_bulk_urb(_urb, rtlusb->udev, usb_sndbulkpipe(rtlusb->udev, ep_num), skb->data, skb->len, _rtl_tx_complete, skb); @@ -898,7 +896,6 @@ static void _rtl_usb_transmit(struct ieee80211_hw *hw, struct sk_buff *skb, struct rtl_usb *rtlusb = rtl_usbdev(rtl_usbpriv(hw)); u32 ep_num; struct urb *_urb = NULL; - struct sk_buff *_skb = NULL; WARN_ON(NULL == rtlusb->usb_tx_aggregate_hdl); if (unlikely(IS_USB_STOP(rtlusb))) { @@ -907,8 +904,7 @@ static void _rtl_usb_transmit(struct ieee80211_hw *hw, struct sk_buff *skb, return; } ep_num = rtlusb->ep_map.ep_mapping[qnum]; - _skb = skb; - _urb = _rtl_usb_tx_urb_setup(hw, _skb, ep_num); + _urb = _rtl_usb_tx_urb_setup(hw, skb, ep_num); if (unlikely(!_urb)) { pr_err("Can't allocate urb. Drop skb!\n"); kfree_skb(skb);