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=-3.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no 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 AAD45C432C3 for ; Wed, 13 Nov 2019 20:08:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4F59E20679 for ; Wed, 13 Nov 2019 20:08:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726969AbfKMUI3 (ORCPT ); Wed, 13 Nov 2019 15:08:29 -0500 Received: from shards.monkeyblade.net ([23.128.96.9]:37170 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726179AbfKMUI3 (ORCPT ); Wed, 13 Nov 2019 15:08:29 -0500 Received: from localhost (unknown [IPv6:2601:601:9f00:1e2::3d5]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) (Authenticated sender: davem-davemloft) by shards.monkeyblade.net (Postfix) with ESMTPSA id 019AB11F5F7B9; Wed, 13 Nov 2019 12:08:28 -0800 (PST) Date: Wed, 13 Nov 2019 12:08:28 -0800 (PST) Message-Id: <20191113.120828.4034322769281345.davem@davemloft.net> To: jouni.hogander@unikie.com Cc: netdev@vger.kernel.org, socketcan@hartkopp.net, lukas.bulwahn@gmail.com Subject: Re: [PATCH] slip: Fix memory leak in slip_open error path From: David Miller In-Reply-To: <20191113114502.22462-1-jouni.hogander@unikie.com> References: <20191113114502.22462-1-jouni.hogander@unikie.com> X-Mailer: Mew version 6.8 on Emacs 26.1 Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.5.12 (shards.monkeyblade.net [149.20.54.216]); Wed, 13 Nov 2019 12:08:29 -0800 (PST) Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: jouni.hogander@unikie.com Date: Wed, 13 Nov 2019 13:45:02 +0200 > From: Jouni Hogander > > Driver/net/can/slcan.c is derived from slip.c. Memory leak was detected > by Syzkaller in slcan. Same issue exists in slip.c and this patch is > addressing the leak in slip.c. > > Here is the slcan memory leak trace reported by Syzkaller: ... > Signed-off-by: Jouni Hogander Applied and queued up for -stable. Looking at slip_open() while reviewing this patch, it has this test: if (!test_bit(SLF_INUSE, &sl->flags)) { /* Perform the low-level SLIP initialization. */ err = sl_alloc_bufs(sl, SL_MTU); if (err) goto err_free_chan; which seems bogus, because 'sl' here is always a freshly allocated object from sl_alloc(), which always provides an all-zeros value on sl->flags so this test always passes. It can therefore be removed.