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=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,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 94BEDC49EAB for ; Mon, 28 Jun 2021 15:22:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7FBDA61949 for ; Mon, 28 Jun 2021 15:22:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238611AbhF1PYh (ORCPT ); Mon, 28 Jun 2021 11:24:37 -0400 Received: from mail.kernel.org ([198.145.29.99]:36572 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232654AbhF1PAi (ORCPT ); Mon, 28 Jun 2021 11:00:38 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 6406061D74; Mon, 28 Jun 2021 14:40:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1624891258; bh=I+GWBZ/4lDqFfHc3Y8W5fLceRDT6D7V3Ua+AYQ2cNYY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=TBsJRa6l9sTjlojt/rL6VwX8PnzkybuXzhxST3eLbZ3izHNNhuBkD4UfVC9w6uPR0 7Ej2KeP45U9XuvkxXHqNEkTHc7SSPZWtuwBPJOSL8WI6Ka8n69KaFVBczCvmSMtbqU amZivpAnwQebeVUpIeQd3uGPVPR/GLUjtyX/BEDeWzo02ShZSNI2Jg2gn/9/lBcyMR 6iGCJVWl+qLoohOwK4WC28+eh4MrHGbqv2gmdzRqgGKV8s6+gIIvY7UrxGI+aGT8sG bZJbTpiuU9DdYrZVrIxw77ftewmtMFn6uAbeeQARRv2/uw+mrjjmyjCN5xZkD1Ok92 KTuBjFhKAGqqw== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Pavel Skripkin , syzbot+f303e045423e617d2cad@syzkaller.appspotmail.com, "David S . Miller" , Sasha Levin Subject: [PATCH 4.9 61/71] net: caif: fix memory leak in ldisc_open Date: Mon, 28 Jun 2021 10:39:53 -0400 Message-Id: <20210628144003.34260-62-sashal@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210628144003.34260-1-sashal@kernel.org> References: <20210628144003.34260-1-sashal@kernel.org> MIME-Version: 1.0 X-KernelTest-Patch: http://kernel.org/pub/linux/kernel/v4.x/stable-review/patch-4.9.274-rc1.gz X-KernelTest-Tree: git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git X-KernelTest-Branch: linux-4.9.y X-KernelTest-Patches: git://git.kernel.org/pub/scm/linux/kernel/git/stable/stable-queue.git X-KernelTest-Version: 4.9.274-rc1 X-KernelTest-Deadline: 2021-06-30T14:39+00:00 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Pavel Skripkin [ Upstream commit 58af3d3d54e87bfc1f936e16c04ade3369d34011 ] Syzbot reported memory leak in tty_init_dev(). The problem was in unputted tty in ldisc_open() static int ldisc_open(struct tty_struct *tty) { ... ser->tty = tty_kref_get(tty); ... result = register_netdevice(dev); if (result) { rtnl_unlock(); free_netdev(dev); return -ENODEV; } ... } Ser pointer is netdev private_data, so after free_netdev() this pointer goes away with unputted tty reference. So, fix it by adding tty_kref_put() before freeing netdev. Reported-and-tested-by: syzbot+f303e045423e617d2cad@syzkaller.appspotmail.com Signed-off-by: Pavel Skripkin Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- drivers/net/caif/caif_serial.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/net/caif/caif_serial.c b/drivers/net/caif/caif_serial.c index 32834dad0b83..1243c2e5a86a 100644 --- a/drivers/net/caif/caif_serial.c +++ b/drivers/net/caif/caif_serial.c @@ -362,6 +362,7 @@ static int ldisc_open(struct tty_struct *tty) rtnl_lock(); result = register_netdevice(dev); if (result) { + tty_kref_put(tty); rtnl_unlock(); free_netdev(dev); return -ENODEV; -- 2.30.2