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,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 AEC15C4743C for ; Mon, 21 Jun 2021 18:06:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9A35760E0C for ; Mon, 21 Jun 2021 18:06:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232323AbhFUSIS (ORCPT ); Mon, 21 Jun 2021 14:08:18 -0400 Received: from mail.kernel.org ([198.145.29.99]:47216 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234292AbhFUSFD (ORCPT ); Mon, 21 Jun 2021 14:05:03 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 3D108613AB; Mon, 21 Jun 2021 17:56:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1624298176; bh=I+GWBZ/4lDqFfHc3Y8W5fLceRDT6D7V3Ua+AYQ2cNYY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=PwaFlp6ZS9C1MPQHfb0BVn5seKGJnj6q/I55N84pGyBMI/5nDIbia4zCgbQEy/r5o 5GkTz1E5ARhzKv7TyJG5joVPgEw2QKwhRVTDMp83TI2Ax6C0ZrsqfSL/iwn6rpW1PM QCmSKvltzQwcB5GE/8gcSYQ9EaWHwdfG6GQ8TSjWgZoYXT9M2qLC6EYkuOEiTpgsp+ c2AF3t6gdEe78p3oaagHk3Cw8JMPVb7924D9wUFpaaE0WgA1OtocWI+er23smaeICz AuWWeX5KlGOWEGLGuZAEDdJNWHg/HjKu8AN9ZRzEdpvyRPeHo0D99L1/AXPOrFonoD 4j/+QNSch2PRQ== 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 , netdev@vger.kernel.org Subject: [PATCH AUTOSEL 4.4 5/9] net: caif: fix memory leak in ldisc_open Date: Mon, 21 Jun 2021 13:56:03 -0400 Message-Id: <20210621175608.736581-5-sashal@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210621175608.736581-1-sashal@kernel.org> References: <20210621175608.736581-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: netdev@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