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 8DB84C2B9F4 for ; Mon, 28 Jun 2021 15:01:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 72B6F61414 for ; Mon, 28 Jun 2021 15:01:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234701AbhF1PDt (ORCPT ); Mon, 28 Jun 2021 11:03:49 -0400 Received: from mail.kernel.org ([198.145.29.99]:53670 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236101AbhF1OqQ (ORCPT ); Mon, 28 Jun 2021 10:46:16 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 0458661D12; Mon, 28 Jun 2021 14:34:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1624890871; bh=el34oshqV5/fwop7i2A8DNlQAMiado0YSzkogBPgeVs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=nI7ZxeTpJFbuoJQkzzb/EVfKZwbzDSt7P+elsVMuXRDpHAQyJ8G6rS+Tu5yu0HW4a 2SmOVRZv1KoMaNHlTihRebLy7xfv4FIp0QtWBRkqcc1NVcbBdWx4v+zOqD47DwtgqY eyQ8N93FHIAOfRLyKfRFlRHjeMPr28qeYr2gvt5QWs/MM7uCTyUJ5PEkoq08k0VgV+ S3bAAVuNh/7jAcog0uGXzzwlCZqmNc20cbFW7eXc8VA/vQI3GoVFPDqWghRyUecyC6 dRvqTuA/akEMDhlbG+4/nRIkvim4jKDeUjV0zgjjxTXlm/Dm1kRI0zzK7eMTc/CT+D hybNtM1Ta/Dlg== 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 4.19 096/109] net: caif: fix memory leak in ldisc_open Date: Mon, 28 Jun 2021 10:32:52 -0400 Message-Id: <20210628143305.32978-97-sashal@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210628143305.32978-1-sashal@kernel.org> References: <20210628143305.32978-1-sashal@kernel.org> MIME-Version: 1.0 X-KernelTest-Patch: http://kernel.org/pub/linux/kernel/v4.x/stable-review/patch-4.19.196-rc1.gz X-KernelTest-Tree: git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git X-KernelTest-Branch: linux-4.19.y X-KernelTest-Patches: git://git.kernel.org/pub/scm/linux/kernel/git/stable/stable-queue.git X-KernelTest-Version: 4.19.196-rc1 X-KernelTest-Deadline: 2021-06-30T14:32+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 94d5ce9419ca..81ec17b9c49c 100644 --- a/drivers/net/caif/caif_serial.c +++ b/drivers/net/caif/caif_serial.c @@ -360,6 +360,7 @@ 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