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 4B6DBC4743C for ; Mon, 21 Jun 2021 18:00:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 329AF60C41 for ; Mon, 21 Jun 2021 18:00:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233933AbhFUSCw (ORCPT ); Mon, 21 Jun 2021 14:02:52 -0400 Received: from mail.kernel.org ([198.145.29.99]:45232 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233326AbhFUSAH (ORCPT ); Mon, 21 Jun 2021 14:00:07 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id CC3CE61040; Mon, 21 Jun 2021 17:54:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1624298067; bh=ZhudtaCtWlly0EAeh0317uFcm9vgXLNyBmrC/gLT+7s=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=q3Im13A5gFzn3wCi+j6MThqdwjiGoghJJVm7UgSMxBUgMRqa0m+lawC2FlaXJR4bY y/uU4YlCSvGaXhHStkpREmTwJ043+WHFYBXrx69rB/Eh3+Oru/2MP1nw6aePburZWC rtVZUmh03Ys8Zp0pX3sswl7j0v6lDLttCiPZe11hBLkpOHuBp709KMue45/Q0pbSZ6 CITDcDpkwOwe5BMxPU0dVve+GsET4MEwjp2Synpza3JAZou5kML2Fup9Yw6aR0xFBf Re6+9Ndf90/9gS1ZKEfAHD1/0BtYFz2oJpo3OkvPX7kHoeY3DDDochCFu5EKxRJfa3 xuAH9HHjgKg6Q== 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 5.4 15/26] net: caif: fix memory leak in ldisc_open Date: Mon, 21 Jun 2021 13:53:48 -0400 Message-Id: <20210621175400.735800-15-sashal@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210621175400.735800-1-sashal@kernel.org> References: <20210621175400.735800-1-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: 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 0f2bee59a82b..0bc7f6518fb3 100644 --- a/drivers/net/caif/caif_serial.c +++ b/drivers/net/caif/caif_serial.c @@ -351,6 +351,7 @@ 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