From patchwork Tue Apr 5 07:25:57 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 557449 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id EAC6AC433FE for ; Tue, 5 Apr 2022 09:53:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244569AbiDEJyn (ORCPT ); Tue, 5 Apr 2022 05:54:43 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40628 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S244102AbiDEJOP (ORCPT ); Tue, 5 Apr 2022 05:14:15 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A69D73DDF6; Tue, 5 Apr 2022 02:00:38 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 52797B818F3; Tue, 5 Apr 2022 09:00:37 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9D611C385A0; Tue, 5 Apr 2022 09:00:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1649149236; bh=ROnrbzz1l46AppRuRx0ztfxHB96FsZrQXsAc4TedgXk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Hu4hLyKGP5TGp0UbFMQf5fyb6XZA4huXEUSByB/m7A+67gG/S8uw6TXscTIXPZNMn 8WLyiOFgCWv6Oo0ralos1Kxt6rBirc4QiwjWWk9DhDncKFFDUdayLGCZrhHtsCOcap qcPNiX5H8f7jm/tE/sMaLBO9nVhd0Ktj3iM5AEk8= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jiri Slaby , Sasha Levin Subject: [PATCH 5.16 0644/1017] mxser: fix xmit_buf leak in activate when LSR == 0xff Date: Tue, 5 Apr 2022 09:25:57 +0200 Message-Id: <20220405070413.399273841@linuxfoundation.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220405070354.155796697@linuxfoundation.org> References: <20220405070354.155796697@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Jiri Slaby [ Upstream commit cd3a4907ee334b40d7aa880c7ab310b154fd5cd4 ] When LSR is 0xff in ->activate() (rather unlike), we return an error. Provided ->shutdown() is not called when ->activate() fails, nothing actually frees the buffer in this case. Fix this by properly freeing the buffer in a designated label. We jump there also from the "!info->type" if now too. Fixes: 6769140d3047 ("tty: mxser: use the tty_port_open method") Signed-off-by: Jiri Slaby Link: https://lore.kernel.org/r/20220124071430.14907-6-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin --- drivers/tty/mxser.c | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) diff --git a/drivers/tty/mxser.c b/drivers/tty/mxser.c index 39458b42df7b..88d2f16fbf89 100644 --- a/drivers/tty/mxser.c +++ b/drivers/tty/mxser.c @@ -719,6 +719,7 @@ static int mxser_activate(struct tty_port *port, struct tty_struct *tty) struct mxser_port *info = container_of(port, struct mxser_port, port); unsigned long page; unsigned long flags; + int ret; page = __get_free_page(GFP_KERNEL); if (!page) @@ -728,9 +729,9 @@ static int mxser_activate(struct tty_port *port, struct tty_struct *tty) if (!info->type) { set_bit(TTY_IO_ERROR, &tty->flags); - free_page(page); spin_unlock_irqrestore(&info->slock, flags); - return 0; + ret = 0; + goto err_free_xmit; } info->port.xmit_buf = (unsigned char *) page; @@ -750,8 +751,10 @@ static int mxser_activate(struct tty_port *port, struct tty_struct *tty) if (capable(CAP_SYS_ADMIN)) { set_bit(TTY_IO_ERROR, &tty->flags); return 0; - } else - return -ENODEV; + } + + ret = -ENODEV; + goto err_free_xmit; } /* @@ -796,6 +799,10 @@ static int mxser_activate(struct tty_port *port, struct tty_struct *tty) spin_unlock_irqrestore(&info->slock, flags); return 0; +err_free_xmit: + free_page(page); + info->port.xmit_buf = NULL; + return ret; } /*