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=-3.0 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS, T_DKIMWL_WL_HIGH,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham 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 3A4BDC433F4 for ; Wed, 29 Aug 2018 02:24:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E4FDE20684 for ; Wed, 29 Aug 2018 02:24:01 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=arista.com header.i=@arista.com header.b="isqoiePY" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E4FDE20684 Authentication-Results: mail.kernel.org; dmarc=fail (p=quarantine dis=none) header.from=arista.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727416AbeH2GSa (ORCPT ); Wed, 29 Aug 2018 02:18:30 -0400 Received: from mail-ed1-f68.google.com ([209.85.208.68]:40557 "EHLO mail-ed1-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725199AbeH2GS2 (ORCPT ); Wed, 29 Aug 2018 02:18:28 -0400 Received: by mail-ed1-f68.google.com with SMTP id e19-v6so2774748edq.7 for ; Tue, 28 Aug 2018 19:23:57 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=arista.com; s=googlenew; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=h2rsiF9P7p4ynflggwgQAjCIBGcKV6Izc/9GngY6csc=; b=isqoiePYDPMoVP/o8d00tZRP2sQ/VhKkInY30WDLQEPiDInVt1wvjSXMc0MJrWuo52 4U6PFk+AJzsfyJo4sj0rwZ6NHITnJDl4aukOdDCl/Ge52V7NsE1pXIqLTuD/MCcuTSlH 4lo04m9LeQYTm6NBIMDgtrejHvezq77Ycq5mraSpljPR2iVVinH+s+DnMxtx1QDWVkgm AlePicT4FBJK27EZlxIl/roh0EuS9oJ8D86tXq2WsAOpX/j8jznwKmt0C3Al6UFv9W1z AOK+BHWS53Q8gGOI6CGA52IMfLTlfqlmdGRl9wDXNP/slbtRDxT2XpMf5LjzmNNFIzeN 9nPw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=h2rsiF9P7p4ynflggwgQAjCIBGcKV6Izc/9GngY6csc=; b=VN6OF56tICt5K8YKCE6gEX8odoJhBCruUDBLxtX5fH6IjRklyrkU8l/BKo+/9leWER oPkcI80FFrruwfVrzGo0ZevTsFGSb7dqCt4ZNkVzZBQ2xoLKABYYlF/DChvlULdjLPBk n9qVYaCpGt3oh5Bd/XvZhe1C9pmIi/bD0ooBr2p/qAbNfw9L5ot0r6uN9rlLVgWwyd9Z imKJIPKvEOj8KS5WKsVb0PoKm2RrB5xSNDZpDIncBsUl93+E4iMHrFKEW3tYKz+BkQYO k5+TSmJTo1ecJU4VJsAHbNkIFj70j7w5uWaOjd29kZrITSBIDiVp6LK1yES99pgvh4bQ VJyw== X-Gm-Message-State: APzg51B9Arxc8QfIPfBrGQdIai+fCc7lCR4Kg35o+43qAXOoFTHVzyTc Li9fcy5Mr7mE0OzRC9rlMvDjM5T9TWE= X-Google-Smtp-Source: ANB0VdZPPNJxRzqD0vTiWY3Ezb/N0x1I9xIz1hVA6fevpcssiRUlCNzrd4Wzo1GUf02/+cPJhg5Fog== X-Received: by 2002:a50:aa3b:: with SMTP id o56-v6mr5199849edc.23.1535509436176; Tue, 28 Aug 2018 19:23:56 -0700 (PDT) Received: from dhcp.ire.aristanetworks.com ([217.173.96.166]) by smtp.gmail.com with ESMTPSA id f26-v6sm1236367edb.28.2018.08.28.19.23.55 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Tue, 28 Aug 2018 19:23:55 -0700 (PDT) From: Dmitry Safonov To: linux-kernel@vger.kernel.org Cc: Dmitry Safonov <0x7f454c46@gmail.com>, Dmitry Safonov , Daniel Axtens , Dmitry Vyukov , Michael Neuling , Mikulas Patocka , =?UTF-8?q?Pasi=20K=C3=A4rkk=C3=A4inen?= , Peter Hurley , Sergey Senozhatsky , Tan Xiaojun , Greg Kroah-Hartman , Jiri Slaby , stable@vger.kernel.org Subject: [PATCH 1/4] tty: Drop tty->count on tty_reopen() failure Date: Wed, 29 Aug 2018 03:23:50 +0100 Message-Id: <20180829022353.23568-2-dima@arista.com> X-Mailer: git-send-email 2.13.6 In-Reply-To: <20180829022353.23568-1-dima@arista.com> References: <20180829022353.23568-1-dima@arista.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org In case of tty_ldisc_reinit() failure, tty->count should be decremented back, otherwise we will never release_tty(). Never seen it in the real life, but it seems not really hard to hit. Cc: Greg Kroah-Hartman Cc: Jiri Slaby Cc: stable@vger.kernel.org Signed-off-by: Dmitry Safonov --- drivers/tty/tty_io.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c index 32bc3e3fe4d3..5e5da9acaf0a 100644 --- a/drivers/tty/tty_io.c +++ b/drivers/tty/tty_io.c @@ -1255,6 +1255,7 @@ static void tty_driver_remove_tty(struct tty_driver *driver, struct tty_struct * static int tty_reopen(struct tty_struct *tty) { struct tty_driver *driver = tty->driver; + int retval; if (driver->type == TTY_DRIVER_TYPE_PTY && driver->subtype == PTY_TYPE_MASTER) @@ -1268,10 +1269,14 @@ static int tty_reopen(struct tty_struct *tty) tty->count++; - if (!tty->ldisc) - return tty_ldisc_reinit(tty, tty->termios.c_line); + if (tty->ldisc) + return 0; - return 0; + retval = tty_ldisc_reinit(tty, tty->termios.c_line); + if (retval) + tty->count--; + + return retval; } /** -- 2.13.6