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=-15.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 A01F3C433DB for ; Mon, 21 Dec 2020 12:12:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 423D32223E for ; Mon, 21 Dec 2020 12:12:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726548AbgLUMMb (ORCPT ); Mon, 21 Dec 2020 07:12:31 -0500 Received: from mail.kernel.org ([198.145.29.99]:51586 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726027AbgLUMMa (ORCPT ); Mon, 21 Dec 2020 07:12:30 -0500 Date: Mon, 21 Dec 2020 13:13:02 +0100 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1608552710; bh=lKlYUX1oZ4W0fvXWJJFlZMZRGAtGzH8EwXYJaUKAq5o=; h=From:To:Cc:Subject:References:In-Reply-To:From; b=oq4Wsg0pxlW4i1vtgb9fn+hl8S0mwsBvfvOJytEGqSItmYvtQm8Y3KqKiKiyTR+wh RHoi28+KX3e/qwOWfnLk9Ck14eUMkAyeXM1v7nlFj1zJMenrFzHVZYFxArajBk4EMA /DcU3vxfqb1tnOnrNISDD/hZewe/GtmmAi0cgKIY= From: Greg KH To: zhangqiumiao1@huwei.com Cc: jirislaby@kernel.org, linux-kernel@vger.kernel.org, zhangqiumiao Subject: Re: [PATCH] tty: add a check for NULL in con_init Message-ID: References: <1608551264-26117-1-git-send-email-zhangqiumiao1@huwei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1608551264-26117-1-git-send-email-zhangqiumiao1@huwei.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Dec 21, 2020 at 07:47:44PM +0800, zhangqiumiao1@huwei.com wrote: > From: zhangqiumiao > > Add a check for NULL in con_init in order to make sure kzalloc succeeds. > > Signed-off-by: zhangqiumiao > --- > drivers/tty/vt/vt.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/drivers/tty/vt/vt.c b/drivers/tty/vt/vt.c > index d04a162939a4..916f3370a136 100644 > --- a/drivers/tty/vt/vt.c > +++ b/drivers/tty/vt/vt.c > @@ -3486,11 +3486,15 @@ static int __init con_init(void) > > for (currcons = 0; currcons < MIN_NR_CONSOLES; currcons++) { > vc_cons[currcons].d = vc = kzalloc(sizeof(struct vc_data), GFP_NOWAIT); > + if (!vc) > + return -ENOMEM; > INIT_WORK(&vc_cons[currcons].SAK_work, vc_SAK); > tty_port_init(&vc->port); > visual_init(vc, currcons, 1); > /* Assuming vc->vc_{cols,rows,screenbuf_size} are sane here. */ > vc->vc_screenbuf = kzalloc(vc->vc_screenbuf_size, GFP_NOWAIT); > + if (!vc->vc_screenbuf) > + return -ENOMEM; Did you try to see what happens if you ever trigger this? Did you trigger this in real-world situations? Have you read the old email threads about where people tried to "fix" this and the problems that ended up happening? If not, please do so... Hint, I can not take this as you will NEVER hit this in a real system. thanks, greg k-h