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=-8.4 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 F26FBC433FF for ; Tue, 30 Jul 2019 17:12:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C8061206A2 for ; Tue, 30 Jul 2019 17:12:29 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=poorly.run header.i=@poorly.run header.b="fnTPfuSO" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728758AbfG3RM2 (ORCPT ); Tue, 30 Jul 2019 13:12:28 -0400 Received: from mail-yw1-f67.google.com ([209.85.161.67]:33259 "EHLO mail-yw1-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725947AbfG3RM2 (ORCPT ); Tue, 30 Jul 2019 13:12:28 -0400 Received: by mail-yw1-f67.google.com with SMTP id l124so24045479ywd.0 for ; Tue, 30 Jul 2019 10:12:28 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=poorly.run; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=ImY2DybhOrcM2lI55Kc331ajwFUz03xP4fYhf/CoFd4=; b=fnTPfuSOS5xpzgI/dQJjNEhuWQ9V5NaVEYODjti6i+5CsuI18ORya/MuBcyjj5rKHw OGqBw9FvQA+91ljA6QWTZ+QjMYN6u0YAvnZ6iB6zumCkot1zgc+Ge8Zr36k9WdlYCPIq 5Qa+Xb7vJCv4lzx1IY48fS1EAyLA9/Pui0xCKvGCSTggjJbOVlLLVggs++kF07g3IQ+O MDdhIiresslcCgniwoC9JKTEDXB2NgciRQNn42Sv31gjZ6lsRJdl5wmhwdJ/hRypG8x5 /ePhj9cW+yWQYFKxEnLr1qEJp1o4qn6Mm25gYkJ3tlQqAsxDseFTGf3giZ5YNxic5xeY 6ocQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=ImY2DybhOrcM2lI55Kc331ajwFUz03xP4fYhf/CoFd4=; b=d1rjARXc5LCMcv6im5mlWZdQtMO52EjqW5mRyAPsSeRtObr9cm5qZAsTi8p3c5zIQv Doqtw5NyiXVi6NiB7TddRdWDUGL5j/njICK/58Ce6gxVQSn96aaTMt6DVfZuiXwjOdn9 saTvUUQ+fd1ADAmJrwkzeEd2O6Leik77k9FGNQ691qg8aDtO5knByPF70WFTtWKWaO5q E/ojM4h0EbcSEP4Ag4BPYeUxVHoKQg/o7tzRw1tKEkWfxzrG8zDBk1JtGOw88v7PKROx r07hScrctC6V8C/zP+JK/q/AylX+CD4QZAXL6ZoCaSXCBFLZpdVnduB0Ru0wY2W2Qblz u2Fw== X-Gm-Message-State: APjAAAXwby+PZIcz7k/mCmA3czq0dS6+D5bROnSF4hANfurvzH2fVFn8 Miikye754Iz4oXAfTDXeXHF6jQ== X-Google-Smtp-Source: APXvYqyrgMcO6GnWamgao3bXgcKs3QGF2zVbFr+EJ+2MO+luR4eSsfFewIm3vX0bBfYAvjwhDqbgCw== X-Received: by 2002:a0d:eb89:: with SMTP id u131mr71135814ywe.417.1564506747714; Tue, 30 Jul 2019 10:12:27 -0700 (PDT) Received: from localhost ([2620:0:1013:11:89c6:2139:5435:371d]) by smtp.gmail.com with ESMTPSA id x67sm15128373ywg.70.2019.07.30.10.12.27 (version=TLS1_3 cipher=AEAD-AES256-GCM-SHA384 bits=256/256); Tue, 30 Jul 2019 10:12:27 -0700 (PDT) Date: Tue, 30 Jul 2019 13:12:27 -0400 From: Sean Paul To: Chuhong Yuan Cc: Maarten Lankhorst , Maxime Ripard , Sean Paul , David Airlie , Daniel Vetter , dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] drm/modes: Fix unterminated strncpy Message-ID: <20190730171227.GS104440@art_vandelay> References: <20190730084032.26428-1-hslester96@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190730084032.26428-1-hslester96@gmail.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jul 30, 2019 at 04:40:32PM +0800, Chuhong Yuan wrote: > strncpy(dest, src, strlen(src)) leads to unterminated > dest, which is dangerous. > Fix it by using strscpy. > > Signed-off-by: Chuhong Yuan > --- > drivers/gpu/drm/drm_modes.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/drm_modes.c b/drivers/gpu/drm/drm_modes.c > index 80fcd5dc1558..170fc24e0f31 100644 > --- a/drivers/gpu/drm/drm_modes.c > +++ b/drivers/gpu/drm/drm_modes.c > @@ -1770,7 +1770,7 @@ bool drm_mode_parse_command_line_for_connector(const char *mode_option, > } > > if (named_mode) { > - strncpy(mode->name, name, mode_end); > + strscpy(mode->name, name, mode_end + 1); Shouldn't you be checking that mode_end + 1 is not > than the size of mode->name (ie: DRM_DISPLAY_MODE_LEN)? This still seems unsafe. Sean > } else { > ret = drm_mode_parse_cmdline_res_mode(name, mode_end, > parse_extras, > -- > 2.20.1 > -- Sean Paul, Software Engineer, Google / Chromium OS