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=-13.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY 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 C2ECFC433E0 for ; Tue, 19 Jan 2021 18:42:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 816002310C for ; Tue, 19 Jan 2021 18:42:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2391405AbhASSje (ORCPT ); Tue, 19 Jan 2021 13:39:34 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49592 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2391267AbhASSg0 (ORCPT ); Tue, 19 Jan 2021 13:36:26 -0500 Received: from bhuna.collabora.co.uk (bhuna.collabora.co.uk [IPv6:2a00:1098:0:82:1000:25:2eeb:e3e3]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1874DC061757 for ; Tue, 19 Jan 2021 10:35:45 -0800 (PST) Received: from [127.0.0.1] (localhost [127.0.0.1]) (Authenticated sender: krisman) with ESMTPSA id 2B0B91F4545D From: Gabriel Krisman Bertazi To: Paul Lawrence Cc: Jeff Dike , Richard Weinberger , Anton Ivanov , Christopher Obbard , linux-um@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] um: ubd: Fix crash from option parsing Organization: Collabora References: <20210119181945.2071053-1-paullawrence@google.com> Date: Tue, 19 Jan 2021 15:35:35 -0300 In-Reply-To: <20210119181945.2071053-1-paullawrence@google.com> (Paul Lawrence's message of "Tue, 19 Jan 2021 18:19:45 +0000") Message-ID: <871regg4g8.fsf@collabora.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/27.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Paul Lawrence writes: > Below patch will cause NULL ptr dereferences if the optional filenames > are not present. > > Fixes: ef3ba87cb7c9 (um: ubd: Set device serial attribute from cmdline) > Signed-off-by: Paul Lawrence Looks good. Reviewed-by: Gabriel Krisman Bertazi Totally unrelated, but it seems the original patch writes a "(null)" string to the sysfs attribute, if no serial is defined. I think we should have a default serial UBDX in case the user didn't provide any. Thanks, > --- > arch/um/drivers/ubd_kern.c | 6 +++--- > 1 file changed, 3 insertions(+), 3 deletions(-) > > diff --git a/arch/um/drivers/ubd_kern.c b/arch/um/drivers/ubd_kern.c > index 13b1fe694b90..704989088f28 100644 > --- a/arch/um/drivers/ubd_kern.c > +++ b/arch/um/drivers/ubd_kern.c > @@ -371,15 +371,15 @@ static int ubd_setup_common(char *str, int *index_out, char **error_out) > > break_loop: > file = strsep(&str, ",:"); > - if (*file == '\0') > + if (file && *file == '\0') > file = NULL; > > backing_file = strsep(&str, ",:"); > - if (*backing_file == '\0') > + if (backing_file && *backing_file == '\0') > backing_file = NULL; > > serial = strsep(&str, ",:"); > - if (*serial == '\0') > + if (serial && *serial == '\0') > serial = NULL; > > if (backing_file && ubd_dev->no_cow) { -- Gabriel Krisman Bertazi