From patchwork Thu May 20 09:22:04 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 444390 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=-19.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, 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 E42D6C43462 for ; Thu, 20 May 2021 10:09:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CFC2161D6A for ; Thu, 20 May 2021 10:09:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235348AbhETKKx (ORCPT ); Thu, 20 May 2021 06:10:53 -0400 Received: from mail.kernel.org ([198.145.29.99]:43768 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235460AbhETKIv (ORCPT ); Thu, 20 May 2021 06:08:51 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 643256143A; Thu, 20 May 2021 09:42:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1621503734; bh=e0XjMLk829S1IqiWdREGCSZM0P1bCu+NXQbESvhWf4g=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Qo6C9SrFqN5R17vn8DH1L5nCO+rEi7LIPavVtWjXDg+DRHa2gMErWx66WRjjifYMe 1uF+ygkHOCASx1E8ukh3hKFQFiCDnS/nQxwMTqDSUq8khhHJOODk0XnNLeiW1ilbqh f0OOVl1MYYQcKEqTuvmjJ0l/xC4/YttkokpPjExI= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Nucca Chen , Cong Wang , David Ahern , "David S. Miller" , Jakub Kicinski , Jamal Hadi Salim , Jiri Pirko , Jiri Pirko , Sasha Levin Subject: [PATCH 4.19 355/425] net: fix nla_strcmp to handle more then one trailing null character Date: Thu, 20 May 2021 11:22:04 +0200 Message-Id: <20210520092143.076689129@linuxfoundation.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210520092131.308959589@linuxfoundation.org> References: <20210520092131.308959589@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Maciej Żenczykowski [ Upstream commit 2c16db6c92b0ee4aa61e88366df82169e83c3f7e ] Android userspace has been using TCA_KIND with a char[IFNAMESIZ] many-null-terminated buffer containing the string 'bpf'. This works on 4.19 and ceases to work on 5.10. I'm not entirely sure what fixes tag to use, but I think the issue was likely introduced in the below mentioned 5.4 commit. Reported-by: Nucca Chen Cc: Cong Wang Cc: David Ahern Cc: David S. Miller Cc: Jakub Kicinski Cc: Jamal Hadi Salim Cc: Jiri Pirko Cc: Jiri Pirko Fixes: 62794fc4fbf5 ("net_sched: add max len check for TCA_KIND") Change-Id: I66dc281f165a2858fc29a44869a270a2d698a82b Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- lib/nlattr.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/lib/nlattr.c b/lib/nlattr.c index e335bcafa9e4..00bfc6aece05 100644 --- a/lib/nlattr.c +++ b/lib/nlattr.c @@ -402,7 +402,7 @@ int nla_strcmp(const struct nlattr *nla, const char *str) int attrlen = nla_len(nla); int d; - if (attrlen > 0 && buf[attrlen - 1] == '\0') + while (attrlen > 0 && buf[attrlen - 1] == '\0') attrlen--; d = attrlen - len;