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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 A77E7C2D0DB for ; Tue, 28 Jan 2020 14:02:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7EE742468A for ; Tue, 28 Jan 2020 14:02:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1580220151; bh=uGwb690XcRRYmpaqN7R+SY+vxZZ7BfejGQQVQBgtTfQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=fGJZ1NseIt989yt10iU7T50B7LG6TRoiz8T5zseXxn3++OuJI6azgQIGyU6N+Mgd4 Myr65+nsrRMr7lAWljTJO2BWkXK5N5kQ3qzNsoaRANxOHQr3G2MCm4eCvB1xCtLgm0 cOdW4v8Ul+Tyc3rYdhsUa7F/txj/LwJqHbLS6PvQ= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727646AbgA1OCb (ORCPT ); Tue, 28 Jan 2020 09:02:31 -0500 Received: from mail.kernel.org ([198.145.29.99]:48742 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727630AbgA1OC1 (ORCPT ); Tue, 28 Jan 2020 09:02:27 -0500 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 0608524685; Tue, 28 Jan 2020 14:02:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1580220146; bh=uGwb690XcRRYmpaqN7R+SY+vxZZ7BfejGQQVQBgtTfQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=oydVqWlBEfGwInEifuzETK0OFPCzbSy7SaCmco6kK4ME/92ZGrXROCDoUvN5qL+43 9Rfh2FY6loUUUEB7VtYLLDxxkh8GgSIjQqwkOq283ih/qNbI4PBZacKKsnppfkYQku XLtDk4ZIYsN+UZxGqJCJfd6MSblA1VYIDiSmJBpI= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, syzbot+b904ba7c947a37b4b291@syzkaller.appspotmail.com, stable@kernel.org, David Howells , Linus Torvalds Subject: [PATCH 5.4 034/104] afs: Fix characters allowed into cell names Date: Tue, 28 Jan 2020 14:59:55 +0100 Message-Id: <20200128135822.012551775@linuxfoundation.org> X-Mailer: git-send-email 2.25.0 In-Reply-To: <20200128135817.238524998@linuxfoundation.org> References: <20200128135817.238524998@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: David Howells commit a45ea48e2bcd92c1f678b794f488ca0bda9835b8 upstream. The afs filesystem needs to prohibit certain characters from cell names, such as '/', as these are used to form filenames in procfs, leading to the following warning being generated: WARNING: CPU: 0 PID: 3489 at fs/proc/generic.c:178 Fix afs_alloc_cell() to disallow nonprintable characters, '/', '@' and names that begin with a dot. Remove the check for "@cell" as that is then redundant. This can be tested by running: echo add foo/.bar 1.2.3.4 >/proc/fs/afs/cells Note that we will also need to deal with: - Names ending in ".invalid" shouldn't be passed to the DNS. - Names that contain non-valid domainname chars shouldn't be passed to the DNS. - DNS replies that say "your-dns-needs-immediate-attention." and replies containing A records that say 127.0.53.53 should be considered invalid. [https://www.icann.org/en/system/files/files/name-collision-mitigation-01aug14-en.pdf] but these need to be dealt with by the kafs-client DNS program rather than the kernel. Reported-by: syzbot+b904ba7c947a37b4b291@syzkaller.appspotmail.com Cc: stable@kernel.org Signed-off-by: David Howells Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- fs/afs/cell.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) --- a/fs/afs/cell.c +++ b/fs/afs/cell.c @@ -134,8 +134,17 @@ static struct afs_cell *afs_alloc_cell(s _leave(" = -ENAMETOOLONG"); return ERR_PTR(-ENAMETOOLONG); } - if (namelen == 5 && memcmp(name, "@cell", 5) == 0) + + /* Prohibit cell names that contain unprintable chars, '/' and '@' or + * that begin with a dot. This also precludes "@cell". + */ + if (name[0] == '.') return ERR_PTR(-EINVAL); + for (i = 0; i < namelen; i++) { + char ch = name[i]; + if (!isprint(ch) || ch == '/' || ch == '@') + return ERR_PTR(-EINVAL); + } _enter("%*.*s,%s", namelen, namelen, name, addresses);