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 Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 4FF36C3DA7F for ; Wed, 7 Aug 2024 18:50:20 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1sbljL-0001pI-89; Wed, 07 Aug 2024 14:49:51 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1sbljJ-0001nL-1u for qemu-devel@nongnu.org; Wed, 07 Aug 2024 14:49:49 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1sbljH-0000d0-31 for qemu-devel@nongnu.org; Wed, 07 Aug 2024 14:49:48 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1723056581; h=from:from:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=Njo5QMsccRYfU9sZCJh4Xok9zz4eMQXc10FOs/J8wp0=; b=dLUKSlExEPnCZaDopo5vKY04g+8QggyD96IjKC6n++JM04NikSaWCBi7mfp0KAl7l5uMo1 tAFt9+eobb20m0ZqJwQw7dcIxgQFwgO20aBlLw0Jhw/+oRAg+btozLkspMSDsAl3Y9DN4l HPHmReVFMl/r3NboDTYBQJ5O8hUYfl0= Received: from mx-prod-mc-01.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-442-703nJ7luN0ex3BLy5ox0UQ-1; Wed, 07 Aug 2024 14:49:38 -0400 X-MC-Unique: 703nJ7luN0ex3BLy5ox0UQ-1 Received: from mx-prod-int-04.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-04.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.40]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-01.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id A199519560A2; Wed, 7 Aug 2024 18:49:37 +0000 (UTC) Received: from redhat.com (unknown [10.42.28.79]) by mx-prod-int-04.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 2D89119560AE; Wed, 7 Aug 2024 18:49:35 +0000 (UTC) Date: Wed, 7 Aug 2024 19:49:32 +0100 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: Eric Blake Cc: qemu-devel@nongnu.org, qemu-block@nongnu.org, rjones@redhat.com, Markus Armbruster Subject: Re: [PATCH 1/2] util: Refactor json-writer's string sanitizer to be public Message-ID: References: <20240802194156.2131519-4-eblake@redhat.com> <20240802194156.2131519-5-eblake@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20240802194156.2131519-5-eblake@redhat.com> User-Agent: Mutt/2.2.12 (2023-09-09) X-Scanned-By: MIMEDefang 3.0 on 10.30.177.40 Received-SPF: pass client-ip=170.10.133.124; envelope-from=berrange@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -21 X-Spam_score: -2.2 X-Spam_bar: -- X-Spam_report: (-2.2 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.144, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On Fri, Aug 02, 2024 at 02:26:05PM -0500, Eric Blake wrote: > My next patch needs to convert text from an untrusted input into an > output representation that is suitable for display on a terminal is > useful to more than just the json-writer; the text should normally be > UTF-8, but blindly allowing all Unicode code points (including ASCII > ESC) through to a terminal risks remote-code-execution attacks on some > terminals. Extract the existing body of json-writer's quoted_strinto > a new helper routine mod_utf8_sanitize, and generalize it to also work > on data that is length-limited rather than NUL-terminated. [I was > actually surprised that glib does not have such a sanitizer already - > Google turns up lots of examples of rolling your own string > sanitizer.] > > If desired in the future, we may want to tweak whether the output is > guaranteed to be ASCII (using lots of \u escape sequences, including > surrogate pairs for code points outside the BMP) or if we are okay > passing printable Unicode through (we still need to escape control > characters). But for now, I went for minimal code churn, including > the fact that the resulting function allows a non-UTF-8 2-byte synonym > for U+0000. > > Signed-off-by: Eric Blake > --- > include/qemu/unicode.h | 3 ++ > qobject/json-writer.c | 47 +---------------------- > util/unicode.c | 84 ++++++++++++++++++++++++++++++++++++++++++ > 3 files changed, 88 insertions(+), 46 deletions(-) I was going to ask for a unit test, but "escaped_string" in test-qjson.c looks like it will be covering this sufficiently well already, that we don't need to test it in isolation. Reviewed-by: Daniel P. Berrangé With regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|