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 1A110C3DA4A for ; Thu, 8 Aug 2024 07:57:43 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1sby1O-0006xN-Uw; Thu, 08 Aug 2024 03:57:19 -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 1sby1K-0006sw-TM for qemu-devel@nongnu.org; Thu, 08 Aug 2024 03:57:15 -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 1sby1J-0008Ia-CV for qemu-devel@nongnu.org; Thu, 08 Aug 2024 03:57:14 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1723103832; h=from:from: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=IGVQaPpa4MM416kbevD3IjdsqVCxTJKzpbhOlw6/CHo=; b=hfCDWFEKH8213Ezm9ns06/FLAYFNdbLTpF8uvkfEVJlOWxQGJNq6e8d2dqCqqEgll6klPK 2eo45PrYmQn2BN2GCQRys5B4+2g8xZrjuxA9p6T2asvlQKDyzylzp1pvXcWQs5WyJ1vyO6 yyhbD1j0/PygjsgWfuDwWHHyjIU1ylc= 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-624-yCB0IX6xNwesfwhMC90u-Q-1; Thu, 08 Aug 2024 03:57:08 -0400 X-MC-Unique: yCB0IX6xNwesfwhMC90u-Q-1 Received: from mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.12]) (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 DDE431935D11; Thu, 8 Aug 2024 07:57:07 +0000 (UTC) Received: from blackfin.pond.sub.org (unknown [10.39.193.245]) by mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 850E41955F2E; Thu, 8 Aug 2024 07:57:06 +0000 (UTC) Received: by blackfin.pond.sub.org (Postfix, from userid 1000) id 0447221E6692; Thu, 8 Aug 2024 09:57:04 +0200 (CEST) From: Markus Armbruster To: Daniel P. =?utf-8?Q?Berrang=C3=A9?= Cc: Eric Blake , qemu-devel@nongnu.org, qemu-block@nongnu.org, rjones@redhat.com Subject: Re: [PATCH 1/2] util: Refactor json-writer's string sanitizer to be public In-Reply-To: ("Daniel P. =?utf-8?Q?Berrang?= =?utf-8?Q?=C3=A9=22's?= message of "Wed, 7 Aug 2024 19:49:32 +0100") References: <20240802194156.2131519-4-eblake@redhat.com> <20240802194156.2131519-5-eblake@redhat.com> Date: Thu, 08 Aug 2024 09:57:03 +0200 Message-ID: <87a5hn4fcg.fsf@pond.sub.org> User-Agent: Gnus/5.13 (Gnus v5.13) MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-Scanned-By: MIMEDefang 3.0 on 10.30.177.12 Received-SPF: pass client-ip=170.10.133.124; envelope-from=armbru@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=unavailable 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: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Daniel P. Berrang=C3=A9 writes: > 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.] >>=20 >> 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. >>=20 >> 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 check-qjson.c, and other test cases torture it some more. > well already, that we don't need to test it in isolation. > > Reviewed-by: Daniel P. Berrang=C3=A9 > > > With regards, > Daniel