From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by sourceware.org (Postfix) with ESMTPS id E447A3858D37 for ; Thu, 30 Nov 2023 11:58:41 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org E447A3858D37 Authentication-Results: sourceware.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=redhat.com ARC-Filter: OpenARC Filter v1.0.0 sourceware.org E447A3858D37 Authentication-Results: server2.sourceware.org; arc=none smtp.remote-ip=170.10.129.124 ARC-Seal: i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1701345523; cv=none; b=cOR1jjD+RNpyHNxjr4v3mqvY7+vEkPgMa/EKKnYhxVigRVDAvnB0SDKbJmj8m3kr+BCardCcqxzMM3DUNMjs2YfnwHqTH/StoZ7YWuqrdFBTSu5FN0QCltfrMlNdKdWERQyWsIY2zLbn/sgImJD+xecSFQz1R9T9/mniLWqpMcY= ARC-Message-Signature: i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1701345523; c=relaxed/simple; bh=zhgib9lRwut8bhyRUZknsIzi85Y40MAzowotbm5oDEE=; h=DKIM-Signature:From:To:Subject:Date:Message-ID:MIME-Version; b=nNGkFxEflRWrlwPeH+4szdMVw9W1T1tv6PQJn3Dn2rqi5On3XL6VRrC+ayxTtMGGsHHS9xWBYmCTJXgjdd0DrIWI3FYFwSkatB1PbvYAq/x1tdDQ3vBcr/Y99S5ACaz6gK7jNHfRKL5FM5A+oAdgRxKtaDPvw+FeTBWNPRn6Mh4= ARC-Authentication-Results: i=1; server2.sourceware.org DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1701345521; 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: in-reply-to:in-reply-to:references:references; bh=fwl9Z8R3DrWWGn/S0Dsk6bgCirv2YmVxDSwzNdGFTrc=; b=gtfXSVm2RQbSAxpUC2kJOmPuza/F5rtaEK7/AB6j8zd10OtLytj+EzgqMpjzI6PQshFNKw qsmS90WJX7RBFZiIC1u8yyrLq25hvtHskjj/pN0bFoDu/wxzT6ESjeVrHV3olRX5E9gTXN IC3N31bfCcSW9UNL2YUIlzayeqUKads= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-483-zBokGftcOCuCTWmfxCoQVg-1; Thu, 30 Nov 2023 06:58:38 -0500 X-MC-Unique: zBokGftcOCuCTWmfxCoQVg-1 Received: from smtp.corp.redhat.com (int-mx10.intmail.prod.int.rdu2.redhat.com [10.11.54.10]) (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 mimecast-mx02.redhat.com (Postfix) with ESMTPS id D5168101FAA3; Thu, 30 Nov 2023 11:58:37 +0000 (UTC) Received: from oldenburg.str.redhat.com (unknown [10.2.16.45]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 5CB0B475046; Thu, 30 Nov 2023 11:58:37 +0000 (UTC) From: Florian Weimer To: amb via Libc-help Cc: amb Subject: Re: [Bug libc/23323] Recommendations for devs stuck with old glibc versions References: Date: Thu, 30 Nov 2023 12:58:35 +0100 In-Reply-To: (amb via Libc-help's message of "Thu, 30 Nov 2023 04:49:18 -0500") Message-ID: <87h6l3v4es.fsf@oldenburg.str.redhat.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/28.3 (gnu/linux) MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.10 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain X-Spam-Status: No, score=-4.6 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_NONE,RCVD_IN_MSPIKE_H4,RCVD_IN_MSPIKE_WL,SPF_HELO_NONE,SPF_NONE,TXREP,T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org List-Id: * amb via Libc-help: > I am forced to build against an old glibc version in order to run my > code on a large number of target linux systems. For developers like > me, what is the recommended way to mitigate the issue described in > https://sourceware.org/bugzilla/show_bug.cgi?id=23323 ? It's just a missed hardening opportunity. Your binary will likely have other gadgets in it anyway. Note that we have not treated it as a security vulnerability. If your main program does not use ELF constructors, you can use custom startup files without the ELF constructor trampoline. Thanks, Florian