From patchwork Thu May 16 18:18:27 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Florian Weimer X-Patchwork-Id: 1100695 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=sourceware.org (client-ip=209.132.180.131; helo=sourceware.org; envelope-from=libc-alpha-return-102038-incoming=patchwork.ozlabs.org@sourceware.org; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: ozlabs.org; dkim=pass (1024-bit key; secure) header.d=sourceware.org header.i=@sourceware.org header.b="Zv2bv3zo"; dkim-atps=neutral Received: from sourceware.org (server1.sourceware.org [209.132.180.131]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 454fn95fPCz9s9N for ; Fri, 17 May 2019 04:18:37 +1000 (AEST) DomainKey-Signature: a=rsa-sha1; c=nofws; d=sourceware.org; h=list-id :list-unsubscribe:list-subscribe:list-archive:list-post :list-help:sender:from:to:subject:date:message-id:mime-version :content-type; q=dns; s=default; b=NB0lPDE2NHaEn3EYRemXkz+9Ggl7e QJjiPnIVJpxd60jORxmmtT05GFn0BLbKIO/R6HKf442sWSK0f7Xk/e6Vp1yLsx// NOfpnbeK0/my0wIJPkNbiB+3IWDcL0COGkhLutmWLeEe3QFT8vL9hGFvx8KVcKtf Rs9mgK0uJ+EHWs= DKIM-Signature: v=1; a=rsa-sha1; c=relaxed; d=sourceware.org; h=list-id :list-unsubscribe:list-subscribe:list-archive:list-post :list-help:sender:from:to:subject:date:message-id:mime-version :content-type; s=default; bh=AayuejJMBs1ei0mIXkJdwAhQYKY=; b=Zv2 bv3zo9nBidY93pDAjhIenVhUAyk5hB4YvfBBQBH5O8bS5bVXtdRhdsIhfadhYQ5Y zhTNaNUAD+OXcm0Hxo/a6oP7T5ZzQcdPSERCrSRvSM9Jq+e6ljD+5H3jh3Q3PkjU KCt5aV/nuJ1Oyw4xnpkgM+AIkn1UgkLUipxusg+M= Received: (qmail 82600 invoked by alias); 16 May 2019 18:18:32 -0000 Mailing-List: contact libc-alpha-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Unsubscribe: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: libc-alpha-owner@sourceware.org Delivered-To: mailing list libc-alpha@sourceware.org Received: (qmail 82592 invoked by uid 89); 16 May 2019 18:18:31 -0000 Authentication-Results: sourceware.org; auth=none X-Spam-SWARE-Status: No, score=-19.1 required=5.0 tests=AWL, BAYES_00, GIT_PATCH_0, GIT_PATCH_1, GIT_PATCH_2, GIT_PATCH_3, SPF_HELO_PASS autolearn=ham version=3.3.1 spammy=HX-Languages-Length:1011 X-HELO: mx1.redhat.com From: Florian Weimer To: libc-alpha@sourceware.org Subject: [PATCH] nss_dns: Check for proper A/AAAA address alignment Date: Thu, 16 May 2019 20:18:27 +0200 Message-ID: <87imuas1os.fsf@oldenburg2.str.redhat.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.1 (gnu/linux) MIME-Version: 1.0 2019-05-16 Florian Weimer * resolv/nss_dns/dns-host.c (getanswer_r): Be more explicit about struct in_addr/struct in6_addr alignment. Reviewed-by: Carlos O'Donell diff --git a/resolv/nss_dns/dns-host.c b/resolv/nss_dns/dns-host.c index 9c15f25f28..9c40051aff 100644 --- a/resolv/nss_dns/dns-host.c +++ b/resolv/nss_dns/dns-host.c @@ -947,8 +947,15 @@ getanswer_r (struct resolv_context *ctx, linebuflen -= nn; } - linebuflen -= sizeof (align) - ((u_long) bp % sizeof (align)); - bp += sizeof (align) - ((u_long) bp % sizeof (align)); + /* Provide sufficient alignment for both address + families. */ + enum { align = 4 }; + _Static_assert ((align % __alignof__ (struct in_addr)) == 0, + "struct in_addr alignment"); + _Static_assert ((align % __alignof__ (struct in6_addr)) == 0, + "struct in6_addr alignment"); + linebuflen -= align - ((u_long) bp % align); + bp += align - ((u_long) bp % align); if (__glibc_unlikely (n > linebuflen)) goto too_small;