From owner-svn-src-all@FreeBSD.ORG Fri Feb 21 03:36:17 2014 Return-Path: Delivered-To: svn-src-all@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 8E915667; Fri, 21 Feb 2014 03:36:17 +0000 (UTC) Received: from svn.freebsd.org (svn.freebsd.org [IPv6:2001:1900:2254:2068::e6a:0]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx1.freebsd.org (Postfix) with ESMTPS id 74577180B; Fri, 21 Feb 2014 03:36:17 +0000 (UTC) Received: from svn.freebsd.org ([127.0.1.70]) by svn.freebsd.org (8.14.8/8.14.8) with ESMTP id s1L3aHPf016406; Fri, 21 Feb 2014 03:36:17 GMT (envelope-from davidxu@svn.freebsd.org) Received: (from davidxu@localhost) by svn.freebsd.org (8.14.8/8.14.8/Submit) id s1L3aHBG016405; Fri, 21 Feb 2014 03:36:17 GMT (envelope-from davidxu@svn.freebsd.org) Message-Id: <201402210336.s1L3aHBG016405@svn.freebsd.org> From: David Xu Date: Fri, 21 Feb 2014 03:36:17 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r262277 - head/libexec/rtld-elf X-SVN-Group: head MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-BeenThere: svn-src-all@freebsd.org X-Mailman-Version: 2.1.17 Precedence: list List-Id: "SVN commit messages for the entire src tree \(except for " user" and " projects" \)" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 21 Feb 2014 03:36:17 -0000 Author: davidxu Date: Fri Feb 21 03:36:16 2014 New Revision: 262277 URL: http://svnweb.freebsd.org/changeset/base/262277 Log: malloc_aligned() may not leave enough space for pointer to allocated memory, saving the pointer will overwrite bytes belongs to another memory block unexpectly, to fix the problem, use (allocated address + sizeof(void *)) as initial value, and slip to next aligned address, so maximum extra bytes is sizeof(void *) + align - 1. Tested by: Andre Albsmeier < mail at ma17 dot ata dot myota dot orgndre > Modified: head/libexec/rtld-elf/xmalloc.c Modified: head/libexec/rtld-elf/xmalloc.c ============================================================================== --- head/libexec/rtld-elf/xmalloc.c Fri Feb 21 03:35:43 2014 (r262276) +++ head/libexec/rtld-elf/xmalloc.c Fri Feb 21 03:36:16 2014 (r262277) @@ -72,14 +72,14 @@ void * malloc_aligned(size_t size, size_t align) { void *mem, *res; - uintptr_t x; - size_t asize, r; - r = round(sizeof(void *), align); - asize = round(size, align) + r; - mem = xmalloc(asize); - x = (uintptr_t)mem; - res = (void *)round(x, align); + if (align & (sizeof(void *) -1)) { + rtld_fdputstr(STDERR_FILENO, "Invalid alignment\n"); + _exit(1); + } + + mem = xmalloc(size + sizeof(void *) + align - 1); + res = (void *)round((uintptr_t)mem + sizeof(void *), align); *(void **)((uintptr_t)res - sizeof(void *)) = mem; return (res); }