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 X-Spam-Level: X-Spam-Status: No, score=-5.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 911BBC38A30 for ; Wed, 22 Apr 2020 06:42:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6EBC8206E9 for ; Wed, 22 Apr 2020 06:42:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726575AbgDVGmc (ORCPT ); Wed, 22 Apr 2020 02:42:32 -0400 Received: from nautica.notk.org ([91.121.71.147]:38194 "EHLO nautica.notk.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726077AbgDVGmc (ORCPT ); Wed, 22 Apr 2020 02:42:32 -0400 Received: by nautica.notk.org (Postfix, from userid 1001) id 493BBC009; Wed, 22 Apr 2020 08:42:30 +0200 (CEST) Date: Wed, 22 Apr 2020 08:42:15 +0200 From: Dominique Martinet To: Jamal Hadi Salim Cc: stephen@networkplumber.org, netdev@vger.kernel.org, dsahern@gmail.com, aclaudi@redhat.com, daniel@iogearbox.net, Jamal Hadi Salim Subject: Re: [PATCH iproute2 1/1] bpf: Fix segfault when custom pinning is used Message-ID: <20200422064215.GA17201@nautica> References: <20200421180426.6945-1-jhs@emojatatu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20200421180426.6945-1-jhs@emojatatu.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org (random review) Jamal Hadi Salim wrote on Tue, Apr 21, 2020: > diff --git a/lib/bpf.c b/lib/bpf.c > index 10cf9bf4..cf636c9e 100644 > --- a/lib/bpf.c > +++ b/lib/bpf.c > @@ -1509,12 +1509,12 @@ out: > static int bpf_make_custom_path(const struct bpf_elf_ctx *ctx, > const char *todo) > { > - char *tmp = NULL; > + char tmp[PATH_MAX] = {}; > char *rem = NULL; > char *sub; > int ret; > > - ret = asprintf(&tmp, "%s/../", bpf_get_work_dir(ctx->type)); > + ret = sprintf(tmp, "%s/../", bpf_get_work_dir(ctx->type)); > if (ret < 0) { > fprintf(stderr, "asprintf failed: %s\n", strerror(errno)); error check needs to be reworded, and it probably needs to use snprintf instead of sprintf: bpf_get_work_dir() can be up to PATH_MAX long and as pointed out there are strcat() afterwards so it's still possible to overflow this one -- Dominique