From patchwork Wed Nov 3 17:32:09 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrii Nakryiko X-Patchwork-Id: 12601349 X-Patchwork-Delegate: bpf@iogearbox.net 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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id BF9A9C433EF for ; Wed, 3 Nov 2021 17:35:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9FFFD61108 for ; Wed, 3 Nov 2021 17:35:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229621AbhKCRhf convert rfc822-to-8bit (ORCPT ); Wed, 3 Nov 2021 13:37:35 -0400 Received: from mx0a-00082601.pphosted.com ([67.231.145.42]:31016 "EHLO mx0a-00082601.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229780AbhKCRhd (ORCPT ); Wed, 3 Nov 2021 13:37:33 -0400 Received: from pps.filterd (m0148461.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.16.1.2/8.16.1.2) with SMTP id 1A3H6163010062 for ; Wed, 3 Nov 2021 10:34:56 -0700 Received: from mail.thefacebook.com ([163.114.132.120]) by mx0a-00082601.pphosted.com with ESMTP id 3c3dch6v4p-2 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Wed, 03 Nov 2021 10:34:56 -0700 Received: from intmgw002.46.prn1.facebook.com (2620:10d:c085:208::f) by mail.thefacebook.com (2620:10d:c085:21d::6) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.14; Wed, 3 Nov 2021 10:34:55 -0700 Received: by devbig019.vll3.facebook.com (Postfix, from userid 137359) id 6D4017D16076; Wed, 3 Nov 2021 10:32:22 -0700 (PDT) From: Andrii Nakryiko To: , , CC: , , Yonghong Song Subject: [PATCH v2 bpf-next 1/5] libbpf: detect corrupted ELF symbols section Date: Wed, 3 Nov 2021 10:32:09 -0700 Message-ID: <20211103173213.1376990-2-andrii@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20211103173213.1376990-1-andrii@kernel.org> References: <20211103173213.1376990-1-andrii@kernel.org> MIME-Version: 1.0 X-FB-Internal: Safe X-FB-Source: Intern X-Proofpoint-GUID: a9IFksI7qu8m5Q40eemzDpYPcX1lJhaU X-Proofpoint-ORIG-GUID: a9IFksI7qu8m5Q40eemzDpYPcX1lJhaU X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.205,Aquarius:18.0.790,Hydra:6.0.425,FMLib:17.0.607.475 definitions=2021-11-03_06,2021-11-03_01,2020-04-07_01 X-Proofpoint-Spam-Details: rule=fb_default_notspam policy=fb_default score=0 spamscore=0 bulkscore=0 clxscore=1034 lowpriorityscore=0 priorityscore=1501 phishscore=0 mlxlogscore=856 impostorscore=0 malwarescore=0 suspectscore=0 mlxscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2110150000 definitions=main-2111030094 X-FB-Internal: deliver Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net Prevent divide-by-zero if ELF is corrupted and has zero sh_entsize. Reported by oss-fuzz project. Acked-by: Yonghong Song Signed-off-by: Andrii Nakryiko --- tools/lib/bpf/libbpf.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index a1bea1953df6..71f5a009010a 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -3555,7 +3555,7 @@ static int bpf_object__collect_externs(struct bpf_object *obj) scn = elf_sec_by_idx(obj, obj->efile.symbols_shndx); sh = elf_sec_hdr(obj, scn); - if (!sh) + if (!sh || sh->sh_entsize != sizeof(Elf64_Sym)) return -LIBBPF_ERRNO__FORMAT; dummy_var_btf_id = add_dummy_ksym_var(obj->btf);