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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 15E42C3DA7D for ; Wed, 28 Dec 2022 15:20:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233306AbiL1PUp (ORCPT ); Wed, 28 Dec 2022 10:20:45 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39732 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233406AbiL1PUo (ORCPT ); Wed, 28 Dec 2022 10:20:44 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E34B02B0 for ; Wed, 28 Dec 2022 07:20:42 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 7E08A6154D for ; Wed, 28 Dec 2022 15:20:42 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8FB7EC433EF; Wed, 28 Dec 2022 15:20:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1672240841; bh=umQvhBBzdgHAHwKfETrU2v5wTEeoGD+YwX7xEgNvcz0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=yKKpCv9ptNDaGI69tedFYFIO9PxcnZIDmy87jc2WJ6JTxemepCwJTHiiZ/lFH/iWW Llmq9WOSe8/HhZ5maar6rFfPGHkIgF30cyUflCOC7PjzuNlBOMSWULFEeRRouz0H3D MCQ2Ej/6jWFO7dky6lQ1RCMX0jD+uec1juxGXW20= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Shung-Hsi Yu , Andrii Nakryiko , Sasha Levin Subject: [PATCH 6.0 0209/1073] libbpf: Fix null-pointer dereference in find_prog_by_sec_insn() Date: Wed, 28 Dec 2022 15:29:57 +0100 Message-Id: <20221228144333.696602741@linuxfoundation.org> X-Mailer: git-send-email 2.39.0 In-Reply-To: <20221228144328.162723588@linuxfoundation.org> References: <20221228144328.162723588@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Shung-Hsi Yu [ Upstream commit d0d382f95a9270dcf803539d6781d6bd67e3f5b2 ] When there are no program sections, obj->programs is left unallocated, and find_prog_by_sec_insn()'s search lands on &obj->programs[0] == NULL, and will cause null-pointer dereference in the following access to prog->sec_idx. Guard the search with obj->nr_programs similar to what's being done in __bpf_program__iter() to prevent null-pointer access from happening. Fixes: db2b8b06423c ("libbpf: Support CO-RE relocations for multi-prog sections") Signed-off-by: Shung-Hsi Yu Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20221012022353.7350-4-shung-hsi.yu@suse.com Signed-off-by: Sasha Levin --- tools/lib/bpf/libbpf.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 5561b23338a7..c01f57d31f89 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -4085,6 +4085,9 @@ static struct bpf_program *find_prog_by_sec_insn(const struct bpf_object *obj, int l = 0, r = obj->nr_programs - 1, m; struct bpf_program *prog; + if (!obj->nr_programs) + return NULL; + while (l < r) { m = l + (r - l + 1) / 2; prog = &obj->programs[m]; -- 2.35.1