From patchwork Mon Aug 10 15:20:50 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 266610 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=-13.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT autolearn=unavailable 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 622B3C433DF for ; Mon, 10 Aug 2020 15:41:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3CBFB20825 for ; Mon, 10 Aug 2020 15:41:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597074084; bh=3RsfUAp7aGDaL2Wks05J/+SuJ3XwH3Ysi/8Wj7A4IOY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=Fu1TpD8Zzl6uQIamU7L4emmGQrmCwPMQVOz3qICZp+6/kCRBod6HNV+1JAnFGN53e 9Yx4zHkqDpZ5b0NIAIwSTh2P6eEan8Mot7Ore5Ap7BvU22c0vHR/SXj0vLnSQCY5AM HoFGndRrAhhTxUO5Xx3V/iRMffRoQ/ufoaJv8zUg= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728334AbgHJPlS (ORCPT ); Mon, 10 Aug 2020 11:41:18 -0400 Received: from mail.kernel.org ([198.145.29.99]:54540 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727880AbgHJPXT (ORCPT ); Mon, 10 Aug 2020 11:23:19 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id A0CF2207FF; Mon, 10 Aug 2020 15:23:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597072999; bh=3RsfUAp7aGDaL2Wks05J/+SuJ3XwH3Ysi/8Wj7A4IOY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=B4J2aNCFwnkhgiNEEDAJbJ7i1OWXIyqMpPyHCjpELRBj76oj561IONCFuvAypoteN DzsTV1doUt2/JNRL4PZUmSjXp7l+XpmyxqFNCRf/mg1jrPuSF2n3gZY17RQInLg6dm lZMDLefVzRZcZN7VNOuGW+1PlOWZMxVA8Nd4KZns= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, syzbot+ee09bda7017345f1fbe6@syzkaller.appspotmail.com, Peilin Ye , Daniel Borkmann , Sasha Levin Subject: [PATCH 5.7 31/79] bpf: Fix NULL pointer dereference in __btf_resolve_helper_id() Date: Mon, 10 Aug 2020 17:20:50 +0200 Message-Id: <20200810151813.824095381@linuxfoundation.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200810151812.114485777@linuxfoundation.org> References: <20200810151812.114485777@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Peilin Ye [ Upstream commit 5b801dfb7feb2738975d80223efc2fc193e55573 ] Prevent __btf_resolve_helper_id() from dereferencing `btf_vmlinux` as NULL. This patch fixes the following syzbot bug: https://syzkaller.appspot.com/bug?id=f823224ada908fa5c207902a5a62065e53ca0fcc Reported-by: syzbot+ee09bda7017345f1fbe6@syzkaller.appspotmail.com Signed-off-by: Peilin Ye Signed-off-by: Daniel Borkmann Link: https://lore.kernel.org/bpf/20200714180904.277512-1-yepeilin.cs@gmail.com Signed-off-by: Sasha Levin --- kernel/bpf/btf.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c index d1f5d428c9fe2..6cafc596631c3 100644 --- a/kernel/bpf/btf.c +++ b/kernel/bpf/btf.c @@ -4011,6 +4011,11 @@ static int __btf_resolve_helper_id(struct bpf_verifier_log *log, void *fn, const char *tname, *sym; u32 btf_id, i; + if (!btf_vmlinux) { + bpf_log(log, "btf_vmlinux doesn't exist\n"); + return -EINVAL; + } + if (IS_ERR(btf_vmlinux)) { bpf_log(log, "btf_vmlinux is malformed\n"); return -EINVAL;