From patchwork Mon Dec 14 13:25:01 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Michal Kubecek X-Patchwork-Id: 343853 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=-13.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED 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 1AD62C1B0E3 for ; Mon, 14 Dec 2020 13:26:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C1EB4224DF for ; Mon, 14 Dec 2020 13:26:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2439479AbgLNN0K (ORCPT ); Mon, 14 Dec 2020 08:26:10 -0500 Received: from mx2.suse.de ([195.135.220.15]:52356 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2439357AbgLNNZt (ORCPT ); Mon, 14 Dec 2020 08:25:49 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 7F87AAC10; Mon, 14 Dec 2020 13:25:01 +0000 (UTC) Received: by lion.mk-sys.cz (Postfix, from userid 1000) id 1346B6030D; Mon, 14 Dec 2020 14:25:01 +0100 (CET) Message-Id: From: Michal Kubecek Subject: [PATCH net] ethtool: fix string set id check To: "David S. Miller" , Jakub Kicinski , netdev@vger.kernel.org Cc: linux-kernel@vger.kernel.org Date: Mon, 14 Dec 2020 14:25:01 +0100 (CET) Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Syzbot reported a shift of a u32 by more than 31 in strset_parse_request() which is undefined behavior. This is caused by range check of string set id using variable ret (which is always 0 at this point) instead of id (string set id from request). Fixes: 71921690f974 ("ethtool: provide string sets with STRSET_GET request") Reported-by: syzbot+96523fb438937cd01220@syzkaller.appspotmail.com Signed-off-by: Michal Kubecek --- net/ethtool/strset.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/ethtool/strset.c b/net/ethtool/strset.c index 0baad0ce1832..c3a5489964cd 100644 --- a/net/ethtool/strset.c +++ b/net/ethtool/strset.c @@ -182,7 +182,7 @@ static int strset_parse_request(struct ethnl_req_info *req_base, ret = strset_get_id(attr, &id, extack); if (ret < 0) return ret; - if (ret >= ETH_SS_COUNT) { + if (id >= ETH_SS_COUNT) { NL_SET_ERR_MSG_ATTR(extack, attr, "unknown string set id"); return -EOPNOTSUPP;