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=-7.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=no 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 EF4CFC433B4 for ; Tue, 6 Apr 2021 13:16:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9CB9E613B7 for ; Tue, 6 Apr 2021 13:16:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242471AbhDFNQo (ORCPT ); Tue, 6 Apr 2021 09:16:44 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55488 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229720AbhDFNQl (ORCPT ); Tue, 6 Apr 2021 09:16:41 -0400 Received: from mail-lf1-x136.google.com (mail-lf1-x136.google.com [IPv6:2a00:1450:4864:20::136]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 435E9C06174A; Tue, 6 Apr 2021 06:16:33 -0700 (PDT) Received: by mail-lf1-x136.google.com with SMTP id n8so3922988lfh.1; Tue, 06 Apr 2021 06:16:33 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=message-id:subject:from:to:cc:date:in-reply-to:references :user-agent:mime-version:content-transfer-encoding; bh=oK0EvQq5supIkmdytebd79wfYwhuD8P3BwaCXG7Z7hI=; b=JwlFh059EWXARC3pWryr8G4rNFVgyPGcRFcZR3fc1UgSmW+vYxbhtLzBO+4CJ6B11T +nQxQB1ezl2f0aEoqMYI/rwPLzu5Iw9feXGZqkS5LCAUws+2QhLEZ8ORgEYpagBJqfsB sUq3rnvJbBNT08uEY+s8kNnzOmibxNNxrRxeIbXStWNmc5HIEJl0f/nfoRRgPFCD9tuK tYPDue4tqXb7ytfEbotfk6cbw98fMsYZtEItNYm+w5WNkHDKyHJu9dOsN8ZSSbN3tfo4 dVl8WfepjQsBc9LdtMpvvHqSfsP45sKKPoGOjBA1m0/rdBeyGGlm2pdKGF31XhEdG4Bf o0Ow== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:message-id:subject:from:to:cc:date:in-reply-to :references:user-agent:mime-version:content-transfer-encoding; bh=oK0EvQq5supIkmdytebd79wfYwhuD8P3BwaCXG7Z7hI=; b=jAJIluhf9XnmHn/r2DpWyVp9cZhWtV9WVphqmGL5BfBzV/7pRtBrHlnv7aGs/RDtjU eOb+uqlvF0/+YMu45ffTWxxGEIIc1jW5sRy1uI7BS+VO9Wr81Fr1pg7lhd2+0wIakqOS u5qpJJUAPFv3j01MBuUT3zIekrqbAr+QoTaPWOZsxJ7lJ75Fg0de5Tz2nxxjedGmsiO8 913G1kuY3pZxNSvqtmZAAWl3+DLQwN+D+dUqNv6CADiK18wibAON5gmI7QymzQXiQ7XJ zqCEg/w8fBVFruyz5hCO3kPw3oE82UJCDIPqilQQlznSEaqD1FJNGpVL6yRzIPMtfu+G xfxw== X-Gm-Message-State: AOAM533lP8HRiWEyByAalQL3fzKRbt0mgKLKMVTD3Q20eO+iqcDAzMGG nbV6+q7L50S40Lop6QhtRgyacp3nDsaEfL+E X-Google-Smtp-Source: ABdhPJzDhp+uGFjyYrbpEJDXoTUzaRZ6JV3//HVJvbSnqFgMDmHs32s/CEiY0zu/w/kQgWc+yhkd6A== X-Received: by 2002:a19:242:: with SMTP id 63mr3139544lfc.0.1617714991761; Tue, 06 Apr 2021 06:16:31 -0700 (PDT) Received: from [192.168.1.11] ([94.103.229.149]) by smtp.gmail.com with ESMTPSA id x27sm2158024lfn.95.2021.04.06.06.16.30 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 06 Apr 2021 06:16:31 -0700 (PDT) Message-ID: Subject: Re: [PATCH] net: fix shift-out-of-bounds in nl802154_new_interface From: Pavel Skripkin To: Alexander Aring Cc: Stefan Schmidt , "David S. Miller" , linux-wpan - ML , "open list:NETWORKING [GENERAL]" , kernel list , syzbot Date: Tue, 06 Apr 2021 16:16:29 +0300 In-Reply-To: References: <20210405195744.19386-1-paskripkin@gmail.com> Content-Type: text/plain; charset="UTF-8" User-Agent: Evolution 3.38.4 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Tue, 2021-04-06 at 08:21 -0400, Alexander Aring wrote: > Hi, > > On Mon, 5 Apr 2021 at 15:58, Pavel Skripkin > wrote: > > > > syzbot reported shift-out-of-bounds in nl802154_new_interface. > > The problem was in signed representation of enum nl802154_iftype > > > > enum nl802154_iftype { > >         /* for backwards compatibility TODO */ > >         NL802154_IFTYPE_UNSPEC = -1, > > ... > > > > Since, enum has negative value in it, objects of this type > > will be represented as signed integer. > > > >         type = nla_get_u32(info->attrs[NL802154_ATTR_IFTYPE]); > > > > u32 will be casted to signed, which can cause negative value type. > > > > Reported-by: syzbot+7bf7b22759195c9a21e9@syzkaller.appspotmail.com > > Signed-off-by: Pavel Skripkin > > Yes, this patch will fix the issue but we discussed that the problem > is deeper than such a fix. The real problem is that we are using a -1 > value which doesn't fit into the u32 netlink value and it gets > converted back and forward which we should avoid. > OK, thanks for feedback! > > - Alex With regards, Pavel Skripkin