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 62ABFC4321E for ; Wed, 30 Nov 2022 22:01:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229507AbiK3WBS (ORCPT ); Wed, 30 Nov 2022 17:01:18 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51308 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229483AbiK3WBR (ORCPT ); Wed, 30 Nov 2022 17:01:17 -0500 Received: from mail-ej1-x62a.google.com (mail-ej1-x62a.google.com [IPv6:2a00:1450:4864:20::62a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2C45F7E415; Wed, 30 Nov 2022 14:01:16 -0800 (PST) Received: by mail-ej1-x62a.google.com with SMTP id n20so44671542ejh.0; Wed, 30 Nov 2022 14:01:16 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=/XIHXbor+I8fmm71WeYjxkJYsXNm6XYVch/G1n4efNY=; b=HH3NlTjvoNOzY4km/62k+VS5yrNSlv1vda53o+xXrQiE11bpyynQH99WhlXY0TOW2d 59okSZB2FCLaVoNJ6ZuQ1xxVgGpf3tt8zSgb6K0+j+HXfVzN3G77P/Jh1R3FwKZ7EepO 2wX+RCaRObp2j6K0Lpwf2+Al7yXcOs5rKViIKU4KhDNc8zdytz33c2CFT0Z90kEoCY8u GNxuL+ftiUsRm9yOPRitRhi15WSA69k/An+RcVt6owdpzZA82lL/X+T0pqg1/MlAwKQ5 jU+mZf7VDM5BggThrz6egZgx140mEPzYS3IB29nNRofk0v4jM9KY79OGisZqIGpx5D1y 2xOg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=/XIHXbor+I8fmm71WeYjxkJYsXNm6XYVch/G1n4efNY=; b=fvC7vnO26odFgQtw7cYzm1jsP5/WmLZvwXakDp4TotcdLAjxy+x1ms1ChscOWcGIsY r71JlmXgFHtsY4AjeCBJmC+pIHixEnK7UDeqeDI5D/36wOYPkWkw6kBB7LRtL6EuTZqX i4pPbIwbKsZQJ/KFtdf4m8O04YUMoyPAJOTOx9v8p16ylweAfinxwAUDAuTuIVldL5iG Ieoxm9NaZjPD/02dMES5mbcZq7iTdFV+67zViBqyE0B4xV+VErlTmBCxA4JvmPkFFvzj 5Z8j45lYoUsp/zujzj6r52f81+9zbR+uoCTluOBdgaM14ucwpAovlt2ax5BKsMZ+Awed txfA== X-Gm-Message-State: ANoB5pnv7dQE4BhNd3cw+L1NcktT4GUaN/AThO0ZGDgKc10dXGsCS04M /kvrmkoGiwOZ+8EEUI9wo8g= X-Google-Smtp-Source: AA0mqf4y0DCvaVUbC1mhybCjAO03BlY2qqw3Y+DNQzkkkcYsf7OLMeNLSTAJ9eqOj/cPsc9fbE/HbA== X-Received: by 2002:a17:906:9618:b0:7ae:38a:fd with SMTP id s24-20020a170906961800b007ae038a00fdmr53995359ejx.501.1669845674597; Wed, 30 Nov 2022 14:01:14 -0800 (PST) Received: from skbuf ([188.26.184.222]) by smtp.gmail.com with ESMTPSA id ay17-20020a056402203100b00461e4498666sm1041466edb.11.2022.11.30.14.01.13 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 30 Nov 2022 14:01:14 -0800 (PST) Date: Thu, 1 Dec 2022 00:01:11 +0200 From: Vladimir Oltean To: Yuri Karpov Cc: Andrew Lunn , Florian Fainelli , "David S . Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, lvc-project@linuxtesting.org Subject: Re: [PATCH] net: dsa: fix NULL pointer dereference in seq_match() Message-ID: <20221130220111.zfrzckiyayaoka3z@skbuf> References: <20221130084431.3299054-1-YKarpov@ispras.ru> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20221130084431.3299054-1-YKarpov@ispras.ru> Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Wed, Nov 30, 2022 at 11:44:31AM +0300, Yuri Karpov wrote: > ptp_parse_header() result is not checked in seq_match() that can lead > to NULL pointer dereferense. > > Found by Linux Verification Center (linuxtesting.org) with SVACE. > > Fixes: c6fe0ad2c349 ("net: dsa: mv88e6xxx: add rx/tx timestamping support") > Signed-off-by: Yuri Karpov > --- > drivers/net/dsa/mv88e6xxx/hwtstamp.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/net/dsa/mv88e6xxx/hwtstamp.c b/drivers/net/dsa/mv88e6xxx/hwtstamp.c > index 331b4ca089ff..97f30795a2bb 100644 > --- a/drivers/net/dsa/mv88e6xxx/hwtstamp.c > +++ b/drivers/net/dsa/mv88e6xxx/hwtstamp.c > @@ -246,7 +246,7 @@ static int seq_match(struct sk_buff *skb, u16 ts_seqid) > > hdr = ptp_parse_header(skb, type); > > - return ts_seqid == ntohs(hdr->sequence_id); > + return hdr ? ts_seqid == ntohs(hdr->sequence_id) : 0; NACK. ptp_parse_header() will never return NULL when called from seq_match(). The skb comes from mv88e6xxx_get_rxts(), which takes it from ps->rx_queue. It was put there by mv88e6xxx_port_rxtstamp(), which prior to that, had a check for ptp_parse_header() returning NULL in mv88e6xxx_should_tstamp(). Please don't just blindly trust your tools. > } > > static void mv88e6xxx_get_rxts(struct mv88e6xxx_chip *chip, > -- > 2.34.1 >