From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from wolverine01.qualcomm.com ([199.106.114.254]:26401 "EHLO wolverine01.qualcomm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750769Ab2DRGDl (ORCPT ); Wed, 18 Apr 2012 02:03:41 -0400 Message-ID: <4F8E592B.6010104@qca.qualcomm.com> (sfid-20120418_080344_510347_139DAAF5) Date: Wed, 18 Apr 2012 11:33:23 +0530 From: Bala Shanmugam MIME-Version: 1.0 To: Johannes Berg CC: , Subject: Re: [PATCH] cfg80211: Validate legacy rateset. References: <1334298173-4132-1-git-send-email-bkamatch@qca.qualcomm.com> (sfid-20120413_082304_815922_B50E6F19) <4F8C5776.6060209@sipsolutions.net> <4F8D24CC.5030205@qca.qualcomm.com> <4F8D7758.6040304@sipsolutions.net> In-Reply-To: <4F8D7758.6040304@sipsolutions.net> Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Sender: linux-wireless-owner@vger.kernel.org List-ID: On 04/17/2012 07:29 PM, Johannes Berg wrote: > On 4/17/2012 1:07 AM, Bala Shanmugam wrote: >> On 04/16/2012 11:01 PM, Johannes Berg wrote: >>> On 4/12/2012 11:22 PM, Bala Shanmugam wrote: >>>> Legacy rates are not validated while configuring >>>> tx rateset using iw. So below cmd is accepted by nl80211. >>>> sudo iw wlan2 set bitrates legacy-2.4 3 >>>> >>>> Validate legacy rates and return >>>> error while configuring improper rates. >>>> >>>> Signed-off-by: Bala Shanmugam >>>> --- >>>> net/wireless/nl80211.c | 2 ++ >>>> 1 files changed, 2 insertions(+), 0 deletions(-) >>>> >>>> diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c >>>> index e49da27..cc7bef7 100644 >>>> --- a/net/wireless/nl80211.c >>>> +++ b/net/wireless/nl80211.c >>>> @@ -5540,6 +5540,8 @@ static int nl80211_set_tx_bitrate_mask(struct >>>> sk_buff *skb, >>>> sband, >>>> nla_data(tb[NL80211_TXRATE_LEGACY]), >>>> nla_len(tb[NL80211_TXRATE_LEGACY])); >>>> + if (mask.control[band].legacy == 0) >>>> + return -EINVAL; >>> >>> I don't think this is right since it would also reject an >>> intentionally empty set. > >> This check comes into picture only when legacy rates are configured. >> For intentionally empty set "if (tb[NL80211_TXRATE_LEGACY])" condition >> will fail and control will not come here. I tested the same. >> With this patch >> "sudo iw wlan0 set bitrates mcs-5 6" executes without any error message. > > However, that means "don't change legacy settings", not "empty legacy > rateset". > > johannes Good catch. I didn't think of below configuration which is to specify empty legacy rateset for 2.4 band. sudo iw wlan0 set bitrates legacy-2.4 Correct me if I am wrong. Anyway we need to reject invalid legacy rates and below additional check will allow empty rateset and block invalid rates if (mask.control[band].legacy == 0 && nla_len(tb[NL80211_TXRATE_LEGACY])) return -EINVAL; Will send new patch. Regards, Bala.