Return-path: Received: from mx2.redhat.com ([66.187.237.31]:42205 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754206AbZHLQRH (ORCPT ); Wed, 12 Aug 2009 12:17:07 -0400 Subject: Re: Libertas: Association request to the driver failed From: Dan Williams To: Jonathan Cameron Cc: Roel Kluin , Cyrill Gorcunov , Michael Buesch , libertas-dev@lists.infradead.org, linux-wireless@vger.kernel.org, linux-kernel@vger.kernel.org, "John W. Linville" , Daniel Mack In-Reply-To: <4A8281AD.1010807@cam.ac.uk> References: <20090807191156.GS19257@buzzloop.caiaq.de> <20090809102417.GH13639@buzzloop.caiaq.de> <4A7EAED8.9090900@gmail.com> <200908091310.56919.mb@bu3sch.de> <20090809191359.GG4805@lenovo> <4A7FF84C.7070708@gmail.com> <4A8281AD.1010807@cam.ac.uk> Content-Type: text/plain Date: Wed, 12 Aug 2009 11:16:43 -0500 Message-Id: <1250093803.31650.19.camel@localhost.localdomain> Mime-Version: 1.0 Sender: linux-wireless-owner@vger.kernel.org List-ID: On Wed, 2009-08-12 at 08:47 +0000, Jonathan Cameron wrote: > Hi All, > > After applying this patch I've been receiving 0x12 response from > an access point (association failed: not all rates supported) > to association requests. > > See below for queries on what is happening, > > Several arrays were read before checking whether the index was within > > bounds. ARRAY_SIZE() should be used to determine the size of arrays. > > > > rates->rates has an arraysize of 1, so calling get_common_rates() > > with a rates_size of MAX_RATES (14) was causing reads out of bounds. > > > > tmp_size can increment at most to MAX_RATES * ARRAY_SIZE(lbs_bg_rates), > > so that should be the number of elements of tmp[]. > > > > Signed-off-by: Roel Kluin > > --- > > > >> | Is it a good idea to use dynamic stack arrays in the kernel? > >> | What about kmalloc for dynamic allocations? > >> | > >> | -- > >> | Greetings, Michael. > >> > >> I saw one pattern in trace code (not sure if it's > >> still there) but personally don't like dynamic > >> stack arrays (though at moment the max value > >> being passed into routine is known maybe just > >> use MAX_RATES instead of (*rates_size)?). Hmm? > > > > Good point. > > > >> -- Cyrill > > > > Thanks, > > > > I think there was another problem in lbs_associate(), > > the memcpy already affected rates->rates. > > > > Also in get_common_rates() I think we can safely move the > > memset/memcpy, originally after label done, upwards. > > > > The patch below, if correct, is to be applied after the revert > > > > Roel > > > > diff --git a/drivers/net/wireless/libertas/assoc.c b/drivers/net/wireless/libertas/assoc.c > > index b9b3741..ba0164a 100644 > > --- a/drivers/net/wireless/libertas/assoc.c > > +++ b/drivers/net/wireless/libertas/assoc.c > > @@ -1,6 +1,7 @@ > > /* Copyright (C) 2006, Red Hat, Inc. */ > > > > #include > > +#include > > #include > > #include > > #include > > @@ -43,41 +44,41 @@ static int get_common_rates(struct lbs_private *priv, > > u16 *rates_size) > > { > > u8 *card_rates = lbs_bg_rates; > > - size_t num_card_rates = sizeof(lbs_bg_rates); > > - int ret = 0, i, j; > > - u8 tmp[30]; > > + int i, j; > > + u8 tmp[MAX_RATES * ARRAY_SIZE(lbs_bg_rates)]; > > size_t tmp_size = 0; > > > > /* For each rate in card_rates that exists in rate1, copy to tmp */ > > - for (i = 0; card_rates[i] && (i < num_card_rates); i++) { > > - for (j = 0; rates[j] && (j < *rates_size); j++) { > > + for (i = 0; i < ARRAY_SIZE(lbs_bg_rates) && card_rates[i]; i++) { > > + for (j = 0; j < *rates_size && rates[j]; j++) { > > if (rates[j] == card_rates[i]) > > tmp[tmp_size++] = card_rates[i]; > > } > > } > > > > lbs_deb_hex(LBS_DEB_JOIN, "AP rates ", rates, *rates_size); > > - lbs_deb_hex(LBS_DEB_JOIN, "card rates ", card_rates, num_card_rates); > > + lbs_deb_hex(LBS_DEB_JOIN, "card rates ", card_rates, > > + ARRAY_SIZE(lbs_bg_rates)); > > lbs_deb_hex(LBS_DEB_JOIN, "common rates", tmp, tmp_size); > > lbs_deb_join("TX data rate 0x%02x\n", priv->cur_rate); > > > > + memset(rates, 0, *rates_size); > > + *rates_size = min_t(u16, tmp_size, *rates_size); > > + memcpy(rates, tmp, *rates_size); > > + > > if (!priv->enablehwauto) { > > for (i = 0; i < tmp_size; i++) { > > if (tmp[i] == priv->cur_rate) > > - goto done; > > + break; > > + } > > + if (i == tmp_size) { > > + lbs_pr_alert("Previously set fixed data rate %#x isn't " > > + "compatible with the network.\n", > > + priv->cur_rate); > > + return -1; > > } > > - lbs_pr_alert("Previously set fixed data rate %#x isn't " > > - "compatible with the network.\n", priv->cur_rate); > > - ret = -1; > > - goto done; > > } > > - ret = 0; > > - > > -done: > > - memset(rates, 0, *rates_size); > > - *rates_size = min_t(int, tmp_size, *rates_size); > > - memcpy(rates, tmp, *rates_size); > > - return ret; > > + return 0; > > } > > > > > > @@ -321,8 +322,8 @@ static int lbs_associate(struct lbs_private *priv, > > > > rates = (struct mrvl_ie_rates_param_set *) pos; > > rates->header.type = cpu_to_le16(TLV_TYPE_RATES); > > - memcpy(&rates->rates, &bss->rates, MAX_RATES); > > - tmplen = MAX_RATES; > > + tmplen = min_t(u16, ARRAY_SIZE(rates->rates), MAX_RATES); > Isn't this always going to be 1? Switching back to original version > allows association to work for me. > > As is, it only allows one rate to be tested as ARRAY_SIZE(rates->rates) > is always 1 as it stands. No, it was basically supposed to be either the # of rates in rates, or MAX_RATES (or something like that). Basically, it should *never* be 1, it should be either the # of 802.11b rates (which is like 5) or the # of 802.11g rates (which is like 12 or 13 or something). But never 1. Dan > If this is the desired behaviour please explain why? > I'll admit I'm not really sure what should be happening, I've merely > been bisecting looking for what was causing a regression for me. > > > + memcpy(&rates->rates, &bss->rates, tmplen); > > if (get_common_rates(priv, rates->rates, &tmplen)) { > > ret = -1; > > goto done; > > @@ -598,7 +599,7 @@ static int lbs_adhoc_join(struct lbs_private *priv, > > > > /* Copy Data rates from the rates recorded in scan response */ > > memset(cmd.bss.rates, 0, sizeof(cmd.bss.rates)); > > - ratesize = min_t(u16, sizeof(cmd.bss.rates), MAX_RATES); > > + ratesize = min_t(u16, ARRAY_SIZE(cmd.bss.rates), MAX_RATES); > > memcpy(cmd.bss.rates, bss->rates, ratesize); > > if (get_common_rates(priv, cmd.bss.rates, &ratesize)) { > > lbs_deb_join("ADHOC_JOIN: get_common_rates returned error.\n"); > > > > _______________________________________________ > > libertas-dev mailing list > > libertas-dev@lists.infradead.org > > http://lists.infradead.org/mailman/listinfo/libertas-dev > > > > -- > To unsubscribe from this list: send the line "unsubscribe linux-wireless" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html