Return-path: Received: from ppsw-6.csi.cam.ac.uk ([131.111.8.136]:60198 "EHLO ppsw-6.csi.cam.ac.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751177AbZHLOrR (ORCPT ); Wed, 12 Aug 2009 10:47:17 -0400 Message-ID: <4A8281AD.1010807@cam.ac.uk> Date: Wed, 12 Aug 2009 08:47:41 +0000 From: Jonathan Cameron MIME-Version: 1.0 To: Roel Kluin CC: Cyrill Gorcunov , Michael Buesch , libertas-dev@lists.infradead.org, linux-wireless@vger.kernel.org, linux-kernel@vger.kernel.org, "John W. Linville" , Daniel Mack Subject: Re: Libertas: Association request to the driver failed 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> In-Reply-To: <4A7FF84C.7070708@gmail.com> Content-Type: text/plain; charset=us-ascii Sender: linux-wireless-owner@vger.kernel.org List-ID: 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. 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 >