linux-kernel - [PATCH 3.13 113/162] mac80211: fix typo in starting baserate for rts_cts_rate

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <1415313426-9622-114-git-send-email-kamal@canonical.com>
Date:	Thu,  6 Nov 2014 14:36:17 -0800
From:	Kamal Mostafa <kamal@...onical.com>
To:	linux-kernel@...r.kernel.org, stable@...r.kernel.org,
	kernel-team@...ts.ubuntu.com
Cc:	Karl Beldan <karl.beldan@...ierawaves.com>,
	Johannes Berg <johannes.berg@...el.com>,
	Kamal Mostafa <kamal@...onical.com>
Subject: [PATCH 3.13 113/162] mac80211: fix typo in starting baserate for rts_cts_rate_idx

3.13.11.11 -stable review patch.  If anyone has any objections, please let me know.

------------------

From: Karl Beldan <karl.beldan@...ierawaves.com>

commit c7abf25af0f41be4b50d44c5b185d52eea360cb8 upstream.

It affects non-(V)HT rates and can lead to selecting an rts_cts rate
that is not a basic rate or way superior to the reference rate (ATM
rates[0] used for the 1st attempt of the protected frame data).

E.g, assuming drivers register growing (bitrate) sorted tables of
ieee80211_rate-s, having :
- rates[0].idx == d'2 and basic_rates == b'10100
will select rts_cts idx b'10011 & ~d'(BIT(2)-1), i.e. 1, likewise
- rates[0].idx == d'2 and basic_rates == b'10001
will select rts_cts idx b'10000
The first is not a basic rate and the second is > rates[0].

Also, wrt severity of the addressed misbehavior, ATM we only have one
rts_cts_rate_idx rather than one per rate table entry, so this idx might
still point to bitrates > rates[1..MAX_RATES].

Fixes: 5253ffb8c9e1 ("mac80211: always pick a basic rate to tx RTS/CTS for pre-HT rates")
Signed-off-by: Karl Beldan <karl.beldan@...ierawaves.com>
Signed-off-by: Johannes Berg <johannes.berg@...el.com>
Signed-off-by: Kamal Mostafa <kamal@...onical.com>
---
 net/mac80211/rate.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/mac80211/rate.c b/net/mac80211/rate.c
index 22b223f..74350c3 100644
--- a/net/mac80211/rate.c
+++ b/net/mac80211/rate.c
@@ -462,7 +462,7 @@ static void rate_fixup_ratelist(struct ieee80211_vif *vif,
 	 */
 	if (!(rates[0].flags & IEEE80211_TX_RC_MCS)) {
 		u32 basic_rates = vif->bss_conf.basic_rates;
-		s8 baserate = basic_rates ? ffs(basic_rates - 1) : 0;
+		s8 baserate = basic_rates ? ffs(basic_rates) - 1 : 0;
 
 		rate = &sband->bitrates[rates[0].idx];
 
-- 
1.9.1

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/