From: Luciano Coelho <luciano.coelho@nokia.com>
Date: Fri, 3 Jul 2009 05:25:08 +0000 (+0300)
Subject: mac80211: minstrel: avoid accessing negative indices in rix_to_ndx()
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=3938b45c1c75e53d45eb65ac253f12e86239c9ba;p=GitHub%2Fexynos8895%2Fandroid_kernel_samsung_universal8895.git

mac80211: minstrel: avoid accessing negative indices in rix_to_ndx()

If rix is not found in mi->r[], i will become -1 after the loop.  This value
is eventually used to access arrays, so we were accessing arrays with a
negative index, which is obviously not what we want to do.  This patch fixes
this potential problem.

Signed-off-by: Luciano Coelho <luciano.coelho@nokia.com>
Acked-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
---

diff --git a/net/mac80211/rc80211_minstrel.c b/net/mac80211/rc80211_minstrel.c
index b218b98fba7f..37771abd8f5a 100644
--- a/net/mac80211/rc80211_minstrel.c
+++ b/net/mac80211/rc80211_minstrel.c
@@ -66,7 +66,7 @@ rix_to_ndx(struct minstrel_sta_info *mi, int rix)
 	for (i = rix; i >= 0; i--)
 		if (mi->r[i].rix == rix)
 			break;
-	WARN_ON(mi->r[i].rix != rix);
+	WARN_ON(i < 0);
 	return i;
 }
 
@@ -181,6 +181,9 @@ minstrel_tx_status(void *priv, struct ieee80211_supported_band *sband,
 			break;
 
 		ndx = rix_to_ndx(mi, ar[i].idx);
+		if (ndx < 0)
+			continue;
+
 		mi->r[ndx].attempts += ar[i].count;
 
 		if ((i != IEEE80211_TX_MAX_RATES - 1) && (ar[i + 1].idx < 0))