From 00d025abdfdcc686052ed1d9c25f10ead680e620 Mon Sep 17 00:00:00 2001 From: Jiri Slaby Date: Wed, 13 May 2009 09:55:26 +0200 Subject: mac80211: pid, fix memory corruption commit a8659597bf744b0f8d2560e2a734b5c941569e0e upstream pid doesn't count with some band having more bitrates than the one associated the first time. Fix that by counting the maximal available bitrate count and allocate big enough space. Secondly, fix touching uninitialized memory which causes panics. Index sucked from this random memory points to the hell. The fix is to sort the rates on each band change. Also remove a comment which is wrong now. This version also contains half of mac80211: avoid NULL ptr deref when finding max_rates in PID and minstrel patch by John W. Linville, which is namely: - if (sband->n_bitrates > max_rates) + if (sband && sband->n_bitrates > max_rates) to fix oopses on one band devices. Signed-off-by: Jiri Slaby Cc: John W. Linville Signed-off-by: Greg Kroah-Hartman --- net/mac80211/rc80211_pid_algo.c | 71 ++++++++++++++++++++++------------------- 1 file changed, 39 insertions(+), 32 deletions(-) (limited to 'net') diff --git a/net/mac80211/rc80211_pid_algo.c b/net/mac80211/rc80211_pid_algo.c index a914ba73ccf..4077676bfa8 100644 --- a/net/mac80211/rc80211_pid_algo.c +++ b/net/mac80211/rc80211_pid_algo.c @@ -367,8 +367,40 @@ static void rate_control_pid_rate_init(void *priv, void *priv_sta, * Until that method is implemented, we will use the lowest supported * rate as a workaround. */ struct ieee80211_supported_band *sband; + struct rc_pid_info *pinfo = priv; + struct rc_pid_rateinfo *rinfo = pinfo->rinfo; + int i, j, tmp; + bool s; sband = local->hw.wiphy->bands[local->hw.conf.channel->band]; + + /* Sort the rates. This is optimized for the most common case (i.e. + * almost-sorted CCK+OFDM rates). Kind of bubble-sort with reversed + * mapping too. */ + for (i = 0; i < sband->n_bitrates; i++) { + rinfo[i].index = i; + rinfo[i].rev_index = i; + if (RC_PID_FAST_START) + rinfo[i].diff = 0; + else + rinfo[i].diff = i * pinfo->norm_offset; + } + for (i = 1; i < sband->n_bitrates; i++) { + s = 0; + for (j = 0; j < sband->n_bitrates - i; j++) + if (unlikely(sband->bitrates[rinfo[j].index].bitrate > + sband->bitrates[rinfo[j + 1].index].bitrate)) { + tmp = rinfo[j].index; + rinfo[j].index = rinfo[j + 1].index; + rinfo[j + 1].index = tmp; + rinfo[rinfo[j].index].rev_index = j; + rinfo[rinfo[j + 1].index].rev_index = j + 1; + s = 1; + } + if (!s) + break; + } + sta->txrate_idx = rate_lowest_index(local, sband, sta); sta->fail_avg = 0; } @@ -378,21 +410,23 @@ static void *rate_control_pid_alloc(struct ieee80211_local *local) struct rc_pid_info *pinfo; struct rc_pid_rateinfo *rinfo; struct ieee80211_supported_band *sband; - int i, j, tmp; - bool s; + int i, max_rates = 0; #ifdef CONFIG_MAC80211_DEBUGFS struct rc_pid_debugfs_entries *de; #endif - sband = local->hw.wiphy->bands[local->hw.conf.channel->band]; - pinfo = kmalloc(sizeof(*pinfo), GFP_ATOMIC); if (!pinfo) return NULL; + for (i = 0; i < IEEE80211_NUM_BANDS; i++) { + sband = local->hw.wiphy->bands[i]; + if (sband && sband->n_bitrates > max_rates) + max_rates = sband->n_bitrates; + } /* We can safely assume that sband won't change unless we get * reinitialized. */ - rinfo = kmalloc(sizeof(*rinfo) * sband->n_bitrates, GFP_ATOMIC); + rinfo = kmalloc(sizeof(*rinfo) * max_rates, GFP_ATOMIC); if (!rinfo) { kfree(pinfo); return NULL; @@ -410,33 +444,6 @@ static void *rate_control_pid_alloc(struct ieee80211_local *local) pinfo->rinfo = rinfo; pinfo->oldrate = 0; - /* Sort the rates. This is optimized for the most common case (i.e. - * almost-sorted CCK+OFDM rates). Kind of bubble-sort with reversed - * mapping too. */ - for (i = 0; i < sband->n_bitrates; i++) { - rinfo[i].index = i; - rinfo[i].rev_index = i; - if (RC_PID_FAST_START) - rinfo[i].diff = 0; - else - rinfo[i].diff = i * pinfo->norm_offset; - } - for (i = 1; i < sband->n_bitrates; i++) { - s = 0; - for (j = 0; j < sband->n_bitrates - i; j++) - if (unlikely(sband->bitrates[rinfo[j].index].bitrate > - sband->bitrates[rinfo[j + 1].index].bitrate)) { - tmp = rinfo[j].index; - rinfo[j].index = rinfo[j + 1].index; - rinfo[j + 1].index = tmp; - rinfo[rinfo[j].index].rev_index = j; - rinfo[rinfo[j + 1].index].rev_index = j + 1; - s = 1; - } - if (!s) - break; - } - #ifdef CONFIG_MAC80211_DEBUGFS de = &pinfo->dentries; de->dir = debugfs_create_dir("rc80211_pid", -- cgit v1.2.3-18-g5258