Patch "mac80211: handle lack of sband->bitrates in rates" has been added to the 5.8-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    mac80211: handle lack of sband->bitrates in rates

to the 5.8-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     mac80211-handle-lack-of-sband-bitrates-in-rates.patch
and it can be found in the queue-5.8 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit eea3fb4f8851b9831b5a8aa769a24be803c96620
Author: Thomas Pedersen <thomas@xxxxxxxxxxxx>
Date:   Mon Oct 5 09:45:21 2020 -0700

    mac80211: handle lack of sband->bitrates in rates
    
    [ Upstream commit 8b783d104e7f40684333d2ec155fac39219beb2f ]
    
    Even though a driver or mac80211 shouldn't produce a
    legacy bitrate if sband->bitrates doesn't exist, don't
    crash if that is the case either.
    
    This fixes a kernel panic if station dump is run before
    last_rate can be updated with a data frame when
    sband->bitrates is missing (eg. in S1G bands).
    
    Signed-off-by: Thomas Pedersen <thomas@xxxxxxxxxxxx>
    Link: https://lore.kernel.org/r/20201005164522.18069-1-thomas@xxxxxxxxxxxx
    Signed-off-by: Johannes Berg <johannes.berg@xxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
index 1079a07e43e49..d74cfec685477 100644
--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c
@@ -709,7 +709,8 @@ void sta_set_rate_info_tx(struct sta_info *sta,
 		u16 brate;
 
 		sband = ieee80211_get_sband(sta->sdata);
-		if (sband) {
+		WARN_ON_ONCE(sband && !sband->bitrates);
+		if (sband && sband->bitrates) {
 			brate = sband->bitrates[rate->idx].bitrate;
 			rinfo->legacy = DIV_ROUND_UP(brate, 1 << shift);
 		}
diff --git a/net/mac80211/sta_info.c b/net/mac80211/sta_info.c
index 05e966f1609e2..b93916c382cdb 100644
--- a/net/mac80211/sta_info.c
+++ b/net/mac80211/sta_info.c
@@ -2122,6 +2122,10 @@ static void sta_stats_decode_rate(struct ieee80211_local *local, u32 rate,
 		int rate_idx = STA_STATS_GET(LEGACY_IDX, rate);
 
 		sband = local->hw.wiphy->bands[band];
+
+		if (WARN_ON_ONCE(!sband->bitrates))
+			break;
+
 		brate = sband->bitrates[rate_idx].bitrate;
 		if (rinfo->bw == RATE_INFO_BW_5)
 			shift = 2;