[PATCH 5.4 350/408] mac80211: handle lack of sband->bitrates in rates

Greg Kroah-Hartman
2020-10-27T14:46:12Z

From: Thomas Pedersen <thomas@adapt-ip.com>

[ 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@adapt-ip.com>
Link: https://lore.kernel.org/r/20201005164522.18069-1-thomas@adapt-ip.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/mac80211/cfg.c | 3 ++-
net/mac80211/sta_info.c | 4 ++++
2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
index a9dda5c228f60..fa293feef935d 100644
--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c
@@ -698,7 +698,8 @@ 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 f5d96107af6de..4f14d8a06915a 100644
--- a/net/mac80211/sta_info.c
+++ b/net/mac80211/sta_info.c
@@ -2083,6 +2083,10 @@ 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;
--
2.25.1