[PATCH 5.15.y] wifi: mac80211: check basic rates validity in sta_link_apply_parameters

["Hanne-Lotta Mäenpää" <hannelotta@gmail.com>]

From: Mikhail Lobanov <m.lobanov@rosa.ru>

[ Upstream commit 16ee3ea8faef8ff042acc15867a6c458c573de61 ]

When userspace sets supported rates for a new station via
NL80211_CMD_NEW_STATION, it might send a list that's empty
or contains only invalid values. Currently, we process these
values in sta_link_apply_parameters() without checking the result of
ieee80211_parse_bitrates(), which can lead to an empty rates bitmap.

A similar issue was addressed for NL80211_CMD_SET_BSS in commit
ce04abc3fcc6 ("wifi: mac80211: check basic rates validity").
This patch applies the same approach in sta_link_apply_parameters()
for NL80211_CMD_NEW_STATION, ensuring there is at least one valid
rate by inspecting the result of ieee80211_parse_bitrates().

Found by Linux Verification Center (linuxtesting.org) with Syzkaller.

Fixes: b95eb7f0eee4 ("wifi: cfg80211/mac80211: separate link params from station params")
Signed-off-by: Mikhail Lobanov <m.lobanov@rosa.ru>
Link: https://patch.msgid.link/20250317103139.17625-1-m.lobanov@rosa.ru
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
[ Summary of conflict resolutions:
  - Function ieee80211_parse_bitrates() takes channel width as its
    first parameter in mainline kernel version. In v5.15 the function
    takes the whole chandef struct as its first parameter.
  - The same function takes link station parameters as its last
    parameter, and in v5.15 they are in a struct called sta,
    instead of a struct called link_sta. ]
Signed-off-by: Hanne-Lotta Mäenpää <hannelotta@gmail.com>
---
 net/mac80211/cfg.c | 13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
index 2b77cb290788..706ff67f4254 100644
--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c
@@ -1658,12 +1658,13 @@ static int sta_apply_parameters(struct ieee80211_local *local,
 			return ret;
 	}
 
-	if (params->supported_rates && params->supported_rates_len) {
-		ieee80211_parse_bitrates(&sdata->vif.bss_conf.chandef,
-					 sband, params->supported_rates,
-					 params->supported_rates_len,
-					 &sta->sta.supp_rates[sband->band]);
-	}
+	if (params->supported_rates &&
+	    params->supported_rates_len &&
+	    !ieee80211_parse_bitrates(&sdata->vif.bss_conf.chandef,
+				      sband, params->supported_rates,
+				      params->supported_rates_len,
+				      &sta->sta.supp_rates[sband->band]))
+		return -EINVAL;
 
 	if (params->ht_capa)
 		ieee80211_ht_cap_ie_to_sta_ht_cap(sdata, sband,
-- 
2.50.0