[PATCH 6.1 0431/1146] wifi: rtl8xxxu: Fix use after rcu_read_unlock in rtl8xxxu_bss_info_changed

Greg Kroah-Hartman
2022-12-28T15:55:23Z

From: Bitterblue Smith <rtl8821cerfe2@gmail.com>

[ Upstream commit 7927afb5e27baac694f585b59c436ba323528dc2 ]

Commit a8b5aef2cca1 ("wifi: rtl8xxxu: gen2: Enable 40 MHz channel width")
introduced a line where the pointer returned by ieee80211_find_sta() is
used after rcu_read_unlock().

Move rcu_read_unlock() a bit lower to fix this.

Fixes: a8b5aef2cca1 ("wifi: rtl8xxxu: gen2: Enable 40 MHz channel width")
Signed-off-by: Bitterblue Smith <rtl8821cerfe2@gmail.com>
Reviewed-by: Ping-Ke Shih <pkshih@realtek.com>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://lore.kernel.org/r/3c82ad09-7593-3be1-1d2c-e58505fb43cb@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c b/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c
index 8d00ce805f1c..2d908296cf70 100644
--- a/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c
+++ b/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c
@@ -4654,7 +4654,6 @@ rtl8xxxu_bss_info_changed(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
if (sta->deflink.ht_cap.cap &
(IEEE80211_HT_CAP_SGI_40 | IEEE80211_HT_CAP_SGI_20))
sgi = 1;
- rcu_read_unlock();

highest_rate = fls(ramask) - 1;
if (highest_rate < DESC_RATE_MCS0) {
@@ -4679,6 +4678,7 @@ rtl8xxxu_bss_info_changed(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
else
rarpt->txrate.bw = RATE_INFO_BW_20;
}
+ rcu_read_unlock();
bit_rate = cfg80211_calculate_bitrate(&rarpt->txrate);
rarpt->bit_rate = bit_rate;
rarpt->desc_rate = highest_rate;
--
2.35.1