[PATCH AUTOSEL 4.4 11/68] mwifiex: fix potential NULL dereference and use after free
From: Sasha Levin <sashal@kernel.org>
Date: 2019-11-22 06:18:13
Also in:
linux-wireless, lkml, stable
Subsystem:
networking drivers (wireless), the rest · Maintainers:
Johannes Berg, Linus Torvalds
From: Pan Bian <redacted> [ Upstream commit 1dcd9429212b98bea87fc6ec92fb50bf5953eb47 ] There are two defects: (1) passing a NULL bss to mwifiex_save_hidden_ssid_channels will result in NULL dereference, (2) using bss after dropping the reference to it via cfg80211_put_bss. To fix them, the patch moves the buggy code to the branch that bss is not NULL and puts it before cfg80211_put_bss. Signed-off-by: Pan Bian <redacted> Signed-off-by: Kalle Valo <redacted> Signed-off-by: Sasha Levin <sashal@kernel.org> --- drivers/net/wireless/mwifiex/scan.c | 18 ++++++++++-------- 1 file changed, 10 insertions(+), 8 deletions(-)
diff --git a/drivers/net/wireless/mwifiex/scan.c b/drivers/net/wireless/mwifiex/scan.c
index b3fa3e4bed052..39b78dc1bd92b 100644
--- a/drivers/net/wireless/mwifiex/scan.c
+++ b/drivers/net/wireless/mwifiex/scan.c@@ -1873,15 +1873,17 @@ mwifiex_parse_single_response_buf(struct mwifiex_private *priv, u8 **bss_info, ETH_ALEN)) mwifiex_update_curr_bss_params(priv, bss); - cfg80211_put_bss(priv->wdev.wiphy, bss); - } - if ((chan->flags & IEEE80211_CHAN_RADAR) || - (chan->flags & IEEE80211_CHAN_NO_IR)) { - mwifiex_dbg(adapter, INFO, - "radar or passive channel %d\n", - channel); - mwifiex_save_hidden_ssid_channels(priv, bss); + if ((chan->flags & IEEE80211_CHAN_RADAR) || + (chan->flags & IEEE80211_CHAN_NO_IR)) { + mwifiex_dbg(adapter, INFO, + "radar or passive channel %d\n", + channel); + mwifiex_save_hidden_ssid_channels(priv, + bss); + } + + cfg80211_put_bss(priv->wdev.wiphy, bss); } } } else {
--
2.20.1