diff mbox series

[1/3] mt76 mt7915: take RCU read lock when calling ieee80211_bss_get_elem()

Message ID 510ef14986079c731ea2879b3095831b60e4f648.1626240767.git.ryder.lee@mediatek.com (mailing list archive)
State New, archived
Headers show
Series [1/3] mt76 mt7915: take RCU read lock when calling ieee80211_bss_get_elem() | expand

Commit Message

Ryder Lee July 14, 2021, 5:36 a.m. UTC
As ieee80211_bss_get_elem() derefences an RCU to return ssid_ie, both
the call to this function and any operation on this variable need
protection by the RCU read lock.

Signed-off-by: Ryder Lee <ryder.lee@mediatek.com>
---
 drivers/net/wireless/mediatek/mt76/mt7915/mcu.c | 3 +++
 1 file changed, 3 insertions(+)

Comments

Johannes Berg July 14, 2021, 7:31 a.m. UTC | #1
On Wed, 2021-07-14 at 13:36 +0800, Ryder Lee wrote:
> 
>  	if (!elem || elem->datalen < 10 ||
>  	    !(elem->data[10] &
>  	      WLAN_EXT_CAPA10_OBSS_NARROW_BW_RU_TOLERANCE_SUPPORT))
>  		data->tolerated = false;

Unrelated to this patch, but that looks like an off-by-one?

If datalen == 10, then you can only access data[0] through data[9], not
data[10]?

johannes
diff mbox series

Patch

diff --git a/drivers/net/wireless/mediatek/mt76/mt7915/mcu.c b/drivers/net/wireless/mediatek/mt76/mt7915/mcu.c
index 863aa18b3024..4d2e5b5e6389 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7915/mcu.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7915/mcu.c
@@ -923,12 +923,15 @@  static void mt7915_check_he_obss_narrow_bw_ru_iter(struct wiphy *wiphy,
 	struct mt7915_he_obss_narrow_bw_ru_data *data = _data;
 	const struct element *elem;
 
+	rcu_read_lock();
 	elem = ieee80211_bss_get_elem(bss, WLAN_EID_EXT_CAPABILITY);
 
 	if (!elem || elem->datalen < 10 ||
 	    !(elem->data[10] &
 	      WLAN_EXT_CAPA10_OBSS_NARROW_BW_RU_TOLERANCE_SUPPORT))
 		data->tolerated = false;
+
+	rcu_read_unlock();
 }
 
 static bool mt7915_check_he_obss_narrow_bw_ru(struct ieee80211_hw *hw,