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From:   Abinaya Kalaiselvan <akalaise@codeaurora.org>
To:     johannes@sipsolutions.net
Cc:     linux-wireless@vger.kernel.org,
        Abinaya Kalaiselvan <akalaise@codeaurora.org>
Subject: [PATCHv2] mac80211: fix NULL ptr dereference during mesh peer connection for non HE devices
Date:   Thu, 15 Apr 2021 16:17:05 +0530
Message-Id: <1618483625-31097-1-git-send-email-akalaise@codeaurora.org>
Precedence: bulk

"sband->iftype_data" is not assigned with any value for non HE supported
devices, which causes NULL pointer access during mesh peer connection
in those devices. Fix this by accessing the pointer after HE
capabilities condition check.

Fixes: 7f7aa94bcaf0 (mac80211: reduce peer HE MCS/NSS to own capabilities)
Signed-off-by: Abinaya Kalaiselvan <akalaise@codeaurora.org>
---
v2:
* ieee80211_sta_he_cap structure instance is initialized.

 net/mac80211/he.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/net/mac80211/he.c b/net/mac80211/he.c
index 0c0b970..96a47b0 100644
--- a/net/mac80211/he.c
+++ b/net/mac80211/he.c
@@ -111,7 +111,7 @@ ieee80211_he_cap_ie_to_sta_he_cap(struct ieee80211_sub_if_data *sdata,
 				  struct sta_info *sta)
 {
 	struct ieee80211_sta_he_cap *he_cap = &sta->sta.he_cap;
-	struct ieee80211_sta_he_cap own_he_cap = sband->iftype_data->he_cap;
+	struct ieee80211_sta_he_cap own_he_cap = {0};
 	struct ieee80211_he_cap_elem *he_cap_ie_elem = (void *)he_cap_ie;
 	u8 he_ppe_size;
 	u8 mcs_nss_size;
@@ -123,6 +123,8 @@ ieee80211_he_cap_ie_to_sta_he_cap(struct ieee80211_sub_if_data *sdata,
 	if (!he_cap_ie || !ieee80211_get_he_sta_cap(sband))
 		return;
 
+	 own_he_cap = sband->iftype_data->he_cap;
+
 	/* Make sure size is OK */
 	mcs_nss_size = ieee80211_he_mcs_nss_size(he_cap_ie_elem);
 	he_ppe_size =
-- 
2.7.4