From:   Jiasheng Jiang <jiasheng@iscas.ac.cn>
To:     johannes@sipsolutions.net, davem@davemloft.net, kuba@kernel.org
Cc:     linux-wireless@vger.kernel.org, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org, Jiasheng Jiang <jiasheng@iscas.ac.cn>
Subject: [PATCH v2] mac80211: mlme: check for null after calling kmemdup
Date:   Wed,  5 Jan 2022 09:33:08 +0800
Message-Id: <20220105013308.2011586-1-jiasheng@iscas.ac.cn>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

As the possible failure of the alloc, the ifmgd->assoc_req_ies might be
NULL pointer returned from kmemdup().
Therefore it might be better to free the skb and return in order to fail
the association, like ieee80211_assoc_success().

Fixes: 4d9ec73d2b78 ("cfg80211: Report Association Request frame IEs in association events")
Signed-off-by: Jiasheng Jiang <jiasheng@iscas.ac.cn>
---
v2: Change to fail the association if kmemdup returns NULL.
---
 net/mac80211/mlme.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index 9bed6464c5bd..b5dfdf953286 100644
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -1058,6 +1058,11 @@ static void ieee80211_send_assoc(struct ieee80211_sub_if_data *sdata)
 	pos = skb_tail_pointer(skb);
 	kfree(ifmgd->assoc_req_ies);
 	ifmgd->assoc_req_ies = kmemdup(ie_start, pos - ie_start, GFP_ATOMIC);
+	if (!ifmgd->assoc_req_ies) {
+		dev_kfree_skb(skb);
+		return;
+	}
+
 	ifmgd->assoc_req_ies_len = pos - ie_start;
 
 	drv_mgd_prepare_tx(local, sdata, 0);
-- 
2.25.1