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From:   Yuan Can <yuancan@huawei.com>
To:     <johannes@sipsolutions.net>, <davem@davemloft.net>,
        <yoshfuji@linux-ipv6.org>, <dsahern@kernel.org>,
        <edumazet@google.com>, <kuba@kernel.org>, <pabeni@redhat.com>,
        <linux-wireless@vger.kernel.org>, <netdev@vger.kernel.org>
CC:     <yuancan@huawei.com>
Subject: [PATCH 2/2] wifi: nl80211: Add checks for nla_nest_start() in nl80211_send_iface()
Date:   Sat, 26 Nov 2022 10:06:34 +0000
Message-ID: <20221126100634.106887-3-yuancan@huawei.com>
In-Reply-To: <20221126100634.106887-1-yuancan@huawei.com>
References: <20221126100634.106887-1-yuancan@huawei.com>
MIME-Version: 1.0
Content-Type: text/plain
Precedence: bulk

As the nla_nest_start() may fail with NULL returned, the return value needs
to be checked.

Fixes: ce08cd344a00 ("wifi: nl80211: expose link information for interfaces")
Signed-off-by: Yuan Can <yuancan@huawei.com>
---
 net/wireless/nl80211.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index 597c52236514..d2321c683398 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -3868,6 +3868,9 @@ static int nl80211_send_iface(struct sk_buff *msg, u32 portid, u32 seq, int flag
 			struct cfg80211_chan_def chandef = {};
 			int ret;
 
+			if (!link)
+				goto nla_put_failure;
+
 			if (nla_put_u8(msg, NL80211_ATTR_MLO_LINK_ID, link_id))
 				goto nla_put_failure;
 			if (nla_put(msg, NL80211_ATTR_MAC, ETH_ALEN,
-- 
2.17.1