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From:   Bragatheswaran Manickavel <bragathemanick0908@gmail.com>
To:     davem@davemloft.net, edumazet@google.com, kuba@kernel.org,
        pabeni@redhat.com
Cc:     Bragatheswaran Manickavel <bragathemanick0908@gmail.com>,
        dccp@vger.kernel.org, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org,
        syzbot+c71bc336c5061153b502@syzkaller.appspotmail.com
Subject: [PATCH net] dccp: check for ccid in ccid_hc_tx_send_packet
Date:   Sat, 28 Oct 2023 20:11:36 +0530
Message-Id: <20231028144136.3462-1-bragathemanick0908@gmail.com>
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ccid_hc_tx_send_packet might be called with a NULL ccid pointer
leading to a NULL pointer dereference

Below mentioned commit has similarly changes
commit 276bdb82dedb ("dccp: check ccid before dereferencing")

Reported-by: syzbot+c71bc336c5061153b502@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=c71bc336c5061153b502
Signed-off-by: Bragatheswaran Manickavel <bragathemanick0908@gmail.com>
---
 net/dccp/ccid.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/dccp/ccid.h b/net/dccp/ccid.h
index 105f3734dadb..1015dc2b9392 100644
--- a/net/dccp/ccid.h
+++ b/net/dccp/ccid.h
@@ -163,7 +163,7 @@ static inline int ccid_packet_dequeue_eval(const int return_code)
 static inline int ccid_hc_tx_send_packet(struct ccid *ccid, struct sock *sk,
 					 struct sk_buff *skb)
 {
-	if (ccid->ccid_ops->ccid_hc_tx_send_packet != NULL)
+	if (ccid != NULL && ccid->ccid_ops->ccid_hc_tx_send_packet != NULL)
 		return ccid->ccid_ops->ccid_hc_tx_send_packet(sk, skb);
 	return CCID_PACKET_SEND_AT_ONCE;
 }
-- 
2.34.1