From 83a09c10719661d8b51f1aa475ec52c13f3546d1 Mon Sep 17 00:00:00 2001
From: Xiaoming Ni <nixiaoming@huawei.com>
Date: Thu, 25 Mar 2021 11:51:12 +0800
Subject: [PATCH] nfc: fix memory leak in llcp_sock_connect()
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commit 7574fcdbdcb335763b6b322f6928dc0fd5730451 upstream.

In llcp_sock_connect(), use kmemdup to allocate memory for
 "llcp_sock->service_name". The memory is not released in the sock_unlink
label of the subsequent failure branch.
As a result, memory leakage occurs.

fix CVE-2020-25672

Fixes: d646960f7986 ("NFC: Initial LLCP support")
Reported-by: "kiyin(尹亮)" <kiyin@tencent.com>
Link: https://www.openwall.com/lists/oss-security/2020/11/01/1
Cc: <stable@vger.kernel.org> #v3.3
Signed-off-by: Xiaoming Ni <nixiaoming@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 net/nfc/llcp_sock.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/net/nfc/llcp_sock.c b/net/nfc/llcp_sock.c
index 724ba62e5fd2..a097de797ee7 100644
--- a/net/nfc/llcp_sock.c
+++ b/net/nfc/llcp_sock.c
@@ -757,6 +757,8 @@ sock_unlink:
 	nfc_llcp_local_put(llcp_sock->local);
 
 	nfc_llcp_sock_unlink(&local->connecting_sockets, sk);
+	kfree(llcp_sock->service_name);
+	llcp_sock->service_name = NULL;
 
 put_dev:
 	nfc_put_device(dev);
-- 
2.20.1