[PATCH 4.4 05/38] nfc: fix memory leak in llcp_sock_connect() - Greg Kroah-Hartman

From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: "Greg Kroah-Hartman" <gregkh@linuxfoundation.org>,
	stable@vger.kernel.org, "kiyin " <kiyin@tencent.com>,
	"Xiaoming Ni" <nixiaoming@huawei.com>,
	"David S. Miller" <davem@davemloft.net>
Subject: [PATCH 4.4 05/38] nfc: fix memory leak in llcp_sock_connect()
Date: Thu, 15 Apr 2021 16:46:59 +0200	[thread overview]
Message-ID: <20210415144413.529292544@linuxfoundation.org> (raw)
In-Reply-To: <20210415144413.352638802@linuxfoundation.org>

From: Xiaoming Ni <nixiaoming@huawei.com>

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(+)

--- a/net/nfc/llcp_sock.c
+++ b/net/nfc/llcp_sock.c
@@ -751,6 +751,8 @@ 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);


