Commit 8a4cd82d authored by Xiaoming Ni's avatar Xiaoming Ni Committed by David S. Miller
Browse files

nfc: fix refcount leak in llcp_sock_connect() 



nfc_llcp_local_get() is invoked in llcp_sock_connect(),
but nfc_llcp_local_put() is not invoked in subsequent failure branches.
As a result, refcount leakage occurs.
To fix it, add calling nfc_llcp_local_put().

fix CVE-2020-25671
Fixes: c7aa1225 ("NFC: Take a reference on the LLCP local pointer when creating a socket")
Reported-by: default avatar"kiyin(尹亮)" <kiyin@tencent.com>
Link: https://www.openwall.com/lists/oss-security/2020/11/01/1


Cc: <stable@vger.kernel.org> #v3.6
Signed-off-by: default avatarXiaoming Ni <nixiaoming@huawei.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent c33b1cc6

net/nfc/llcp_sock.c

+2 −0
Original line number Diff line number Diff line
@@ -704,6 +704,7 @@ static int llcp_sock_connect(struct socket *sock, struct sockaddr *_addr, 
	llcp_sock->local = nfc_llcp_local_get(local);

	llcp_sock->ssap = nfc_llcp_get_local_ssap(local);

	if (llcp_sock->ssap == LLCP_SAP_MAX) {

		nfc_llcp_local_put(llcp_sock->local);

		ret = -ENOMEM;

		goto put_dev;

	}
@@ -748,6 +749,7 @@ static int llcp_sock_connect(struct socket *sock, struct sockaddr *_addr, 


sock_llcp_release:

	nfc_llcp_put_ssap(local, llcp_sock->ssap);

	nfc_llcp_local_put(llcp_sock->local);



put_dev:

	nfc_put_device(dev);