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: c7aa12252f ("NFC: Take a reference on the LLCP local pointer when creating a socket")
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> #v3.6
Signed-off-by: Xiaoming Ni <nixiaoming@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Xiaoming Ni 2021-03-25 11:51:11 +08:00 коммит произвёл David S. Miller
Родитель c33b1cc62a
Коммит 8a4cd82d62
1 изменённых файлов: 2 добавлений и 0 удалений

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@ -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 @@ sock_unlink:
sock_llcp_release:
nfc_llcp_put_ssap(local, llcp_sock->ssap);
nfc_llcp_local_put(llcp_sock->local);
put_dev:
nfc_put_device(dev);