From: Xiaoming Ni <nixiaoming@huawei.com> commit 8a4cd82d62b5ec7e5482333a72b58a4eea4979f0 upstream. 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: c7aa12252f51 ("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> 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 be5abfcad7fd7..385937dbeb7c6 100644 --- a/net/nfc/llcp_sock.c +++ b/net/nfc/llcp_sock.c @@ -716,6 +716,7 @@ 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; } @@ -753,6 +754,7 @@ static int llcp_sock_connect(struct socket *sock, struct sockaddr *_addr, sock_unlink: nfc_llcp_put_ssap(local, llcp_sock->ssap); + nfc_llcp_local_put(llcp_sock->local); nfc_llcp_sock_unlink(&local->connecting_sockets, sk); -- 2.25.1