From 8a4cd82d62b5ec7e5482333a72b58a4eea4979f0 Mon Sep 17 00:00:00 2001 From: Xiaoming Ni Date: Thu, 25 Mar 2021 11:51:11 +0800 Subject: [PATCH] nfc: fix refcount leak in llcp_sock_connect() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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)" Link: https://www.openwall.com/lists/oss-security/2020/11/01/1 Cc: #v3.6 Signed-off-by: Xiaoming Ni Signed-off-by: David S. Miller --- 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 68832ee4b9f8..9e2799ee1595 100644 --- a/net/nfc/llcp_sock.c +++ b/net/nfc/llcp_sock.c @@ -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);