From e2d62a2bda963323038df0c80e96d95411e5bf71 Mon Sep 17 00:00:00 2001 From: Xiaoming Ni Date: Sun, 25 Apr 2021 15:31:52 +0800 Subject: [PATCH] nfc: fix refcount leak in llcp_sock_bind() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit stable inclusion from linux-4.19.187 commit adbb1d218c5f56dbae052765da83c0f57fce2a31 CVE: CVE-2020-25670 -------------------------------- commit c33b1cc62ac05c1dbb1cdafe2eb66da01c76ca8d upstream. nfc_llcp_local_get() is invoked in llcp_sock_bind(), 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-2020-25670 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 Signed-off-by: Greg Kroah-Hartman Signed-off-by: Yang Yingliang Reviewed-by: Xiu Jianfeng Reviewed-by: Yue Haibing Signed-off-by: Yang Yingliang --- 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 7d766350c08e..be5abfcad7fd 100644 --- a/net/nfc/llcp_sock.c +++ b/net/nfc/llcp_sock.c @@ -120,11 +120,13 @@ static int llcp_sock_bind(struct socket *sock, struct sockaddr *addr, int alen) llcp_sock->service_name_len, GFP_KERNEL); if (!llcp_sock->service_name) { + nfc_llcp_local_put(llcp_sock->local); ret = -ENOMEM; goto put_dev; } llcp_sock->ssap = nfc_llcp_get_sdp_ssap(local, llcp_sock); if (llcp_sock->ssap == LLCP_SAP_MAX) { + nfc_llcp_local_put(llcp_sock->local); kfree(llcp_sock->service_name); llcp_sock->service_name = NULL; ret = -EADDRINUSE; -- GitLab