This is a note to let you know that I've just added the patch titled nfc: fix refcount leak in llcp_sock_connect() to the 5.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: nfc-fix-refcount-leak-in-llcp_sock_connect.patch and it can be found in the queue-5.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 8a4cd82d62b5ec7e5482333a72b58a4eea4979f0 Mon Sep 17 00:00:00 2001 From: Xiaoming Ni <nixiaoming@xxxxxxxxxx> Date: Thu, 25 Mar 2021 11:51:11 +0800 Subject: nfc: fix refcount leak in llcp_sock_connect() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Xiaoming Ni <nixiaoming@xxxxxxxxxx> 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@xxxxxxxxxxx> Link: https://www.openwall.com/lists/oss-security/2020/11/01/1 Cc: <stable@xxxxxxxxxxxxxxx> #v3.6 Signed-off-by: Xiaoming Ni <nixiaoming@xxxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- net/nfc/llcp_sock.c | 2 ++ 1 file changed, 2 insertions(+) --- a/net/nfc/llcp_sock.c +++ b/net/nfc/llcp_sock.c @@ -704,6 +704,7 @@ static int llcp_sock_connect(struct sock 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); Patches currently in stable-queue which might be from nixiaoming@xxxxxxxxxx are queue-5.4/nfc-avoid-endless-loops-caused-by-repeated-llcp_sock_connect.patch queue-5.4/nfc-fix-memory-leak-in-llcp_sock_connect.patch queue-5.4/nfc-fix-refcount-leak-in-llcp_sock_bind.patch queue-5.4/nfc-fix-refcount-leak-in-llcp_sock_connect.patch