[PATCH 2/4] nfc: fix refcount leak in llcp_sock_connect()
From: Xiaoming Ni <hidden>
Date: 2021-03-03 12:56:29
Also in:
lkml, stable
Subsystem:
networking [general], nfc subsystem, the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, David Heidelberg, Linus Torvalds
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)" <redacted>
Link: https://www.openwall.com/lists/oss-security/2020/11/01/1
Cc: <redacted> #v3.6
Signed-off-by: Xiaoming Ni <redacted>
---
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 @@ static int llcp_sock_connect(struct socket *sock, struct sockaddr *_addr, sock_llcp_release: nfc_llcp_put_ssap(local, llcp_sock->ssap); + nfc_llcp_local_put(llcp_sock->local); put_dev: nfc_put_device(dev);
--
2.27.0