From a15ccc88e516f4b56b7daa25a9ac1081dd148912 Mon Sep 17 00:00:00 2001 From: Xiyu Yang Date: Sat, 25 Apr 2020 20:54:37 +0800 Subject: [PATCH] net/tls: Fix sk_psock refcnt leak in bpf_exec_tx_verdict() [ Upstream commit 095f5614bfe16e5b3e191b34ea41b10d6fdd4ced ] bpf_exec_tx_verdict() invokes sk_psock_get(), which returns a reference of the specified sk_psock object to "psock" with increased refcnt. When bpf_exec_tx_verdict() returns, local variable "psock" becomes invalid, so the refcount should be decreased to keep refcount balanced. The reference counting issue happens in one exception handling path of bpf_exec_tx_verdict(). When "policy" equals to NULL but "psock" is not NULL, the function forgets to decrease the refcnt increased by sk_psock_get(), causing a refcnt leak. Fix this issue by calling sk_psock_put() on this error path before bpf_exec_tx_verdict() returns. Signed-off-by: Xiyu Yang Signed-off-by: Xin Tan Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/tls/tls_sw.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/net/tls/tls_sw.c b/net/tls/tls_sw.c index 41e9c2932b34..7e646b2f04af 100644 --- a/net/tls/tls_sw.c +++ b/net/tls/tls_sw.c @@ -797,6 +797,8 @@ static int bpf_exec_tx_verdict(struct sk_msg *msg, struct sock *sk, *copied -= sk_msg_free(sk, msg); tls_free_open_rec(sk); } + if (psock) + sk_psock_put(sk, psock); return err; } more_data: