net/tls: Fix sk_psock refcnt leak when in tls_data_ready()

tls_data_ready() invokes sk_psock_get(), which returns a reference of
the specified sk_psock object to "psock" with increased refcnt.

When tls_data_ready() 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
tls_data_ready(). When "psock->ingress_msg" is empty 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 all paths when "psock" is
not NULL.

Signed-off-by: Xiyu Yang <xiyuyang19@fudan.edu.cn>
Signed-off-by: Xin Tan <tanxin.ctf@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/tls/tls_sw.c b/net/tls/tls_sw.c
index 704313dd082f389f319ab0192ffab411c86913b5..e23f94a5549b878ee3f9c75860425fbf3c632dbe 100644 (file)
--- a/net/tls/tls_sw.c
+++ b/net/tls/tls_sw.c
@@ -2083,8 +2083,9 @@ static void tls_data_ready(struct sock *sk)
        strp_data_ready(&ctx->strp);
 
        psock = sk_psock_get(sk);
-       if (psock && !list_empty(&psock->ingress_msg)) {
-               ctx->saved_data_ready(sk);
+       if (psock) {
+               if (!list_empty(&psock->ingress_msg))
+                       ctx->saved_data_ready(sk);
                sk_psock_put(sk, psock);
        }
 }