net/tls: Fix sk_psock refcnt leak in bpf_exec_tx_verdict()

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 <[email protected]> Signed-off-by: Xin Tan <[email protected]> Signed-off-by: David S. Miller <[email protected]>
Noltari · Apr 27, 2020 · 095f561 · 095f561
1 parent 6de556c
commit 095f561
Showing 1 changed file with 2 additions and 0 deletions.
diff --git a/net/tls/tls_sw.c b/net/tls/tls_sw.c
@@ -800,6 +800,8 @@ 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: