Message ID | 1587819277-38974-1-git-send-email-xiyuyang19@fudan.edu.cn |
---|---|
State | Accepted |
Delegated to: | David Miller |
Headers | show |
Series | net/tls: Fix sk_psock refcnt leak in bpf_exec_tx_verdict() | expand |
From: Xiyu Yang <xiyuyang19@fudan.edu.cn> Date: Sat, 25 Apr 2020 20:54:37 +0800 > 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 <xiyuyang19@fudan.edu.cn> > Signed-off-by: Xin Tan <tanxin.ctf@gmail.com> Applied and queued up for -stable.
diff --git a/net/tls/tls_sw.c b/net/tls/tls_sw.c index 7d3bf86e6cbf..5fad144edaa3 100644 --- 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: