From: Xiyu Yang xiyuyang19@fudan.edu.cn
[ 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 xiyuyang19@fudan.edu.cn Signed-off-by: Xin Tan tanxin.ctf@gmail.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/tls/tls_sw.c | 2 ++ 1 file changed, 2 insertions(+)
--- a/net/tls/tls_sw.c +++ b/net/tls/tls_sw.c @@ -800,6 +800,8 @@ static int bpf_exec_tx_verdict(struct sk *copied -= sk_msg_free(sk, msg); tls_free_open_rec(sk); } + if (psock) + sk_psock_put(sk, psock); return err; } more_data: