Messages in this thread Patch in this message | | | From | Xiyu Yang <> | Subject | [PATCH] net/tls: Fix sk_psock refcnt leak in bpf_exec_tx_verdict() | Date | Sat, 25 Apr 2020 20:54:37 +0800 |
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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> --- 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 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: -- 2.7.4
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