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 <xiyuyang19@fudan.edu.cn>
Signed-off-by: Xin Tan <tanxin.ctf@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Xiyu Yang 2020-04-25 20:54:37 +08:00 committed by David S. Miller
parent 6de556c310
commit 095f5614bf
1 changed files with 2 additions and 0 deletions

View File

@ -800,6 +800,8 @@ static int bpf_exec_tx_verdict(struct sk_msg *msg, struct sock *sk,
*copied -= sk_msg_free(sk, msg); *copied -= sk_msg_free(sk, msg);
tls_free_open_rec(sk); tls_free_open_rec(sk);
} }
if (psock)
sk_psock_put(sk, psock);
return err; return err;
} }
more_data: more_data: