Re: [PATCH] net/tls: Fix sk_psock refcnt leak when in tls_data_ready()

From: David Miller
Date: Mon Apr 27 2020 - 14:23:14 EST


From: Xiyu Yang <xiyuyang19@xxxxxxxxxxxx>
Date: Sat, 25 Apr 2020 21:10:23 +0800

> tls_data_ready() invokes sk_psock_get(), which returns a reference of
> the specified sk_psock object to "psock" with increased refcnt.
>
> When tls_data_ready() 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
> tls_data_ready(). When "psock->ingress_msg" is empty 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 all paths when "psock" is
> not NULL.
>
> Signed-off-by: Xiyu Yang <xiyuyang19@xxxxxxxxxxxx>
> Signed-off-by: Xin Tan <tanxin.ctf@xxxxxxxxx>

Applied and queued up for -stable.