Re: [PATCH] scsi: lpfc: Fix lpfc_nodelist leak when processing unsolicited event

From: Daniel Wagner
Date: Mon May 25 2020 - 11:12:25 EST


On Mon, May 25, 2020 at 10:16:24PM +0800, Xiyu Yang wrote:
> In order to create or activate a new node, lpfc_els_unsol_buffer()
> invokes lpfc_nlp_init() or lpfc_enable_node() or lpfc_nlp_get(), all of
> them will return a reference of the specified lpfc_nodelist object to
> "ndlp" with increased refcnt.

lpfc_enable_node() is not changing the refcnt.

> When lpfc_els_unsol_buffer() returns, local variable "ndlp" becomes
> invalid, so the refcount should be decreased to keep refcount balanced.
> The reference counting issue happens in one exception handling path of
> lpfc_els_unsol_buffer(). When "ndlp" in DEV_LOSS, the function forgets
> to decrease the refcnt increased by lpfc_nlp_init() or
> lpfc_enable_node() or lpfc_nlp_get(), causing a refcnt leak.
> Fix this issue by calling lpfc_nlp_put() when "ndlp" in DEV_LOSS.

This sounds reasonable. At least the lpfc_nlp_init() and lpfc_nlp_get() case
needs this. And I suppose this is also ok for the lfpc_enable_node().

Reviewed-by: Daniel Wagner <dwagner@xxxxxxx>