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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Justin Tee <justin.tee@broadcom.com>,
        James Smart <jsmart2021@gmail.com>,
        "Martin K. Petersen" <martin.petersen@oracle.com>
Subject: [PATCH 5.16 0866/1039] scsi: lpfc: Fix lpfc_force_rscn ndlp kref imbalance
Date:   Mon, 24 Jan 2022 19:44:15 +0100
Message-Id: <20220124184154.404731249@linuxfoundation.org>
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From: James Smart <jsmart2021@gmail.com>

commit 7576d48c64f36f6fea9df2882f710a474fa35f40 upstream.

Issuing lpfc_force_rscn twice results in an ndlp kref use-after-free call
trace.

A prior patch reworked the get/put handling by ensuring nlp_get was done
before WQE submission and a put was done in the completion path.
Unfortunately, the issue_els_rscn path had a piece of legacy code that did
a nlp_put, causing an imbalance on the ref counts.

Fixed by removing the unnecessary legacy code snippet.

Link: https://lore.kernel.org/r/20211204002644.116455-4-jsmart2021@gmail.com
Fixes: 4430f7fd09ec ("scsi: lpfc: Rework locations of ndlp reference taking")
Cc: <stable@vger.kernel.org> # v5.11+
Co-developed-by: Justin Tee <justin.tee@broadcom.com>
Signed-off-by: Justin Tee <justin.tee@broadcom.com>
Signed-off-by: James Smart <jsmart2021@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/scsi/lpfc/lpfc_els.c |    5 -----
 1 file changed, 5 deletions(-)

--- a/drivers/scsi/lpfc/lpfc_els.c
+++ b/drivers/scsi/lpfc/lpfc_els.c
@@ -3538,11 +3538,6 @@ lpfc_issue_els_rscn(struct lpfc_vport *v
 		return 1;
 	}
 
-	/* This will cause the callback-function lpfc_cmpl_els_cmd to
-	 * trigger the release of node.
-	 */
-	if (!(vport->fc_flag & FC_PT2PT))
-		lpfc_nlp_put(ndlp);
 	return 0;
 }