Commit 724f6b43 authored by James Smart's avatar James Smart Committed by Martin K. Petersen
Browse files

scsi: lpfc: Fix use-after-free on unused nodes after port swap 

During target port swap, the swap logic ignores the DROPPED flag in the
nodes. As a node then moves into the UNUSED state, the reference count will
be dropped. If a node is later reused and moved out of the UNUSED state, an
access can result in a use-after-free assert.

Fix by having the port swap logic propagate the DROPPED flag when switching
nodes. This will avoid reference from being dropped.

Link: https://lore.kernel.org/r/20210412013127.2387-8-jsmart2021@gmail.com


Co-developed-by: default avatarJustin Tee <justin.tee@broadcom.com>
Signed-off-by: default avatarJustin Tee <justin.tee@broadcom.com>
Signed-off-by: default avatarJames Smart <jsmart2021@gmail.com>
Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
parent 304ee432

drivers/scsi/lpfc/lpfc_els.c

+18 −0
Original line number Diff line number Diff line
@@ -1691,6 +1691,15 @@ lpfc_plogi_confirm_nport(struct lpfc_hba *phba, uint32_t *prsp, 
	else

		new_ndlp->nlp_flag &= ~NLP_RPI_REGISTERED;



	/*

	 * Retain the DROPPED flag. This will take care of the init

	 * refcount when affecting the state change

	 */

	if (keep_new_nlp_flag & NLP_DROPPED)

		new_ndlp->nlp_flag |= NLP_DROPPED;

	else

		new_ndlp->nlp_flag &= ~NLP_DROPPED;



	ndlp->nlp_flag = keep_new_nlp_flag;



	/* if ndlp had NLP_UNREG_INP set, keep it */
@@ -1705,6 +1714,15 @@ lpfc_plogi_confirm_nport(struct lpfc_hba *phba, uint32_t *prsp, 
	else

		ndlp->nlp_flag &= ~NLP_RPI_REGISTERED;



	/*

	 * Retain the DROPPED flag. This will take care of the init

	 * refcount when affecting the state change

	 */

	if (keep_nlp_flag & NLP_DROPPED)

		ndlp->nlp_flag |= NLP_DROPPED;

	else

		ndlp->nlp_flag &= ~NLP_DROPPED;



	spin_unlock_irq(&new_ndlp->lock);

	spin_unlock_irq(&ndlp->lock);