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

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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: 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>
This commit is contained in:
James Smart 2021-04-11 18:31:18 -07:00 committed by Martin K. Petersen
parent 304ee43238
commit 724f6b43a3
1 changed files with 18 additions and 0 deletions
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18
drivers/scsi/lpfc/lpfc_els.c
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@ -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);