From: James Smart jsmart2021@gmail.com
[ Upstream commit 7740b615b6665e47f162e261d805f1bbbac15876 ]
The lpfc_sli4_nvmet_xri_aborted() routine takes out the abts_buf_list_lock and traverses the buffer contexts to match the xri. Upon match, it then takes the context lock before potentially removing the context from the associated buffer list. This violates the lock hierarchy used elsewhere in the driver of locking context, then the abts_buf_list_lock - thus a possible deadlock.
Resolve by: after matching, release the abts_buf_list_lock, then take the context lock, and if to be deleted from the list, retake the abts_buf_list_lock, maintaining lock hierarchy. This matches same list lock hierarchy as elsewhere in the driver
Link: https://lore.kernel.org/r/20210730163309.25809-1-jsmart2021@gmail.com Reported-by: Jia-Ju Bai baijiaju1990@gmail.com Signed-off-by: James Smart jsmart2021@gmail.com Signed-off-by: Martin K. Petersen martin.petersen@oracle.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/scsi/lpfc/lpfc_nvmet.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-)
diff --git a/drivers/scsi/lpfc/lpfc_nvmet.c b/drivers/scsi/lpfc/lpfc_nvmet.c index f2d9a3580887..6e3dd0b9bcfa 100644 --- a/drivers/scsi/lpfc/lpfc_nvmet.c +++ b/drivers/scsi/lpfc/lpfc_nvmet.c @@ -1797,19 +1797,22 @@ lpfc_sli4_nvmet_xri_aborted(struct lpfc_hba *phba, if (ctxp->ctxbuf->sglq->sli4_xritag != xri) continue;
- spin_lock(&ctxp->ctxlock); + spin_unlock_irqrestore(&phba->sli4_hba.abts_nvmet_buf_list_lock, + iflag); + + spin_lock_irqsave(&ctxp->ctxlock, iflag); /* Check if we already received a free context call * and we have completed processing an abort situation. */ if (ctxp->flag & LPFC_NVME_CTX_RLS && !(ctxp->flag & LPFC_NVME_ABORT_OP)) { + spin_lock(&phba->sli4_hba.abts_nvmet_buf_list_lock); list_del_init(&ctxp->list); + spin_unlock(&phba->sli4_hba.abts_nvmet_buf_list_lock); released = true; } ctxp->flag &= ~LPFC_NVME_XBUSY; - spin_unlock(&ctxp->ctxlock); - spin_unlock_irqrestore(&phba->sli4_hba.abts_nvmet_buf_list_lock, - iflag); + spin_unlock_irqrestore(&ctxp->ctxlock, iflag);
rrq_empty = list_empty(&phba->active_rrq_list); ndlp = lpfc_findnode_did(phba->pport, ctxp->sid);