[PATCH AUTOSEL 5.14 64/75] scsi: lpfc: Fix use-after-free in lpfc_unreg_rpi() routine

[Sasha Levin]

From: James Smart <jsmart2021@xxxxxxxxx>

[ Upstream commit 79b20beccea3a3938a8500acef4e6b9d7c66142f ]

An error is detected with the following report when unloading the driver:
  "KASAN: use-after-free in lpfc_unreg_rpi+0x1b1b"

The NLP_REG_LOGIN_SEND nlp_flag is set in lpfc_reg_fab_ctrl_node(), but the
flag is not cleared upon completion of the login.

This allows a second call to lpfc_unreg_rpi() to proceed with nlp_rpi set
to LPFC_RPI_ALLOW_ERROR.  This results in a use after free access when used
as an rpi_ids array index.

Fix by clearing the NLP_REG_LOGIN_SEND nlp_flag in
lpfc_mbx_cmpl_fc_reg_login().

Link: https://lore.kernel.org/r/20211020211417.88754-5-jsmart2021@xxxxxxxxx
Co-developed-by: Justin Tee <justin.tee@xxxxxxxxxxxx>
Signed-off-by: Justin Tee <justin.tee@xxxxxxxxxxxx>
Signed-off-by: James Smart <jsmart2021@xxxxxxxxx>
Signed-off-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/scsi/lpfc/lpfc_hbadisc.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/scsi/lpfc/lpfc_hbadisc.c b/drivers/scsi/lpfc/lpfc_hbadisc.c
index 7cc5920979f8a..6a7754105ce3a 100644
--- a/drivers/scsi/lpfc/lpfc_hbadisc.c
+++ b/drivers/scsi/lpfc/lpfc_hbadisc.c
@@ -4340,6 +4340,7 @@ lpfc_mbx_cmpl_fc_reg_login(struct lpfc_hba *phba, LPFC_MBOXQ_t *pmb)
 			 ndlp->nlp_state);
 
 	ndlp->nlp_flag |= NLP_RPI_REGISTERED;
+	ndlp->nlp_flag &= ~NLP_REG_LOGIN_SEND;
 	ndlp->nlp_type |= NLP_FABRIC;
 	lpfc_nlp_set_state(vport, ndlp, NLP_STE_UNMAPPED_NODE);
 
-- 
2.33.0