From: Igor Pylypiv <ipylypiv@google.com>
Date: Tue, 30 Nov 2021 20:16:27 -0800
Subject: scsi: pm80xx: Do not call scsi_remove_host() in pm8001_alloc()
Git-commit: 653926205741add87a6cf452e21950eebc6ac10b
Patch-mainline: v5.16-rc5
References: git-fixes

Calling scsi_remove_host() before scsi_add_host() results in a crash:

 BUG: kernel NULL pointer dereference, address: 0000000000000108
 RIP: 0010:device_del+0x63/0x440
 Call Trace:
  device_unregister+0x17/0x60
  scsi_remove_host+0xee/0x2a0
  pm8001_pci_probe+0x6ef/0x1b90 [pm80xx]
  local_pci_probe+0x3f/0x90

We cannot call scsi_remove_host() in pm8001_alloc() because scsi_add_host()
has not been called yet at that point in time.

Function call tree:

  pm8001_pci_probe()
  |
  `- pm8001_pci_alloc()
  |  |
  |  `- pm8001_alloc()
  |     |
  |     `- scsi_remove_host()
  |
  `- scsi_add_host()

Link: https://lore.kernel.org/r/20211201041627.1592487-1-ipylypiv@google.com
Fixes: 05c6c029a44d ("scsi: pm80xx: Increase number of supported queues")
Reviewed-by: Vishakha Channapattan <vishakhavc@google.com>
Acked-by: Jack Wang <jinpu.wang@ionos.com>
Signed-off-by: Igor Pylypiv <ipylypiv@google.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Acked-by: Lee Duncan <lduncan@suse.com>
---
 drivers/scsi/pm8001/pm8001_init.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/drivers/scsi/pm8001/pm8001_init.c b/drivers/scsi/pm8001/pm8001_init.c
index bed8cc125544..fbfeb0b046dd 100644
--- a/drivers/scsi/pm8001/pm8001_init.c
+++ b/drivers/scsi/pm8001/pm8001_init.c
@@ -282,12 +282,12 @@ static int pm8001_alloc(struct pm8001_hba_info *pm8001_ha,
 	if (rc) {
 		pm8001_dbg(pm8001_ha, FAIL,
 			   "pm8001_setup_irq failed [ret: %d]\n", rc);
-		goto err_out_shost;
+		goto err_out;
 	}
 	/* Request Interrupt */
 	rc = pm8001_request_irq(pm8001_ha);
 	if (rc)
-		goto err_out_shost;
+		goto err_out;
 
 	count = pm8001_ha->max_q_num;
 	/* Queues are chosen based on the number of cores/msix availability */
@@ -423,8 +423,6 @@ static int pm8001_alloc(struct pm8001_hba_info *pm8001_ha,
 	pm8001_tag_init(pm8001_ha);
 	return 0;
 
-err_out_shost:
-	scsi_remove_host(pm8001_ha->shost);
 err_out_nodev:
 	for (i = 0; i < pm8001_ha->max_memcnt; i++) {
 		if (pm8001_ha->memoryMap.region[i].virt_ptr != NULL) {