[PATCH 5.15 103/171] scsi: pm80xx: Do not call scsi_remove_host() in pm8001_alloc()

Greg Kroah-Hartman
2021-12-13T10:03:49Z

From: Igor Pylypiv <ipylypiv@google.com>

commit 653926205741add87a6cf452e21950eebc6ac10b upstream.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/scsi/pm8001/pm8001_init.c | 6 ++----
1 file changed, 2 insertions(+), 4 deletions(-)

--- a/drivers/scsi/pm8001/pm8001_init.c
+++ b/drivers/scsi/pm8001/pm8001_init.c
@@ -281,12 +281,12 @@ static int pm8001_alloc(struct pm8001_hb
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 */
@@ -422,8 +422,6 @@ static int pm8001_alloc(struct pm8001_hb
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) {