On Wed, Dec 1, 2021 at 5:16 AM Igor Pylypiv <ipylypiv@xxxxxxxxxx> wrote:
>
> 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() have not been called yet at that point of time.
>
> Function call tree:
>
> pm8001_pci_probe()
> |
> `- pm8001_pci_alloc()
> | |
> | `- pm8001_alloc()
> | |
> | `- scsi_remove_host()
> |
> `- scsi_add_host()
>
> Fixes: 05c6c029a44d ("scsi: pm80xx: Increase number of supported queues")
> Reviewed-by: Vishakha Channapattan <vishakhavc@xxxxxxxxxx>
> Signed-off-by: Igor Pylypiv <ipylypiv@xxxxxxxxxx>
Thanks!
Acked-by: Jack Wang <jinpu.wang@xxxxxxxxx>
> ---
> 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) {
> --
> 2.34.0.rc2.393.gf8c9666880-goog
>
