scsi: smartpqi: Validate block layer host tag

Prevent OS crashes when a drive is hot removed during I/O stress test.

The I/O request pointer can be invalid if block layer provides incorrect
multi-queue host tag. This can lead to invalid I/O request pointer
dereference.

Reviewed-by: Scott Benesh <scott.benesh@microchip.com>
Reviewed-by: Scott Teel <scott.teel@microchip.com>
Reviewed-by: Mike McGowen <mike.mcgowen@microchip.com>
Reviewed-by: Kevin Barnett <kevin.barnett@microchip.com>
Signed-off-by: Murthy Bhat <Murthy.Bhat@microchip.com>
Signed-off-by: Don Brace <don.brace@microchip.com>
Link: https://lore.kernel.org/r/20230428153712.297638-7-don.brace@microchip.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

diff --git a/drivers/scsi/smartpqi/smartpqi_init.c b/drivers/scsi/smartpqi/smartpqi_init.c
index 7fe80be..f76b5a3 100644 (file)
--- a/drivers/scsi/smartpqi/smartpqi_init.c
+++ b/drivers/scsi/smartpqi/smartpqi_init.c
@@ -708,7 +708,8 @@ static inline struct pqi_io_request *pqi_alloc_io_request(struct pqi_ctrl_info *
                }
        }
 
-       pqi_reinit_io_request(io_request);
+       if (io_request)
+               pqi_reinit_io_request(io_request);
 
        return io_request;
 }