scsi: aic79xx: Fix NULL pointer dereference in device reset

Since commit c67e63800446 ("scsi: aic79xx: Do not reference SCSI command
when resetting device") the device reset SCB has no SCSI command, but
ahd_linux_dev_reset() still sets its residual, and ahd_abort_scbs(), which
completes it, sets its status. Seen on an AIC-7902 when a failing disk
triggered a device reset, which killed the SCSI error handler:

  BUG: kernel NULL pointer dereference, address: 0000009c
  EIP: ahd_linux_dev_reset.cold+0xee/0x26e

Add NULL command checks to the accessors in aic79xx_osm.h. Also skip
autosense for an SCB without a command and complete it with ahd_done()
right away: the REQUEST SENSE path can clear SCB_DEVICE_RESET, after which
ahd_done() would dereference the missing command.

Fixes: c67e63800446 ("scsi: aic79xx: Do not reference SCSI command when resetting device")
Cc: stable@vger.kernel.org
Reviewed-by: Hannes Reinecke <hare@kernel.org>
Signed-off-by: Andrew Luebke <andrew.luebke@gmail.com>
Assisted-by: LLM
Link: https://patch.msgid.link/20261026172032.749756-1-andrew.luebke@gmail.com
Signed-off-by: Martin K. Petersen (Oracle) <mkp@kernel.org>

0 files changed, 0 insertions, 0 deletions