[PATCH 0/3] s390/dasd: Fix BIODASDCHECKFMT issues and RCD retry handling

[Stefan Haberland <sth@linux.ibm.com>]

The BIODASDCHECKFMT ioctl gained several fixes as a result of issues
reported by Sashiko. Two patches address bugs introduced with the
original ioctl implementation: one prevents userspace from influencing
internal evaluation state through output-only fields, avoiding a kernel
heap information leak, and another fixes an error path that could crash
the kernel and leak request references.

The third patch fixes a longstanding z/VM-specific issue in RCD
processing. The Read Configuration Data request requires a special
buffer initialization before every start, but several restart paths
bypassed the existing reinitialization logic. As a result, successful
retries could return incomplete configuration data and lead to false
"Not all channel paths lead to the same device" reports for otherwise
identical minidisks.

Stefan Haberland (3):
  s390/dasd: Re-initialize RCD buffer with "V1.0" before every start
  s390/dasd: Fix wrong free and refcount leak in build_check_tcw error
    path
  s390/dasd: Don't trust userspace-supplied result field in format check

 drivers/s390/block/dasd.c       |  1 +
 drivers/s390/block/dasd_eckd.c  | 55 ++++++++++++---------------------
 drivers/s390/block/dasd_int.h   | 15 +++++++++
 drivers/s390/block/dasd_ioctl.c |  4 ++-
 4 files changed, 39 insertions(+), 36 deletions(-)

-- 
2.53.0