[PATCH v4 0/9] s390/vfio-ap: Fix bugs in vfio_ap device driver callback functions

[Anthony Krowiak <akrowiak@linux.ibm.com>]

During review of patches by the Sashiko AI, several pre-existing bugs were
discovered. This 9-patch series fixes those bugs.

Patch 2: Fix dereference matrix_mdev->kvm without checking for NULL
* Added block comment prior to traversing the matix_dev->mdev_list to 
  explain that it is safe to traverse the list because the 
  matrix_dev->guests_lock is taken in vfio_ap_on_cfg_changed() which is
  called prior to calling vfio_ap_mdev_cfg_remove to hopefully circumvent
  repeated LLM review comments that the list can change while traversing
  it.
* Added block comment prior to adding a matrix_mdev to the
  matrix_dev->mdev_list in vfio_ap_mdev_probe() to hopefully circumvent
  repeated LLM review comments that the list can change while traversing
  it.
  
Patch 3: Fix missing lock required to access list of ap_matrix_mdev objects
* Removed setting of matrix_mdev->req_trigger and 
  matrix_mdev->cfg_chg_trigger to NULL because matrix_mdev is kzalloc's and
  to avoid setting them to NULL after exposing the device to
  userspace via the prior call to vfio_register_emulated_iommu_dev(). 
  
Patch 6: Fix potential use of uninitialized apm_filtered bitmap
* Added block comment prior to zeroizing apm_filtered bitmap to explain why
  and hopefully prevent LLM review comments about it being uninitialized.

Patch 8: Fix NULL deref in status_show() during queue probe
* Added call to release_update_locks_for_mdev() prior to calling
  sysfs_remove_group() to fix an ABBA deadlock on the error path.


Anthony Krowiak (9):
  s390/vfio-ap: Fix stale do_remove flag across iterations in
    vfio_ap_mdev_cfg_remove
  s390/vfio-ap: Fix dereference matrix_mdev->kvm without checking for
    NULL
  s390/vfio-ap: Fix missing lock required to access list of
    ap_matrix_mdev objects
  s390/vfio-ap: Fix required lock not held during update of
    ap_matrix_mdev object
  s390/vfio-ap: Fix control domain removal in vfio_ap_mdev_cfg_remove
  s390/vfio-ap: fix potential use of uninitialized apm_filtered bitmap
  s390/vfio-ap: Fix hot-unplug skipped when last AP adapter or domain
    removed
  s390/vfio-ap: Fix NULL deref in status_show() during queue probe
  s390/vfio-ap: Fix memory leak when queue removed from host AP config

 drivers/s390/crypto/vfio_ap_ops.c | 145 ++++++++++++++++++++++--------
 1 file changed, 108 insertions(+), 37 deletions(-)

-- 
2.53.0