drm/amdkfd: Validate CRIU-restored IDs before idr_alloc

The KFD CRIU restore flow restores previously saved object IDs from
userspace.

For event restore:

  kfd_criu_restore_event()
      -> create_signal_event() / create_other_event()
          -> allocate_event_notification_slot()
              -> idr_alloc(..., *restore_id, *restore_id + 1, ...)

For BO restore:

  criu_restore_memory_of_gpu()
      -> idr_alloc(..., bo_priv->idr_handle, ...)

In both cases, the restored ID comes from userspace-provided CRIU data.

idr_alloc() expects the ID range values to fit within signed int
limits. If a restored ID is larger than INT_MAX, it can trigger a WARN
in the IDR layer.

A kernel WARN is undesirable because it prints a warning trace and may
cause a panic or reboot on systems with panic_on_warn enabled.

Smatch reported these paths as allowing unchecked userspace values to
reach idr_alloc().

Add INT_MAX validation before using restored IDs in:

- kfd_criu_restore_event()
- criu_restore_memory_of_gpu()

If the restored ID is invalid, return -EINVAL.

This prevents invalid restore data from reaching the IDR layer and
avoids WARN-triggering paths, while keeping valid restore behavior
unchanged.

Fixes: 40e8a766a761 ("drm/amdkfd: CRIU checkpoint and restore events")
Reported-by: Dan Carpenter <error27@gmail.com>
Cc: Felix Kuehling <Felix.Kuehling@amd.com>
Cc: David Yat Sin <david.yatsin@amd.com>
Cc: Rajneesh Bhardwaj <rajneesh.bhardwaj@amd.com>
Signed-off-by: Srinivasan Shanmugam <srinivasan.shanmugam@amd.com>
Reviewed-by: David Yat Sin <david.yatsin@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

0 files changed, 0 insertions, 0 deletions