Claude review: drm/lease: cap object_count to avoid order > MAX_PAGE_ORDER warning

[Claude Code Review Bot <claude-review@example.com>]

Patch Review

**Correctness: Good.** The check is placed after `cl->object_count` is read into `object_count` (line 514) and before it's used for the `memdup_array_user` call (line 525) and passed to `fill_object_idr` → `kzalloc_objs` (line 389). The `goto out_lessor` target correctly drops the `drm_master` reference obtained at line 506. The fix prevents both the `kzalloc_objs` allocation (array of pointers, 8 bytes each on 64-bit → 4096 * 8 = 32KB, well within a single page order) and the `memdup_array_user` allocation (4096 * 4 = 16KB) from going overboard.

**Nit 1 — Format specifier mismatch:**

```c
drm_dbg_lease(dev, "object_count %zu exceeds max %u\n",
              object_count, DRM_MAX_LEASE_OBJECTS);
```

`object_count` is `size_t` so `%zu` is correct for it. `DRM_MAX_LEASE_OBJECTS` is `4096` which is an `int` constant, so `%u` works but `%d` would be more conventional for a plain integer literal. This is not a bug, just a minor style point — either is fine.

**Nit 2 — Limit derivation vs. hard-coded constant.** The value `4096` is chosen to sit below the `MAX_PAGE_ORDER` threshold. A more self-documenting approach would derive the limit from the actual allocation size, e.g.:

```c
#define DRM_MAX_LEASE_OBJECTS \
    ((PAGE_SIZE << MAX_PAGE_ORDER) / sizeof(struct drm_mode_object *))
```

That said, the hard-coded `4096` is generous enough for any realistic use (real leases have a handful of objects) and simple to understand. The comment explains the rationale. This is a matter of taste, not correctness.

**Nit 3 — `unlikely()` annotation.** The `unlikely()` on line 515 is fine and conventional for error-path guards on ioctl inputs, though opinions vary on whether the branch predictor needs the hint here. No issue.

**Nit 4 — Placement of the `#define`.** The `DRM_MAX_LEASE_OBJECTS` macro is placed between `fill_object_idr()` and `drm_mode_create_lease_ioctl()` in the middle of the file. Placing it near the top of the file with other constants or near the include block would be slightly more conventional, but this is minor.

**Overall:** The patch is correct, well-targeted, and addresses the reported syzbot issue cleanly. The commit message is clear and includes appropriate tags (Reported-by, Closes, Fixes, Signed-off-by). Good to merge with or without the nits addressed.

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