drm/v3d: bound CPU-job query writes to their destination BO

The V3D_SUBMIT_CPU CPU jobs take user-supplied offsets and indices and
consume them at exec time without checking that the accesses stay inside
their BO:

  - TIMESTAMP_QUERY and RESET_TIMESTAMP_QUERY write one u64 per query
    into bo[0] at a fully user-controlled per-query offset.
  - COPY_TIMESTAMP_QUERY copies one u64 per query into bo[0] at
    offset + i * stride, and reads each result from a user-controlled
    offset in the source bo[1].
  - COPY_PERFORMANCE_QUERY writes nperfmons * DRM_V3D_MAX_PERF_COUNTERS
    counter slots plus an availability slot into bo[0] at the same
    geometry.
  - INDIRECT_CSD reads three u32 work-group counts from bo[0] at a
    user-controlled offset, then writes each count back into the
    indirect BO at a user-controlled u32 index (wg_uniform_offsets[]).

A render-node user (DRM_RENDER_ALLOW, no master, no capability) can make
the handlers read or write past a BO's vmap mapping.

Validate the full access extent against the BO size once the BOs are
looked up, before the job is queued, rejecting out-of-range geometry
with -EINVAL. The copy extent offset + (count - 1) * stride + write_size
is computed in u64, mirroring the u8 * pointer arithmetic in the
executors: (count - 1) * stride is a u32 * u32 product that is exact in
u64, so one overflow check on the total guards the bound. The
performance slot count and the bare timestamp, copy-source and indirect
offsets are computed in u64 the same way, so a user value cannot wrap
the comparison.

Fixes: 18b8413b25b7 ("drm/v3d: Create a CPU job extension for a indirect CSD job")
Fixes: 9ba0ff3e083f ("drm/v3d: Create a CPU job extension for the timestamp query job")
Fixes: 34a101e64296 ("drm/v3d: Create a CPU job extension for the reset timestamp job")
Fixes: 6745f3e44a20 ("drm/v3d: Create a CPU job extension to copy timestamp query to a buffer")
Fixes: 209e8d2695ee ("drm/v3d: Create a CPU job extension for the copy performance query job")
Assisted-by: Claude:claude-opus-4-8
Signed-off-by: Michael Bommarito <michael.bommarito@gmail.com>
Reviewed-by: Maíra Canal <mcanal@igalia.com>
Signed-off-by: Maíra Canal <mcanal@igalia.com>
Link: https://patch.msgid.link/20260707221334.3854433-1-michael.bommarito@gmail.com

0 files changed, 0 insertions, 0 deletions