drm/v3d: Reject invalid out_sync handles in submit ioctls

v3d_submit_process_post_deps() looks up the out_sync syncobj via
drm_syncobj_find(), and if userspace passes a non-zero handle that doesn't
refer to a valid syncobj, the lookup silently returns NULL and the
post-deps step skips publishing the submission's last fence to it. The
ioctl still returns success, leaving userspace to wait on a invalid
syncobj.

Instead of silently ignoring an invalid non-zero out_sync, move the syncobj
lookup to the submission and make it fail with -ENOENT up front, mirroring
the syncobj validation already done for in_sync. Now,
v3d_submit_process_post_deps() only does the fence replacement.

Note that the lookup is skipped when the multi-sync extension is in use,
since args->out_sync is unused in that case.

To keep cleanup symmetric on error paths, convert the function
v3d_put_multisync_post_deps() into a single function that releases the
references that were acquired but never published for both single-sync
and multi-sync.

Suggested-by: Tvrtko Ursulin <tvrtko.ursulin@igalia.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@igalia.com>
Link: https://patch.msgid.link/20260604-v3d-sched-misc-fixes-v4-11-c068f5bf5ccf@igalia.com
Signed-off-by: Maíra Canal <mcanal@igalia.com>

0 files changed, 0 insertions, 0 deletions