drm/atomic: Only call atomic_destroy_state on a !NULL pointer

Browse source

The drm_atomic_commit structure is freed through the
drm_atomic_commit_put() function, that eventually calls
drm_atomic_commit_default_clear() by default when there's no active
users of that state.

It then iterates over all objects with a state, and will call the
atomic_destroy_state callback on the state pointer. The state pointer is
mostly used these days to point to which of the old or new state needs
to be freed, depending on whether the state was committed or not.

So it all makes sense.

However, with the hardware state readout support approaching, we might
have a state, with multiple objects in it, but no state to free because
we want them to persist. In such a case, the state pointer is going to
be NULL, and thus we'll end up with NULL pointer dereference.

Test if the state pointer is non-NULL before calling
atomic_destroy_state on it.

Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://lore.kernel.org/r/20260907-drm-state-readout-v5-8-5fa1ac7a5148@kernel.org
Signed-off-by: Maxime Ripard <mripard@kernel.org>

...

This commit is contained in:

Maxime Ripard 2026-09-07 15:23:44 +02:00

parent 4a7a146f1c

commit 5494df621f

No known key found for this signature in database

GPG key ID: 275FCE19A23DBE76

1 changed files with 15 additions and 8 deletions

Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL

Download patch file Download diff file Expand all files Collapse all files

23

drivers/gpu/drm/drm_atomic.c

View file