From 14e02ed3876f4ab0ed6d3f41972175f8b8df3d70 Mon Sep 17 00:00:00 2001 From: Thomas Zimmermann Date: Fri, 17 Oct 2025 11:13:36 +0200 Subject: [PATCH] drm/sysfb: Do not dereference NULL pointer in plane reset The plane state in __drm_gem_reset_shadow_plane() can be NULL. Do not deref that pointer, but forward NULL to the other plane-reset helpers. Clears plane->state to NULL. v2: - fix typo in commit description (Javier) Signed-off-by: Thomas Zimmermann Fixes: b71565022031 ("drm/gem: Export implementation of shadow-plane helpers") Reported-by: Dan Carpenter Closes: https://lore.kernel.org/dri-devel/aPIDAsHIUHp_qSW4@stanley.mountain/ Cc: Thomas Zimmermann Cc: Melissa Wen Cc: Maarten Lankhorst Cc: Maxime Ripard Cc: David Airlie Cc: Simona Vetter Cc: dri-devel@lists.freedesktop.org Cc: # v5.15+ Reviewed-by: Javier Martinez Canillas Link: https://patch.msgid.link/20251017091407.58488-1-tzimmermann@suse.de --- drivers/gpu/drm/drm_gem_atomic_helper.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/drm_gem_atomic_helper.c b/drivers/gpu/drm/drm_gem_atomic_helper.c index ebf305fb24f0..6fb55601252f 100644 --- a/drivers/gpu/drm/drm_gem_atomic_helper.c +++ b/drivers/gpu/drm/drm_gem_atomic_helper.c @@ -310,8 +310,12 @@ EXPORT_SYMBOL(drm_gem_destroy_shadow_plane_state); void __drm_gem_reset_shadow_plane(struct drm_plane *plane, struct drm_shadow_plane_state *shadow_plane_state) { - __drm_atomic_helper_plane_reset(plane, &shadow_plane_state->base); - drm_format_conv_state_init(&shadow_plane_state->fmtcnv_state); + if (shadow_plane_state) { + __drm_atomic_helper_plane_reset(plane, &shadow_plane_state->base); + drm_format_conv_state_init(&shadow_plane_state->fmtcnv_state); + } else { + __drm_atomic_helper_plane_reset(plane, NULL); + } } EXPORT_SYMBOL(__drm_gem_reset_shadow_plane); -- 2.47.3