From a41d985902c153c31c616fe183cf2ee331e95ecb Mon Sep 17 00:00:00 2001
From: Stanislav Lisovskiy <stanislav.lisovskiy@intel.com>
Date: Fri, 5 May 2023 11:22:12 +0300
Subject: [PATCH] drm/i915: Fix NULL ptr deref by checking new_crtc_state
Git-commit: a41d985902c153c31c616fe183cf2ee331e95ecb
Patch-mainline: v6.4-rc2
Alt-commit: 1d5b09f8daf859247a1ea65b0d732a24d88980d8
References: git-fixes
intel_atomic_get_new_crtc_state can return NULL, unless crtc state wasn't
obtained previously with intel_atomic_get_crtc_state, so we must check it
for NULLness here, just as in many other places, where we can't guarantee
that intel_atomic_get_crtc_state was called.
We are currently getting NULL ptr deref because of that, so this fix was
confirmed to help.
Fixes: 74a75dc90869 ("drm/i915/display: move plane prepare/cleanup to intel_atomic_plane.c")
Signed-off-by: Stanislav Lisovskiy <stanislav.lisovskiy@intel.com>
Reviewed-by: Andrzej Hajda <andrzej.hajda@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230505082212.27089-1-stanislav.lisovskiy@intel.com
(cherry picked from commit 1d5b09f8daf859247a1ea65b0d732a24d88980d8)
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Acked-by: Takashi Iwai <tiwai@suse.de>
---
drivers/gpu/drm/i915/display/intel_atomic_plane.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
--- a/drivers/gpu/drm/i915/display/intel_atomic_plane.c
+++ b/drivers/gpu/drm/i915/display/intel_atomic_plane.c
@@ -989,7 +989,7 @@ intel_prepare_plane_fb(struct drm_plane
int ret;
if (old_obj) {
- const struct intel_crtc_state *crtc_state =
+ const struct intel_crtc_state *new_crtc_state =
intel_atomic_get_new_crtc_state(state,
to_intel_crtc(old_plane_state->hw.crtc));
@@ -1004,7 +1004,7 @@ intel_prepare_plane_fb(struct drm_plane
* This should only fail upon a hung GPU, in which case we
* can safely continue.
*/
- if (intel_crtc_needs_modeset(crtc_state)) {
+ if (new_crtc_state && intel_crtc_needs_modeset(new_crtc_state)) {
ret = i915_sw_fence_await_reservation(&state->commit_ready,
old_obj->base.resv, NULL,
false, 0,