[PATCH] drm/nouveau: reorder nouveau_drm_device_fini

From: Mark Menzynski
Date: Wed May 04 2022 - 14:01:10 EST


Resources needed for output poll workers are destroyed in
nouveau_fbcon_fini() before output poll workers are cleared in
nouveau_display_fini(). This means there is a time between fbcon_fini
and display_fini, where if output poll happens, it crashes.

BUG: KASAN: use-after-free in
__drm_fb_helper_initial_config_and_unlock.cold+0x1f3/0x291
[drm_kms_helper]

Cc: Ben Skeggs <bskeggs@xxxxxxxxxx>
Cc: Karol Herbst <kherbst@xxxxxxxxxx>
Cc: Lyude Paul <lyude@xxxxxxxxxx>
Cc: David Airlie <airlied@xxxxxxxx>
Cc: Daniel Vetter <daniel@xxxxxxxx>
Cc: Sumit Semwal <sumit.semwal@xxxxxxxxxx>
Cc: "Christian König" <christian.koenig@xxxxxxx>
Cc: dri-devel@xxxxxxxxxxxxxxxxxxxxx
Cc: nouveau@xxxxxxxxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
Cc: linux-media@xxxxxxxxxxxxxxx
Cc: linaro-mm-sig@xxxxxxxxxxxxxxxx
Signed-off-by: Mark Menzynski <mmenzyns@xxxxxxxxxx>
---
drivers/gpu/drm/nouveau/nouveau_drm.c | 17 ++++++++---------
1 file changed, 8 insertions(+), 9 deletions(-)

diff --git a/drivers/gpu/drm/nouveau/nouveau_drm.c b/drivers/gpu/drm/nouveau/nouveau_drm.c
index 561309d447e0..773efdd20d2f 100644
--- a/drivers/gpu/drm/nouveau/nouveau_drm.c
+++ b/drivers/gpu/drm/nouveau/nouveau_drm.c
@@ -588,12 +588,6 @@ nouveau_drm_device_init(struct drm_device *dev)
if (ret)
goto fail_dispctor;

- if (dev->mode_config.num_crtc) {
- ret = nouveau_display_init(dev, false, false);
- if (ret)
- goto fail_dispinit;
- }
-
nouveau_debugfs_init(drm);
nouveau_hwmon_init(dev);
nouveau_svm_init(drm);
@@ -601,6 +595,12 @@ nouveau_drm_device_init(struct drm_device *dev)
nouveau_fbcon_init(dev);
nouveau_led_init(dev);

+ if (dev->mode_config.num_crtc) {
+ ret = nouveau_display_init(dev, false, false);
+ if (ret)
+ goto fail_dispinit;
+ }
+
if (nouveau_pmops_runtime()) {
pm_runtime_use_autosuspend(dev->dev);
pm_runtime_set_autosuspend_delay(dev->dev, 5000);
@@ -641,15 +641,14 @@ nouveau_drm_device_fini(struct drm_device *dev)
pm_runtime_forbid(dev->dev);
}

+ if (dev->mode_config.num_crtc)
+ nouveau_display_fini(dev, false, false);
nouveau_led_fini(dev);
nouveau_fbcon_fini(dev);
nouveau_dmem_fini(drm);
nouveau_svm_fini(drm);
nouveau_hwmon_fini(dev);
nouveau_debugfs_fini(drm);
-
- if (dev->mode_config.num_crtc)
- nouveau_display_fini(dev, false, false);
nouveau_display_destroy(dev);

nouveau_accel_fini(drm);
--
2.32.0