Messages in this thread Patch in this message |  | | From | Thorsten Blum <> | | Subject | [PATCH] drm/vc4: fix NULL dereference in vc4_hvs_unbind | | Date | Sat, 2 May 2026 14:12:53 +0200 |
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With 'dtoverlay=vc4-kms-v3d,noaudio' and 'hdmi=off' on Raspberry Pi, unloading the vc4 module calls vc4_hvs_unbind() with dev_get_drvdata(master) returning NULL.
Return early when 'drm' is NULL before converting it to 'vc4' and before dereferencing 'vc4->hvs', preventing a kernel oops.
Fixes: c8b75bca92cb ("drm/vc4: Add KMS support for Raspberry Pi.") Cc: stable@vger.kernel.org Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev> --- drivers/gpu/drm/vc4/vc4_hvs.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/vc4/vc4_hvs.c b/drivers/gpu/drm/vc4/vc4_hvs.c index ee8d0738501b..9cb66f696fc7 100644 --- a/drivers/gpu/drm/vc4/vc4_hvs.c +++ b/drivers/gpu/drm/vc4/vc4_hvs.c @@ -1753,10 +1753,16 @@ static void vc4_hvs_unbind(struct device *dev, struct device *master, void *data) { struct drm_device *drm = dev_get_drvdata(master); - struct vc4_dev *vc4 = to_vc4_dev(drm); - struct vc4_hvs *hvs = vc4->hvs; + struct vc4_dev *vc4; + struct vc4_hvs *hvs; struct drm_mm_node *node, *next; + if (!drm) + return; + + vc4 = to_vc4_dev(drm); + hvs = vc4->hvs; + if (drm_mm_node_allocated(&vc4->hvs->mitchell_netravali_filter)) drm_mm_remove_node(&vc4->hvs->mitchell_netravali_filter);
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