From: Friedrich Vock friedrich.vock@gmx.de

The special case for VM passthrough doesn't check adev->nbio.funcs before dereferencing it. If GPUs that don't have an NBIO block are passed through, this leads to a NULL pointer dereference on startup.

Signed-off-by: Friedrich Vock friedrich.vock@gmx.de Fixes: 1bece222eabe ("drm/amdgpu: Clear doorbell interrupt status for Sienna Cichlid") Cc: Alex Deucher alexander.deucher@amd.com Cc: Christian König christian.koenig@amd.com Acked-by: Christian König christian.koenig@amd.com Signed-off-by: Alex Deucher alexander.deucher@amd.com Closes: https://gitlab.freedesktop.org/drm/amd/-/issues/3558 Cc: stable@vger.kernel.org # 5.15.x (cherry picked from commit 0cdb3f9740844b9d95ca413e3fcff11f81223ecf) --- drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c index 5f6c32ec674d..300d3b236bb3 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c @@ -5531,7 +5531,7 @@ int amdgpu_device_baco_exit(struct drm_device *dev) adev->nbio.funcs->enable_doorbell_interrupt) adev->nbio.funcs->enable_doorbell_interrupt(adev, true);

- if (amdgpu_passthrough(adev) && + if (amdgpu_passthrough(adev) && adev->nbio.funcs && adev->nbio.funcs->clear_doorbell_interrupt) adev->nbio.funcs->clear_doorbell_interrupt(adev);