drm/i915/gvt: Avoid dereference a potential null pointer

Add sanity check for up_irq_info.

Signed-off-by: Xinyun Liu <xinyun.liu@intel.com>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>

diff --git a/drivers/gpu/drm/i915/gvt/interrupt.c b/drivers/gpu/drm/i915/gvt/interrupt.c
index 7a041b368f68861e552b590a88ca633416802cc3..1d79596da510e710d821386da8d8ca74cf7d1510 100644 (file)
--- a/drivers/gpu/drm/i915/gvt/interrupt.c
+++ b/drivers/gpu/drm/i915/gvt/interrupt.c
@@ -350,7 +350,8 @@ static void update_upstream_irq(struct intel_vgpu *vgpu,
                        clear_bits |= (1 << bit);
        }
 
-       WARN_ON(!up_irq_info);
+       if (WARN_ON(!up_irq_info))
+               return;
 
        if (up_irq_info->group == INTEL_GVT_IRQ_INFO_MASTER) {
                u32 isr = i915_mmio_reg_offset(up_irq_info->reg_base);