6.6-stable review patch. If anyone has any objections, please let me know.
------------------
From: Aleksandr Mishin <amishin@xxxxxxxxxx>
[ Upstream commit 530f272053a5e72243a9cb07bb1296af6c346002 ]
In dpu_core_irq_callback_handler() callback function pointer is compared to NULL,
but then callback function is unconditionally called by this pointer.
Fix this bug by adding conditional return.
Found by Linux Verification Center (linuxtesting.org) with SVACE.
Fixes: c929ac60b3ed ("drm/msm/dpu: allow just single IRQ callback")
Signed-off-by: Aleksandr Mishin <amishin@xxxxxxxxxx>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>
Patchwork: https://patchwork.freedesktop.org/patch/588237/
Link: https://lore.kernel.org/r/20240408085523.12231-1-amishin@xxxxxxxxxx
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/gpu/drm/msm/disp/dpu1/dpu_hw_interrupts.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_interrupts.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_interrupts.c
index c413e9917d7eb..41f7c86bc2db9 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_interrupts.c
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_interrupts.c
@@ -221,9 +221,11 @@ static void dpu_core_irq_callback_handler(struct dpu_kms *dpu_kms, int irq_idx)
VERB("IRQ=[%d, %d]\n", DPU_IRQ_REG(irq_idx), DPU_IRQ_BIT(irq_idx));
- if (!irq_entry->cb)
+ if (!irq_entry->cb) {
DRM_ERROR("no registered cb, IRQ=[%d, %d]\n",
DPU_IRQ_REG(irq_idx), DPU_IRQ_BIT(irq_idx));
+ return;
+ }
atomic_inc(&irq_entry->count);
--
2.43.0
