[PATCH v4 4/6] drm/amdgpu/aca: Add missing NULL check for banks parameter in aca_banks_add_bank

[Sreeraj S Kurup <sreekuttan2156239@gmail.com>]

aca_banks_add_bank() verified that the 'bank' parameter was non-NULL,
but passed 'banks' directly into list_add_tail(&node->node, &banks->list)
and incremented 'banks->nr_banks' without validating whether 'banks' was
NULL.

Add a NULL check for 'banks' to prevent a kernel NULL pointer
dereference if an invalid pointer is passed by a caller.

Signed-off-by: Sreeraj S Kurup <sreekuttan2156239@gmail.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_aca.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_aca.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_aca.c
index c35f6be2ef77..dcddeb381628 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_aca.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_aca.c
@@ -49,7 +49,7 @@ static int aca_banks_add_bank(struct aca_banks *banks, struct aca_bank *bank)
 {
 	struct aca_bank_node *node;
 
-	if (!bank)
+	if (!banks || !bank)
 		return -EINVAL;
 
 	node = kvzalloc_obj(*node);
-- 
2.54.0