[PATCH 2/4] accel/rocket: Fix the panic in rocket_iommu_domain_put when the domain is NULL

[Chaoyi Chen <kernel@airkyi.com>]

From: Chaoyi Chen <chaoyi.chen@rock-chips.com>

In rocket_ioctl_submit_job(), since the domain is assigned last, an
error before that triggers rocket_job_put() -> rocket_job_cleanup()
-> rocket_iommu_domain_put() with the domain still NULL,
causing a panic in that function.

Therefore, the input parameters should be validated.

Fixes: 658ebeac3351 ("accel/rocket: Add IOCTL for BO creation")
Signed-off-by: Chaoyi Chen <chaoyi.chen@rock-chips.com>
---
 drivers/accel/rocket/rocket_drv.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/accel/rocket/rocket_drv.c b/drivers/accel/rocket/rocket_drv.c
index 8bbbce594883..77cd2ecce001 100644
--- a/drivers/accel/rocket/rocket_drv.c
+++ b/drivers/accel/rocket/rocket_drv.c
@@ -65,7 +65,8 @@ rocket_iommu_domain_get(struct rocket_file_priv *rocket_priv)
 void
 rocket_iommu_domain_put(struct rocket_iommu_domain *domain)
 {
-	kref_put(&domain->kref, rocket_iommu_domain_destroy);
+	if (domain)
+		kref_put(&domain->kref, rocket_iommu_domain_destroy);
 }
 
 static int
-- 
2.53.0