[PATCH v2] media: iris: check decoder format allocations

[Ruoyu Wang <ruoyuw560@gmail.com>]

iris_vdec_inst_init() allocates source and destination v4l2_format
structures before initializing their fields. Allocation failures would
leave the function dereferencing NULL pointers during instance
initialization.

Allocate the formats into local variables and check each allocation before
assigning them to the instance. If the second allocation fails, free the
first allocation and return -ENOMEM. Store the pointers in the instance
only after both allocations have succeeded so the open path can unwind
cleanly.

Signed-off-by: Ruoyu Wang <ruoyuw560@gmail.com>
---
Changes in v2:
- Allocate the formats into local variables and assign them to the
  instance only after both allocations succeed, as requested in review.

 drivers/media/platform/qcom/iris/iris_vdec.c | 15 +++++++++++++--
 1 file changed, 13 insertions(+), 2 deletions(-)

diff --git a/drivers/media/platform/qcom/iris/iris_vdec.c b/drivers/media/platform/qcom/iris/iris_vdec.c
index 99d544e2af4f9..837f29f403bb7 100644
--- a/drivers/media/platform/qcom/iris/iris_vdec.c
+++ b/drivers/media/platform/qcom/iris/iris_vdec.c
@@ -19,10 +19,21 @@
 int iris_vdec_inst_init(struct iris_inst *inst)
 {
 	struct iris_core *core = inst->core;
+	struct v4l2_format *fmt_src, *fmt_dst;
 	struct v4l2_format *f;
 
-	inst->fmt_src = kzalloc_obj(*inst->fmt_src);
-	inst->fmt_dst = kzalloc_obj(*inst->fmt_dst);
+	fmt_src = kzalloc_obj(*fmt_src);
+	if (!fmt_src)
+		return -ENOMEM;
+
+	fmt_dst = kzalloc_obj(*fmt_dst);
+	if (!fmt_dst) {
+		kfree(fmt_src);
+		return -ENOMEM;
+	}
+
+	inst->fmt_src = fmt_src;
+	inst->fmt_dst = fmt_dst;
 
 	inst->fw_min_count = MIN_BUFFERS;
 
-- 
2.51.0