Check the result of kzalloc_obj() and return -ENOMEM
when the allocation fails instead of passing a NULL pointer
to the message initialization helpers, which would return -EINVAL.

Also separate kzalloc_obj() calls from variable declarations.

Signed-off-by: Triet Hoang <triet.hoang.dev@gmail.com>
---
Changes in v2:
- Clarify the commit message to describe the actual behavior change.
- Fix coding style regression
Changes in v3:
- Separate kzalloc_obj() calls from variable declarations.
---
 drivers/i2c/busses/i2c-cp2615.c | 21 ++++++++++++++++-----
 1 file changed, 16 insertions(+), 5 deletions(-)

diff --git a/drivers/i2c/busses/i2c-cp2615.c b/drivers/i2c/busses/i2c-cp2615.c
index 951de6249834..62192e919744 100644
--- a/drivers/i2c/busses/i2c-cp2615.c
+++ b/drivers/i2c/busses/i2c-cp2615.c
@@ -124,10 +124,15 @@ static int cp2615_check_status(enum cp2615_i2c_status status)
 static int
 cp2615_i2c_send(struct usb_interface *usbif, struct cp2615_i2c_transfer *i2c_w)
 {
-	struct cp2615_iop_msg *msg = kzalloc_obj(*msg);
 	struct usb_device *usbdev = interface_to_usbdev(usbif);
-	int res = cp2615_init_i2c_msg(msg, i2c_w);
+	struct cp2615_iop_msg *msg;
+	int res;
+
+	msg = kzalloc_obj(*msg);
+	if (!msg)
+		return -ENOMEM;
 
+	res = cp2615_init_i2c_msg(msg, i2c_w);
 	if (!res)
 		res = usb_bulk_msg(usbdev, usb_sndbulkpipe(usbdev, IOP_EP_OUT),
 				   msg, ntohs(msg->length), NULL, 0);
@@ -171,11 +176,16 @@ cp2615_i2c_recv(struct usb_interface *usbif, unsigned char tag, void *buf)
 /* Checks if the IOP is functional by querying the part's ID */
 static int cp2615_check_iop(struct usb_interface *usbif)
 {
-	struct cp2615_iop_msg *msg = kzalloc_obj(*msg);
-	struct cp2615_iop_accessory_info *info = (struct cp2615_iop_accessory_info *)&msg->data;
 	struct usb_device *usbdev = interface_to_usbdev(usbif);
-	int res = cp2615_init_iop_msg(msg, iop_GetAccessoryInfo, NULL, 0);
+	struct cp2615_iop_msg *msg;
+	struct cp2615_iop_accessory_info *info;
+	int res;
+
+	msg = kzalloc_obj(*msg);
+	if (!msg)
+		return -ENOMEM;
 
+	res = cp2615_init_iop_msg(msg, iop_GetAccessoryInfo, NULL, 0);
 	if (res)
 		goto out;
 
@@ -194,6 +204,7 @@ static int cp2615_check_iop(struct usb_interface *usbif)
 		goto out;
 	}
 
+	info = (struct cp2615_iop_accessory_info *)&msg->data;
 	switch (ntohs(info->part_id)) {
 	case PART_ID_A01:
 		dev_dbg(&usbif->dev, "Found A01 part. (WARNING: errata exists!)\n");
-- 
2.53.0

> Check the result of kzalloc_obj() and return -ENOMEM
> when the allocation fails instead of passing a NULL pointer
> to the message initialization helpers, which would return -EINVAL.
> 
> Also separate kzalloc_obj() calls from variable declarations.

* Can such a source code adjustment relieve further development concerns?
  https://cmu-sei.github.io/secure-coding-standards/sei-cert-c-coding-standard/rules/expressions-exp/exp34-c/

* How do you think about to add any tags (like “Fixes” and “Cc”) accordingly?
  https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/process/submitting-patches.rst?h=v7.3-rc1#n198
  https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/process/stable-kernel-rules.rst?h=v7.3-rc1#n3

* How do you think about to increase the application of scope-based resource management?


Regards,
Markus