[PATCH] scsi: csiostor: avoid null pointer dereference on card_fw allocation failure

[Colin King <colin.king@canonical.com>]

From: Colin Ian King <colin.king@canonical.com>

Currently if card_fw fails to be allocated then a null pointer
dereference occurs on card_fd when calling csio_hw_prep_fw. Fix this
by checking for a failed allocation and returning -ENOMEM.

Detected by CoverityScan, CID#1271213 ("Dereference null return value")

Signed-off-by: Colin Ian King <colin.king@canonical.com>
---
 drivers/scsi/csiostor/csio_hw.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/scsi/csiostor/csio_hw.c b/drivers/scsi/csiostor/csio_hw.c
index a10cf25ee7f9..aa637e9ea9ba 100644
--- a/drivers/scsi/csiostor/csio_hw.c
+++ b/drivers/scsi/csiostor/csio_hw.c
@@ -2275,8 +2275,8 @@ static int csio_hw_prep_fw(struct csio_hw *hw, struct fw_info *fw_info,
 }
 
 /*
- * Returns -EINVAL if attempts to flash the firmware failed
- * else returns 0,
+ * Returns -EINVAL if attempts to flash the firmware failed,
+ * -ENOMEM if allocation failed, else returns 0,
  * if flashing was not attempted because the card had the
  * latest firmware ECANCELED is returned
  */
@@ -2321,6 +2321,8 @@ csio_hw_flash_fw(struct csio_hw *hw, int *reset)
 	 * card
 	 */
 	card_fw = kmalloc(sizeof(*card_fw), GFP_KERNEL);
+	if (!card_fw)
+		return -ENOMEM;
 
 	/* upgrade FW logic */
 	ret = csio_hw_prep_fw(hw, fw_info, fw_data, fw_size, card_fw,
-- 
2.17.1