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From:   Dongliang Mu <dzm91@hust.edu.cn>
To:     Hans de Goede <hdegoede@redhat.com>,
        Mauro Carvalho Chehab <mchehab@kernel.org>,
        Sakari Ailus <sakari.ailus@linux.intel.com>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Dongliang Mu <dzm91@hust.edu.cn>,
        Andy Shevchenko <andy.shevchenko@gmail.com>
Cc:     linux-media@vger.kernel.org, linux-staging@lists.linux.dev,
        linux-kernel@vger.kernel.org
Subject: [PATCH] media: atomisp: move the sanity checks before variable dereferences
Date:   Mon, 29 May 2023 23:21:30 +0800
Message-Id: <20230529152136.11719-1-dzm91@hust.edu.cn>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

Smatch reports:

sh_css_load_firmware() warn: variable dereferenced before check 'fw_data'

The variable fw_data can be NULL in sh_css_load_firmware, resulting in
NULL pointer dereference.

Fix this by moving the sanity checks before variable dereferences.

Signed-off-by: Dongliang Mu <dzm91@hust.edu.cn>
---
 drivers/staging/media/atomisp/pci/sh_css_firmware.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/staging/media/atomisp/pci/sh_css_firmware.c b/drivers/staging/media/atomisp/pci/sh_css_firmware.c
index e7ef578db8ab..38b757c3df0a 100644
--- a/drivers/staging/media/atomisp/pci/sh_css_firmware.c
+++ b/drivers/staging/media/atomisp/pci/sh_css_firmware.c
@@ -229,6 +229,10 @@ sh_css_load_firmware(struct device *dev, const char *fw_data,
 	struct sh_css_fw_bi_file_h *file_header;
 	int ret;
 
+	/* some sanity checks */
+	if (!fw_data || fw_size < sizeof(struct sh_css_fw_bi_file_h))
+		return -EINVAL;
+
 	firmware_header = (struct firmware_header *)fw_data;
 	file_header = &firmware_header->file_header;
 	binaries = &firmware_header->binary_header;
@@ -243,10 +247,6 @@ sh_css_load_firmware(struct device *dev, const char *fw_data,
 		IA_CSS_LOG("successfully load firmware version %s", release_version);
 	}
 
-	/* some sanity checks */
-	if (!fw_data || fw_size < sizeof(struct sh_css_fw_bi_file_h))
-		return -EINVAL;
-
 	if (file_header->h_size != sizeof(struct sh_css_fw_bi_file_h))
 		return -EINVAL;
 
-- 
2.34.1