[PATCH] media: atomisp: move the sanity checks before variable dereferences

[PATCH] media: atomisp: move the sanity checks before variable dereferences

[Dongliang Mu]

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

Re: [PATCH] media: atomisp: move the sanity checks before variable dereferences

[Hans de Goede]

Hi,

On 5/29/23 17:21, Dongliang Mu wrote:
> 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>

Thank you for your patch, but the same patch has already been submitted
and merged into my media-atomisp branch about a week ago:

https://git.kernel.org/pub/scm/linux/kernel/git/hansg/linux.git/commit/?h=media-atomisp&id=c09907049eea9f12e959fb88c02a483a4c5eee89

> ---
>  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;
>  

Re: [PATCH] media: atomisp: move the sanity checks before variable dereferences

[Dongliang Mu]

On 5/29/23 23:46, Hans de Goede wrote:
> Hi,
> 
> On 5/29/23 17:21, Dongliang Mu wrote:
>> 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>
> 
> Thank you for your patch, but the same patch has already been submitted
> and merged into my media-atomisp branch about a week ago:
> 
> https://git.kernel.org/pub/scm/linux/kernel/git/hansg/linux.git/commit/?h=media-atomisp&id=c09907049eea9f12e959fb88c02a483a4c5eee89

I see. Thanks for your reply.

> 
>> ---
>>   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;
>>