2023-05-29 15:33:25

by Dongliang Mu

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

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 <[email protected]>
---
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

2023-05-29 16:02:34

by Hans de Goede

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

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 <[email protected]>

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;
>

2023-05-30 01:40:33

by Dongliang Mu

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

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 <[email protected]>
>
> 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;
>>