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@xxxxxxxxxxx>
>
> 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;
> >