Re: [PATCH] staging: greybus: fix fw is NULL but dereferenced

Jian Dong
2021-03-25T11:05:28Z

On Thu, 25 Mar 2021 11:29:06 +0100
Greg KH <gregkh@linuxfoundation.org> wrote:

> On Thu, Mar 25, 2021 at 06:19:26PM +0800, Jian Dong wrote:
> > From: Jian Dong <dongjian@yulong.com>
> >
> > fixes coccicheck Error:
> >
> > drivers/staging/greybus/bootrom.c:301:41-45: ERROR:
> > fw is NULL but dereferenced.
> >
> > if procedure goto label directly, ret will be nefative, so the fw
> > is NULL and the if(condition) end with dereferenced fw. let's fix
> > it.
>
> Why is this all indented a space?
this maybe caused by my terminal, I will take notice next time.
>
> >
> > Signed-off-by: Jian Dong <dongjian@yulong.com>
> > ---
> > drivers/staging/greybus/bootrom.c | 8 ++++----
> > 1 file changed, 4 insertions(+), 4 deletions(-)
> >
> > diff --git a/drivers/staging/greybus/bootrom.c
> > b/drivers/staging/greybus/bootrom.c index a8efb86..0439efa 100644
> > --- a/drivers/staging/greybus/bootrom.c
> > +++ b/drivers/staging/greybus/bootrom.c
> > @@ -246,7 +246,7 @@ static int gb_bootrom_get_firmware(struct
> > gb_operation *op) struct gb_bootrom_get_firmware_response
> > *firmware_response; struct device *dev =
> > &op->connection->bundle->dev; unsigned int offset, size;
> > - enum next_request_type next_request;
> > + enum next_request_type next_request =
> > NEXT_REQ_GET_FIRMWARE; int ret = 0;
> >
> > /* Disable timeouts */
> > @@ -298,10 +298,10 @@ static int gb_bootrom_get_firmware(struct
> > gb_operation *op)
> > queue_work:
> > /* Refresh timeout */
> > - if (!ret && (offset + size == fw->size))
> > - next_request = NEXT_REQ_READY_TO_BOOT;
> > - else
> > + if (!!ret)
>
> That is hard to understand, please make this more obvious.
>
if (A && B) else (!A || !B)

So, when ret is NON-ZERO, set next_request as GET_FIRMWARE, else set
READ_TO_BOOT. but if second express is flase, next_request still
need be set as GET_FIRMWARE, So, I initialze it as GET_FIRMWARE.

this is will keep consistent with the origin conditional express:
both ret is ZERO and second express TRUE, then set as READ_TO_BOOT,
else set as GET_FIRMWARE.

> thanks,
>
> greg k-h