On Mon, 2021-07-12 at 13:26 +0100, Salah Triki wrote:
> On Sat, Jul 10, 2021 at 10:04:48AM -0700, Joe Perches wrote:
> > On Sat, 2021-07-10 at 17:46 +0100, Salah Triki wrote:
> > > Replace sprintf() by scnprintf() in order to avoid buffer overflows.
> >
> > OK but also not strictly necessary. DAX_NAME_LEN is 30.
> >
> > Are you finding and changing these manually or with a script?
> >
> > > diff --git a/drivers/dax/bus.c b/drivers/dax/bus.c
> > []
> > > @@ -76,7 +76,7 @@ static ssize_t do_id_store(struct device_driver *drv,
> > > const char *buf,
> > > fields = sscanf(buf, "dax%d.%d", ®ion_id, &id);
> > > if (fields != 2)
> > > return -EINVAL;
> > > - sprintf(devname, "dax%d.%d", region_id, id);
> > > + scnprintf(devname, DAX_NAME_LEN, "dax%d.%d", region_id, id);
> > > if (!sysfs_streq(buf, devname))
> > > return -EINVAL;
> > >
> > >
> >
> >
>
> since region_id and id are unsigned long may be devname should be
> char[21].
I think you need to look at the code a bit more carefully.
unsigned int region_id, id;
Also the output is %d, so the maximum length of each output
int is 10 with a possible leading minus sign.
3 + 10 + 1 + 10 + 1. So 25 not 21 which is too small.
The %d uses could be changed to %u to make it 23.
But really it hardly matters as 30 is sufficent and the
function call depth here isn't particularly high.
> I'm finding and changing these manually.
coccinelle could help.
https://coccinelle.gitlabpages.inria.fr/website/
