Replace sprintf() by scnprintf() in order to avoid buffer overflows. Signed-off-by: Salah Triki <salah.triki@gmail.com> --- drivers/dax/bus.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/dax/bus.c b/drivers/dax/bus.c index 5aee26e1bbd6..bcae4be6ae76 100644 --- 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; -- 2.25.1
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; > >
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'm finding and changing these manually.
Thanx
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/
On Mon, Jul 12, 2021 at 09:14:53AM -0700, Joe Perches wrote:
> 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/
>
>
Thanx