On Wed, 2024-07-10 at 18:54 -0400, Benjamin Marzinski wrote:
> On Tue, Jul 09, 2024 at 11:39:12PM +0200, Martin Wilck wrote:
> > Use sscanf to make the parsing of the UUID more robust.
> >
> > Signed-off-by: Martin Wilck <mwilck@xxxxxxxx>
> > ---
> > libmultipath/devmapper.c | 17 +++++++----------
> > 1 file changed, 7 insertions(+), 10 deletions(-)
> >
> > diff --git a/libmultipath/devmapper.c b/libmultipath/devmapper.c
> > index 56157af..d62a7dd 100644
> > --- a/libmultipath/devmapper.c
> > +++ b/libmultipath/devmapper.c
> > @@ -846,23 +846,20 @@ int dm_get_uuid(const char *name, char *uuid,
> > int uuid_len)
> >
> > static int is_mpath_part(const char *part_name, const char
> > *map_name)
> > {
> > - char *p;
> > - char part_uuid[DM_UUID_LEN], map_uuid[DM_UUID_LEN];
> > + char part_uuid[DM_UUID_LEN], map_uuid[DM_UUID_LEN], c;
> > + int np, nc;
> >
> > if (dm_get_dm_uuid(part_name, part_uuid) != DMP_OK)
> > return 0;
> >
> > + if (2 != sscanf(part_uuid, "part%d-%n" UUID_PREFIX "%c",
> > &np, &nc, &c)
>
> we should probably use "part%u-%n" so we can't match a "-" before the
> number.
That doesn't work, %u accepts negative numbers, too
(https://www.open-std.org/jtc1/sc22/wg14/www/docs/n1256.pdf)
That's why I use int and check whether the result is positive.
Martin
