On Sun, Sep 18, 2016 at 12:25:30PM +0800, Fam Zheng wrote: > sscanf is relatively loose (tolerate) on some invalid formats that we > should fail instead of generating a wrong uuid structure, like with > whitespaces and short strings. > > Add and use a helper function to first check the format. > > Signed-off-by: Fam Zheng <f...@redhat.com> > --- > util/uuid.c | 24 +++++++++++++++++++++++- > 1 file changed, 23 insertions(+), 1 deletion(-) > > diff --git a/util/uuid.c b/util/uuid.c > index 4701903..dd6b5fd 100644 > --- a/util/uuid.c > +++ b/util/uuid.c > @@ -61,12 +61,34 @@ char *qemu_uuid_unparse_strdup(const QemuUUID *uuid) > uu[13], uu[14], uu[15]); > } > > +static bool qemu_uuid_is_valid(const char *str) > +{ > + int i; > + > + for (i = 0; i < strlen(str); i++) { > + const char c = str[i]; > + if (i == 8 || i == 13 || i == 18 || i == 23) { > + if (str[i] != '-') { > + return false; > + } > + } else { > + if ((c >= '0' && c <= '9') || > + (c >= 'A' && c <= 'F') || > + (c >= 'a' && c <= 'f')) { > + continue; > + } > + return false; > + } > + } > + return i == 36; > +} > +
Doesn't verify variant / version, but it is a lot better than what was before. Reviewed-by: Jeff Cody <jc...@redhat.com> > int qemu_uuid_parse(const char *str, QemuUUID *uuid) > { > unsigned char *uu = &uuid->data[0]; > int ret; > > - if (strlen(str) != 36) { > + if (!qemu_uuid_is_valid(str)) { > return -1; > } > > -- > 2.7.4 > >