On Mon, Oct 24, 2022 at 5:14 AM Thiébaud Weksteen <tweek@xxxxxxxxxx> wrote: > > selinux_check_access relies on string_to_security_class to resolve the > class index from its char* argument. There is no input validation done > on the string provided. It is possible to supply an argument containing > trailing backslashes (i.e., "sock_file//////") so that the paths built > in discover_class get truncated. The processing will then reference the > same permission file multiple time (e.g., perms/watch_reads will be > truncated to perms/watch). This will leak the memory allocated when > strdup'ing the permission name. The discover_class_cache will end up in > an invalid state (but not corrupted). > > Ensure that the class provided does not contain any path separator. > > Signed-off-by: Thiébaud Weksteen <tweek@xxxxxxxxxx> Acked-by: James Carter <jwcart2@xxxxxxxxx> > --- > libselinux/src/stringrep.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/libselinux/src/stringrep.c b/libselinux/src/stringrep.c > index 2fe69f43..592410e5 100644 > --- a/libselinux/src/stringrep.c > +++ b/libselinux/src/stringrep.c > @@ -63,6 +63,9 @@ static struct discover_class_node * discover_class(const char *s) > return NULL; > } > > + if (strchr(s, '/') != NULL) > + return NULL; > + > /* allocate a node */ > node = malloc(sizeof(struct discover_class_node)); > if (node == NULL) > -- > 2.38.0.135.g90850a2211-goog >
