Limit the maximum length of permission identifiers. Otherwise
formatting an access vector might fail in the common used helper
sepol_av_to_string().
The current longest permission within the Reference Policy is
x_application_data { paste_after_confirm } with a length of 19.
Reported-by: oss-fuzz (issue 64832)
Signed-off-by: Christian Göttsche <cgzones@xxxxxxxxxxxxxx>
---
The oss-fuzz issue got closed by the latest fuzzer updates (due to
unrelated changes that invalid the current reproducer), but the issue is
still valid.
---
libsepol/src/policydb_validate.c | 20 ++++++++++++++++++++
1 file changed, 20 insertions(+)
diff --git a/libsepol/src/policydb_validate.c b/libsepol/src/policydb_validate.c
index bd8e9f8f..72681120 100644
--- a/libsepol/src/policydb_validate.c
+++ b/libsepol/src/policydb_validate.c
@@ -366,12 +366,30 @@ bad:
return -1;
}
+static int validate_permission_wrapper(hashtab_key_t k, __attribute__((unused)) hashtab_datum_t d, void *args)
+{
+ sepol_handle_t *handle = args;
+ const char *name = k;
+ size_t len = strlen(name);
+
+ if (len == 0 || len >= 32)
+ goto bad;
+
+ return 0;
+
+bad:
+ ERR(handle, "Invalid permission");
+ return -1;
+}
+
static int validate_common_datum(sepol_handle_t *handle, const common_datum_t *common, validate_t flavors[])
{
if (validate_value(common->s.value, &flavors[SYM_COMMONS]))
goto bad;
if (common->permissions.table->nel == 0 || common->permissions.nprim > PERM_SYMTAB_SIZE)
goto bad;
+ if (hashtab_map(common->permissions.table, validate_permission_wrapper, handle))
+ goto bad;
return 0;
@@ -395,6 +413,8 @@ static int validate_class_datum(sepol_handle_t *handle, const class_datum_t *cla
goto bad;
if (class->permissions.nprim > PERM_SYMTAB_SIZE)
goto bad;
+ if (hashtab_map(class->permissions.table, validate_permission_wrapper, handle))
+ goto bad;
if (validate_constraint_nodes(handle, class->permissions.nprim, class->constraints, flavors))
goto bad;
if (validate_constraint_nodes(handle, 0, class->validatetrans, flavors))
--
2.43.0
