[PATCH] libselinux: android: support exact match for a property key

[Jaekyun Seok via Selinux]

Performs exact match if a property key of property contexts ends with '$'
instead of prefix match.

This will enable to define an exact rule which can avoid unexpected
context assignment.

Signed-off-by: Jaekyun Seok <jaek...@google.com>
---
 libselinux/src/label_backends_android.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/libselinux/src/label_backends_android.c 
b/libselinux/src/label_backends_android.c
index cb8aae26..4611d396 100644
--- a/libselinux/src/label_backends_android.c
+++ b/libselinux/src/label_backends_android.c
@@ -258,8 +258,13 @@ static struct selabel_lookup_rec *property_lookup(struct 
selabel_handle *rec,
        }
 
        for (i = 0; i < data->nspec; i++) {
-               if (strncmp(spec_arr[i].property_key, key,
-                           strlen(spec_arr[i].property_key)) == 0) {
+               size_t property_key_len = strlen(spec_arr[i].property_key);
+               if (spec_arr[i].property_key[property_key_len - 1] == '$' &&
+                   strlen(key) == property_key_len - 1 &&
+                   strncmp(spec_arr[i].property_key, key, property_key_len - 
1) == 0) {
+                       break;
+               }
+               if (strncmp(spec_arr[i].property_key, key, property_key_len) == 
0) {
                        break;
                }
                if (strncmp(spec_arr[i].property_key, "*", 1) == 0)
-- 
2.15.0.rc0.271.g36b669edcc-goog