Check relative path limits and binding failures without truncation

src/media_delivery/media_index.c

@@ -66,13 +66,15 @@ static int mi_location_valid(const char* location) {
 }
 
 int media_index_path(const char* base, const char* location, char path[MEDIA_PATH_MAX]) {
-    char clean[MEDIA_BASE_MAX];
+    char clean[MEDIA_BASE_MAX], full[MEDIA_PATH_MAX];
     if (!path) { DEBUG_ERROR(DEBUG_CATEGORY_MEDIA, "media_index path without output"); return -1; }
     if (mi_clean_path(base, clean, sizeof(clean)) || mi_location_valid(location)) return -1;
-    int size = snprintf(path, MEDIA_PATH_MAX, "%s%s%s", clean, clean[strlen(clean) - 1] == '/' ? "" : "/", location);
+    int size = !strcmp(clean, ".") ? snprintf(full, sizeof(full), "%s", location)
+        : snprintf(full, sizeof(full), "%s%s%s", clean, clean[strlen(clean) - 1] == '/' ? "" : "/", location);
     if (size >= MEDIA_PATH_MAX || size < 0) {
         DEBUG_ERROR(DEBUG_CATEGORY_MEDIA, "media_index joined path too long base=%s location=%s", clean, location); return -1;
     }
+    memcpy(path, full, (size_t)size + 1);
     return 0;
 }
 

tests/test_media_index_regressions.c

@@ -59,6 +59,9 @@ static void paths(void) {
     assert(media_index_path(root, "a//file", path) == -1 && media_index_path(root, "a/./file", path) == -1);
     assert(media_index_path(root, "C:/file", path) == -1 && media_index_path(root, "a\\file", path) == -1);
     memset(relative, 'a', sizeof(relative)); relative[sizeof(relative) - 1] = 0;
+    assert(!media_index_path(".", relative, path) && strlen(path) == MEDIA_PATH_MAX - 1);
+    assert(!media_index_location(path, ".", relative) && strlen(relative) == MEDIA_PATH_MAX - 1);
+    assert(!media_index_path(".", relative, relative) && strlen(relative) == MEDIA_PATH_MAX - 1);
     assert(media_index_path("/", relative, path) == -1);
     relative[sizeof(relative) - 2] = 0;
     assert(!media_index_path("/", relative, path) && strlen(path) == MEDIA_PATH_MAX - 1);
@@ -117,6 +120,12 @@ static void transactions(void) {
     assert(scalar(db, "SELECT count(*) FROM media_files WHERE node_sign!=zeroblob(64)") == 2);
     assert(media_index_register_downloaded(db, result.media_id, ids, result.content_hash, "conflict", "wrong", 1, 14, 7, 0, 0) == -1);
     assert(scalar(db, "SELECT count(*) FROM media_files WHERE chat_id='1'") == 2);
+    sql(db, "DELETE FROM media_files");
+    char long_path[MEDIA_PATH_MAX], relative[301]; memset(relative, 'x', sizeof(relative) - 1); relative[300] = 0;
+    assert(!media_index_path(root, relative, long_path));
+    int previous_limit = sqlite3_limit(db, SQLITE_LIMIT_LENGTH, 200);
+    assert(commit(db, "1", long_path) == -1 && !scalar(db, "SELECT count(*) FROM media_files"));
+    sqlite3_limit(db, SQLITE_LIMIT_LENGTH, previous_limit);
     result.num_blocks = INT_MAX;
     assert(commit(db, "1", path) == -1); result.num_blocks = 2;
     sqlite3_close(db);