tdb: Make tdb_find circular-safe

Signed-off-by: Volker Lendecke <vl@samba.org>
Reviewed-by: Jeremy Allison <jra@samba.org>

diff --git a/lib/tdb/common/tdb.c b/lib/tdb/common/tdb.c
index 62df8eb1d320fefe5dd3ba97d05ed08dbb28c17f..c16e5779b874e7987250abf4a3c412e35cd83748 100644 (file)
--- a/lib/tdb/common/tdb.c
+++ b/lib/tdb/common/tdb.c
@@ -114,13 +114,18 @@ static tdb_off_t tdb_find(struct tdb_context *tdb, TDB_DATA key, uint32_t hash,
                        struct tdb_record *r)
 {
        tdb_off_t rec_ptr;
+       struct tdb_chainwalk_ctx chainwalk;
 
        /* read in the hash top */
        if (tdb_ofs_read(tdb, TDB_HASH_TOP(hash), &rec_ptr) == -1)
                return 0;
 
+       tdb_chainwalk_init(&chainwalk, rec_ptr);
+
        /* keep looking until we find the right record */
        while (rec_ptr) {
+               bool ok;
+
                if (tdb_rec_read(tdb, rec_ptr, r) == -1)
                        return 0;
 
@@ -131,13 +136,12 @@ static tdb_off_t tdb_find(struct tdb_context *tdb, TDB_DATA key, uint32_t hash,
                                      NULL) == 0) {
                        return rec_ptr;
                }
-               /* detect tight infinite loop */
-               if (rec_ptr == r->next) {
-                       tdb->ecode = TDB_ERR_CORRUPT;
-                       TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_find: loop detected.\n"));
+               rec_ptr = r->next;
+
+               ok = tdb_chainwalk_check(tdb, &chainwalk, rec_ptr);
+               if (!ok) {
                        return 0;
                }
-               rec_ptr = r->next;
        }
        tdb->ecode = TDB_ERR_NOEXIST;
        return 0;