fix segfault while dumping records

Signed-off-by: Felix Fietkau <nbd@openwrt.org>

diff --git a/cache.c b/cache.c
index dbd258d2f073a3e79802815b9b6e6969e767bf8e..927b9cf953875fd3344580dcc7b572b082480903 100644 (file)
--- a/cache.c
+++ b/cache.c
@@ -340,15 +340,12 @@ cache_answer(struct interface *iface, uint8_t *base, int blen, char *name, struc
 void
 cache_dump_records(struct blob_buf *buf, const char *name)
 {
-       struct cache_record *r, *q = avl_find_element(&records, name, r, avl);
+       struct cache_record *r, *last, *next;
        const char *txt;
        char buffer[INET6_ADDRSTRLEN];
 
-       if (!q)
-               return;
-
-       do {
-               r = q;
+       last = avl_last_element(&records, last, avl);
+       for (r = avl_find_element(&records, name, r, avl); r; r = next) {
                switch (r->type) {
                case TYPE_TXT:
                        if (r->txt && strlen(r->txt)) {
@@ -375,6 +372,12 @@ cache_dump_records(struct blob_buf *buf, const char *name)
                                blobmsg_add_string(buf, "ipv6", buffer);
                        break;
                }
-               q = avl_next_element(r, avl);
-       } while (q && !strcmp(r->record, q->record));
+
+               if (r == last)
+                       break;
+
+               next = avl_next_element(r, avl);
+               if (strcmp(r->record, next->record) != 0)
+                       break;
+       }
 }