Remove potential use after free (fctx) in rctx_resend.

diff --git a/lib/dns/resolver.c b/lib/dns/resolver.c
index 06787c0d64e394c4821c62245a1f402748f76f23..bb33c987b72755146d5304148adb61654568b989 100644 (file)
--- a/lib/dns/resolver.c
+++ b/lib/dns/resolver.c
@@ -9345,6 +9345,8 @@ rctx_resend(respctx_t *rctx, dns_adbaddrinfo_t *addrinfo) {
        isc_result_t result;
        fetchctx_t *fctx = rctx->fctx;
        bool bucket_empty;
+       dns_resolver_t *res = fctx->res;
+       unsigned int bucketnum;
 
        FCTXTRACE("resend");
        inc_stats(fctx->res, dns_resstatscounter_retry);
@@ -9354,12 +9356,13 @@ rctx_resend(respctx_t *rctx, dns_adbaddrinfo_t *addrinfo) {
                return;
        }
 
+       bucketnum = fctx->bucketnum;
        fctx_done(fctx, result, __LINE__);
-       LOCK(&fctx->res->buckets[fctx->bucketnum].lock);
+       LOCK(&res->buckets[bucketnum].lock);
        bucket_empty = fctx_decreference(fctx);
-       UNLOCK(&fctx->res->buckets[fctx->bucketnum].lock);
+       UNLOCK(&res->buckets[bucketnum].lock);
        if (bucket_empty) {
-               empty_bucket(fctx->res);
+               empty_bucket(res);
        }
 }