Fix valgrind error when marking a descriptor as never-downloadable.

When we got a descriptor that we (as an authority) rejected as totally
bad, we were freeing it, then using the digest in its RAM to look up its
download status.  Caught by arma with valgrind.  Bugfix on 0.2.1.9-alpha.

2 files changed, 6 insertions, 3 deletions

diff --git a/ChangeLog b/ChangeLog
index 05d5719465..b84da4ceeb 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -21,6 +21,8 @@ Changes in version 0.2.1.15??? - ????-??-??
     - Stop using malloc_usable_size() to use more area than we had
       actually allocated: it was safe, but made valgrind really
       unhappy.  Bugfix on 0.2.0.x.
+    - Fix use of freed memory when deciding to mark a non-addable
+      descriptor as never-downloadable.  Bugfix on 0.2.1.9-alpha.
 
 
 Changes in version 0.2.1.14-rc - 2009-04-12
diff --git a/src/or/routerlist.c b/src/or/routerlist.c
index c6bfca4546..de38e354e0 100644
--- a/src/or/routerlist.c
+++ b/src/or/routerlist.c
@@ -3513,6 +3513,7 @@ router_load_routers_from_string(const char *s, const char *eos,
 
   SMARTLIST_FOREACH_BEGIN(routers, routerinfo_t *, ri) {
     was_router_added_t r;
+    char d[DIGEST_LEN];
     if (requested_fingerprints) {
       base16_encode(fp, sizeof(fp), descriptor_digests ?
                       ri->cache_info.signed_descriptor_digest :
@@ -3533,6 +3534,7 @@ router_load_routers_from_string(const char *s, const char *eos,
       }
     }
 
+    memcpy(d, ri->cache_info.signed_descriptor_digest, DIGEST_LEN);
     r = router_add_to_routerlist(ri, &msg, from_cache, !from_cache);
     if (WRA_WAS_ADDED(r)) {
       any_changed++;
@@ -3541,11 +3543,10 @@ router_load_routers_from_string(const char *s, const char *eos,
       smartlist_clear(changed);
     } else if (WRA_WAS_REJECTED(r)) {
       download_status_t *dl_status;
-      dl_status = router_get_dl_status_by_descriptor_digest(
-          ri->cache_info.signed_descriptor_digest);
+      dl_status = router_get_dl_status_by_descriptor_digest(d);
       if (dl_status) {
         log_info(LD_GENERAL, "Marking router %s as never downloadable",
-                 hex_str(ri->cache_info.signed_descriptor_digest, DIGEST_LEN));
+                 hex_str(d, DIGEST_LEN));
         download_status_mark_impossible(dl_status);
       }
     }