[or-cvs] [tor/maint-0.2.1] Fix valgrind error when marking a descriptor as never-downloadable.

[Nick Mathewson]

Author: Nick Mathewson <nickm at torproject.org>
Date: Sun, 17 May 2009 02:01:09 -0400
Subject: Fix valgrind error when marking a descriptor as never-downloadable.
Commit: c0515b307c4c60d4a17158e47db1033540019b28

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.
---
 ChangeLog           |    2 ++
 src/or/routerlist.c |    7 ++++---
 2 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 05d5719..b84da4c 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 c6bfca4..de38e35 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);
       }
     }
-- 
1.5.6.5