[tor-commits] [tor/maint-0.2.3] Fix a bug handling SENDME cells on nonexistent streams.

[arma at torproject.org]

commit 419f541aa737d3ab230ec2595d0614e2d94a5e44
Author: Nick Mathewson <nickm at torproject.org>
Date:   Fri Jul 6 07:29:54 2012 -0400

    Fix a bug handling SENDME cells on nonexistent streams.
    
    This could result in bizarre window values. Report and patch
    contributed pseudymously.  Fixes part of bug 6271. This bug was
    introduced before the first Tor release, in svn commit r152.
    
    (bug 6271, part a.)
---
 changes/bug6271 |    7 +++++++
 src/or/relay.c  |    7 ++++++-
 2 files changed, 13 insertions(+), 1 deletions(-)

diff --git a/changes/bug6271 b/changes/bug6271
new file mode 100644
index 0000000..06b129f
--- /dev/null
+++ b/changes/bug6271
@@ -0,0 +1,7 @@
+   o Major bugfixes
+
+     - Fix a bug handling SENDME cells on nonexistent streams that
+       could result in bizarre window values. Report and patch
+       contributed pseudymously.  Fixes part of bug 6271. This bug
+       was introduced before the first Tor release, in svn commit
+       r152.
diff --git a/src/or/relay.c b/src/or/relay.c
index b637fad..50c1455 100644
--- a/src/or/relay.c
+++ b/src/or/relay.c
@@ -1220,7 +1220,7 @@ connection_edge_process_relay_cell(cell_t *cell, circuit_t *circ,
                "'connected' received, no conn attached anymore. Ignoring.");
       return 0;
     case RELAY_COMMAND_SENDME:
-      if (!conn) {
+      if (!rh.stream_id) {
         if (layer_hint) {
           layer_hint->package_window += CIRCWINDOW_INCREMENT;
           log_debug(LD_APP,"circ-level sendme at origin, packagewindow %d.",
@@ -1235,6 +1235,11 @@ connection_edge_process_relay_cell(cell_t *cell, circuit_t *circ,
         }
         return 0;
       }
+      if (!conn) {
+        log_info(domain,"sendme cell dropped, unknown stream (streamid %d).",
+                 rh.stream_id);
+        return 0;
+      }
       conn->package_window += STREAMWINDOW_INCREMENT;
       log_debug(domain,"stream-level sendme, packagewindow now %d.",
                 conn->package_window);