[tor-commits] [tor/maint-0.4.2] hs-v3: Remove BUG() that can occur normally

[nickm at torproject.org]

commit 88489cd29006f093e1a5572711b26ee1b057e359
Author: David Goulet <dgoulet at torproject.org>
Date:   Tue Feb 4 10:13:10 2020 -0500

    hs-v3: Remove BUG() that can occur normally
    
    Fixes #28992
    
    Signed-off-by: David Goulet <dgoulet at torproject.org>
---
 changes/ticket28992        |  3 +++
 src/feature/hs/hs_client.c | 11 ++++++++---
 2 files changed, 11 insertions(+), 3 deletions(-)

diff --git a/changes/ticket28992 b/changes/ticket28992
new file mode 100644
index 000000000..3e45d73e4
--- /dev/null
+++ b/changes/ticket28992
@@ -0,0 +1,3 @@
+  o Minor bugfixes (onion service v3, client):
+    - Remove a BUG() that is causing a stacktrace for a situation that very
+      rarely happens but still can. Fixes bug 28992; bugfix on 0.3.2.1-alpha.
diff --git a/src/feature/hs/hs_client.c b/src/feature/hs/hs_client.c
index fd2d26645..b045e1899 100644
--- a/src/feature/hs/hs_client.c
+++ b/src/feature/hs/hs_client.c
@@ -596,9 +596,14 @@ send_introduce1(origin_circuit_t *intro_circ,
   /* We need to find which intro point in the descriptor we are connected to
    * on intro_circ. */
   ip = find_desc_intro_point_by_ident(intro_circ->hs_ident, desc);
-  if (BUG(ip == NULL)) {
-    /* If we can find a descriptor from this introduction circuit ident, we
-     * must have a valid intro point object. Permanent error. */
+  if (ip == NULL) {
+    /* The following is possible if the descriptor was changed while we had
+     * this introduction circuit open and waiting for the rendezvous circuit to
+     * be ready. Which results in this situation where we can't find the
+     * corresponding intro point within the descriptor of the service. */
+    log_info(LD_REND, "Unable to find introduction point for service %s "
+                      "while trying to send an INTRODUCE1 cell.",
+             safe_str_client(onion_address));
     goto perm_err;
   }