librbd: protect list_children from invalid child pool IoCtxs

While listing child images, don't ignore error codes returned
from librados when creating an IoCtx. This will prevent seg
faults from occurring when an invalid IoCtx is used.

Fixes: #10123
Backport: giant, firefly, dumpling
Signed-off-by: Jason Dillaman <dillaman@redhat.com>
(cherry picked from commit 0d350b6817d7905908a4e432cd359ca1d36bab50)

diff --git a/src/librbd/internal.cc b/src/librbd/internal.cc
index afa466025327e154be8816f156dbeb47a8ee0130..bf57f67a25eee4a39178178fa96ae9437056e73f 100644 (file)
--- a/src/librbd/internal.cc
+++ b/src/librbd/internal.cc
@@ -419,7 +419,12 @@ namespace librbd {
     for (std::list<string>::const_iterator it = pools.begin();
         it != pools.end(); ++it) {
       IoCtx ioctx;
-      rados.ioctx_create(it->c_str(), ioctx);
+      r = rados.ioctx_create(it->c_str(), ioctx);
+      if (r < 0) {
+        lderr(cct) << "Error accessing child image pool " << *it << dendl;
+        return r;
+      }
+
       set<string> image_ids;
       int r = cls_client::get_children(&ioctx, RBD_CHILDREN,
                                       parent_spec, image_ids);