[PATCH fifo 1/2] Cygwin: FIFO: avoid crashes when cloning a client

Ken Brown kbrown@cornell.edu
Mon Mar 25 23:06:00 GMT 2019


fhandler_fifo::clone called fhandler_base::clone on each client
fhandler.  But those fhandlers are actually fhandler_fifo objects, so
when fhandler_base::clone calls copyto, it's actually
fhandler_fifo::copyto that gets called.  This can lead to mysterious
crashes.

Fix this by simply calling clone (which translates to
fhandler_fifo::clone) on each client fhandler.
---
 winsup/cygwin/fhandler.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/winsup/cygwin/fhandler.h b/winsup/cygwin/fhandler.h
index f6982f0ba..ef34f9c40 100644
--- a/winsup/cygwin/fhandler.h
+++ b/winsup/cygwin/fhandler.h
@@ -1316,7 +1316,7 @@ public:
     fhandler_fifo *fhf = new (ptr) fhandler_fifo (ptr);
     copyto (fhf);
     for (int i = 0; i < nclients; i++)
-      fhf->client[i].fh = client[i].fh->fhandler_base::clone ();
+      fhf->client[i].fh = client[i].fh->clone ();
     return fhf;
   }
 };
-- 
2.17.0



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