From: Dave Barach <dave@barachs.net>
Date: Tue, 31 Jul 2018 14:39:30 +0000 (-0400)
Subject: Poison freed memory objects
X-Git-Tag: v18.10-rc1~509
X-Git-Url: https://gerrit.fd.io/r/gitweb?p=vpp.git;a=commitdiff_plain;h=1c7bf5d41737984907e8bad1dc832eb6cb1d6288

Poison freed memory objects

When compiled w/ -DCLIB_DEBUG=1, paint 0x13 across freed memory
blocks. Should result in a characteristic SIGSEGV if someone
dereferences a pointer in a freed vector element, etc.

Change-Id: I5f78970f4342310bfbe7adeddb56feff21f0de2c
Signed-off-by: Dave Barach <dave@barachs.net>
---

diff --git a/src/vppinfra/dlmalloc.c b/src/vppinfra/dlmalloc.c
index 8ae92cf566c..1bc8f656b66 100644
--- a/src/vppinfra/dlmalloc.c
+++ b/src/vppinfra/dlmalloc.c
@@ -4271,6 +4271,14 @@ void mspace_put (mspace msp, void *p_arg)
       mheap_put_trace ((u64)p_arg, psize);
     }
 
+#if CLIB_DEBUG > 0
+  /* Poison the object */
+  {
+    size_t psize = mspace_usable_size (object_header);
+    memset (object_header, 0x13, psize);
+  }
+#endif
+
   /* And free it... */
   mspace_free (msp, object_header);
 }