Juan Lang : crypt32: Avoid reading freed memory when encountering a cyclic chain.

[Alexandre Julliard]

Module: wine
Branch: master
Commit: 4817fbc362daa4474e72874eb714dc387ed2e3f8
URL:    http://source.winehq.org/git/wine.git/?a=commit;h=4817fbc362daa4474e72874eb7...

Author: Juan Lang <juan.lang(a)gmail.com>
Date:   Tue Feb 24 16:55:00 2009 -0800

crypt32: Avoid reading freed memory when encountering a cyclic chain.

---

 dlls/crypt32/chain.c |    6 ++++++
 1 files changed, 6 insertions(+), 0 deletions(-)

diff --git a/dlls/crypt32/chain.c b/dlls/crypt32/chain.c
index 5943117..2e414cd 100644
--- a/dlls/crypt32/chain.c
+++ b/dlls/crypt32/chain.c
@@ -306,7 +306,13 @@ static BOOL CRYPT_AddCertToSimpleChain(PCertificateChainEngine engine,
                  = subjectInfoStatus;
             /* FIXME: initialize the rest of element */
             if (!(chain->cElement % engine->CycleDetectionModulus))
+            {
                 CRYPT_CheckSimpleChainForCycles(chain);
+                /* Reinitialize the element pointer in case the chain is
+                 * cyclic, in which case the chain is truncated.
+                 */
+                element = chain->rgpElement[chain->cElement - 1];
+            }
             CRYPT_CombineTrustStatus(&chain->TrustStatus,
              &element->TrustStatus);
             ret = TRUE;