commit 21f984cedec1c613218480bc3eb5e92349a7a812
author Kun Qin <kun.q@outlook.com> Sat Nov 21 06:24:32 2020 +0800
committer mergify[bot] <37929162+mergify[bot]@users.noreply.github.com> Thu Nov 26 03:22:24 2020 +0000
tree 9a0c22453eca145dc2ba843cd81ea00c3d4dca8a
parent e9d62effa37ea13fe04fc89b21d2de7776f183a2

CryptoPkg: BaseCryptLib: Fix buffer double free in CryptPkcs7VerifyEku

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=2459

SignerCert is part of Pkcs7 instance when both have valid content. OpenSLL
PKCS7_free function will release the memory of SignerCert when applicable.
Freeing SignerCert with X509_free again might cause page fault if use-
after-free guard is enabled.

Cc: Jian J Wang <jian.j.wang@intel.com>
Cc: Xiaoyu Lu <xiaoyux.lu@intel.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Guomin Jiang <guomin.jiang@intel.com>

Signed-off-by: Kun Qin <kun.q@outlook.com>
Reviewed-by: Jiewen Yao <Jiewen.yao@intel.com>

CryptoPkg/Library/BaseCryptLib/Pk/CryptPkcs7VerifyEku.c

diff --git a/CryptoPkg/Library/BaseCryptLib/Pk/CryptPkcs7VerifyEku.c b/CryptoPkg/Library/BaseCryptLib/Pk/CryptPkcs7VerifyEku.c
index c9fdb65..40cc39a 100644
--- a/CryptoPkg/Library/BaseCryptLib/Pk/CryptPkcs7VerifyEku.c
+++ b/CryptoPkg/Library/BaseCryptLib/Pk/CryptPkcs7VerifyEku.c
@@ -508,10 +508,6 @@
     free (SignedData);

   }

 

-  if (SignerCert != NULL) {

-    X509_free (SignerCert);

-  }

-

   if (Pkcs7 != NULL) {

     PKCS7_free (Pkcs7);

   }