Fix possible memory leak.

crypto/pkcs7/pk7_smime.c

@@ -3,7 +3,7 @@
  * project.
  */
 /* ====================================================================
- * Copyright (c) 1999-2003 The OpenSSL Project.  All rights reserved.
+ * Copyright (c) 1999-2004 The OpenSSL Project.  All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -329,10 +329,6 @@ STACK_OF(X509) *PKCS7_get0_signers(PKCS7 *p7, STACK_OF(X509) *certs, int flags)
 		PKCS7err(PKCS7_F_PKCS7_GET0_SIGNERS,PKCS7_R_WRONG_CONTENT_TYPE);
 		return NULL;
 	}
-	if(!(signers = sk_X509_new_null())) {
-		PKCS7err(PKCS7_F_PKCS7_GET0_SIGNERS,ERR_R_MALLOC_FAILURE);
-		return NULL;
-	}
 
 	/* Collect all the signers together */
 
@@ -343,6 +339,11 @@ STACK_OF(X509) *PKCS7_get0_signers(PKCS7 *p7, STACK_OF(X509) *certs, int flags)
 		return 0;
 	}
 
+	if(!(signers = sk_X509_new_null())) {
+		PKCS7err(PKCS7_F_PKCS7_GET0_SIGNERS,ERR_R_MALLOC_FAILURE);
+		return NULL;
+	}
+
 	for (i = 0; i < sk_PKCS7_SIGNER_INFO_num(sinfos); i++)
 	{
 	    si = sk_PKCS7_SIGNER_INFO_value(sinfos, i);