Avoid modifying input on failure in X509_(TRUST|PURPOSE)_add.

If X509_TRUST_add() or X509_PURPOSE_add() fail, they will leave the
object in an inconsistent state since the name is already freed.
This commit avoids changing the original name unless the *_add() call
will succeed.

Based on BoringSSL's commit: ab2815eaff6219ef57aedca2f7b1b72333c27fd0

ok miod@

1 files changed, 8 insertions, 6 deletions

diff --git a/src/lib/libcrypto/x509/x509_trs.c b/src/lib/libcrypto/x509/x509_trs.c
index 95fb568c68..4fa9f81ee7 100644
--- a/src/lib/libcrypto/x509/x509_trs.c
+++ b/src/lib/libcrypto/x509/x509_trs.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: x509_trs.c,v 1.18 2014/11/18 03:28:05 tedu Exp $ */
+/* $OpenBSD: x509_trs.c,v 1.19 2014/12/06 19:26:37 doug Exp $ */
 /* Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL
  * project 1999.
  */
@@ -177,6 +177,7 @@ X509_TRUST_add(int id, int flags, int (*ck)(X509_TRUST *, X509 *, int),
 {
         int idx;
         X509_TRUST *trtmp;
+        char *name_dup;
 
         /* This is set according to what we change: application can't set it */
         flags &= ~X509_TRUST_DYNAMIC;
@@ -199,12 +200,14 @@ X509_TRUST_add(int id, int flags, int (*ck)(X509_TRUST *, X509 *, int),
                 }
         }
 
+        if ((name_dup = strdup(name)) == NULL)
+                goto err;
+
         /* free existing name if dynamic */
         if (trtmp->flags & X509_TRUST_DYNAMIC_NAME)
                 free(trtmp->name);
         /* dup supplied name */
-        if ((trtmp->name = strdup(name)) == NULL)
-                goto err;
+        trtmp->name = name_dup;
         /* Keep the dynamic flag of existing entry */
         trtmp->flags &= X509_TRUST_DYNAMIC;
         /* Set all other flags */
@@ -226,10 +229,9 @@ X509_TRUST_add(int id, int flags, int (*ck)(X509_TRUST *, X509 *, int),
         return 1;
 
 err:
-        if (idx == -1) {
-                free(trtmp->name);
+        free(name_dup);
+        if (idx == -1)
                 free(trtmp);
-        }
         X509err(X509_F_X509_TRUST_ADD, ERR_R_MALLOC_FAILURE);
         return 0;
 }