From: Volker Lendecke <Volker.Lendecke@SerNet.DE>
Date: Wed, 19 Dec 2007 12:48:49 +0000 (+0100)
Subject: Samba Shared Repository - branch v3-2-test updated - initial-v3-2-unstable-716-g12cce3b
X-Git-Tag: samba-4.0.0alpha6~801^2~4019
X-Git-Url: http://git.samba.org/?a=commitdiff_plain;h=873b6f0f21e61be6e4f7084fc0ded768dfa077ab;p=samba.git

Samba Shared Repository - branch v3-2-test updated - initial-v3-2-unstable-716-g12cce3b

On Tue, Dec 18, 2007 at 06:04:32PM -0600, Jeremy Allison wrote:
>     Fix valgrind error in dbwrap_rbt where rec_priv->node was
>     being accessed after free. VALOKER PLEASE CHECK THIS VERY
>     CAREFULLY !!!! This is a correct fix in that it fixes the
>     valgrind error, but it looks inelegant to me. I think if
>     I understood this code better I could craft a more subtle
>     fix. Still looking at it....

Thanks a lot. Fully correct. What about the attached little
simplification?

Volker
(This used to be commit 5b72828600fb057a7aeb5f1a6fb6c23c23f28cd8)
---

diff --git a/source3/lib/dbwrap_rbt.c b/source3/lib/dbwrap_rbt.c
index 468b9405eee..93d73f29d13 100644
--- a/source3/lib/dbwrap_rbt.c
+++ b/source3/lib/dbwrap_rbt.c
@@ -68,8 +68,6 @@ static NTSTATUS db_rbt_store(struct db_record *rec, TDB_DATA data, int flag)
 
 	TDB_DATA this_key, this_val;
 
-	bool del_old_keyval = false;
-
 	if (rec_priv->node != NULL) {
 
 		/*
@@ -97,7 +95,11 @@ static NTSTATUS db_rbt_store(struct db_record *rec, TDB_DATA data, int flag)
 		 */
 
 		rb_erase(&rec_priv->node->rb_node, &rec_priv->db_ctx->tree);
-		del_old_keyval = true;
+
+		/*
+		 * Keep the existing node around for a while: If the record
+		 * existed before, we reference the key data in there.
+		 */
 	}
 
 	node = (struct db_rbt_node *)SMB_MALLOC(
@@ -105,9 +107,7 @@ static NTSTATUS db_rbt_store(struct db_record *rec, TDB_DATA data, int flag)
 		+ data.dsize);
 
 	if (node == NULL) {
-		if (del_old_keyval) {
-			SAFE_FREE(rec_priv->node);
-		}
+		SAFE_FREE(rec_priv->node);
 		return NT_STATUS_NO_MEMORY;
 	}
 
@@ -119,11 +119,9 @@ static NTSTATUS db_rbt_store(struct db_record *rec, TDB_DATA data, int flag)
 	db_rbt_parse_node(node, &this_key, &this_val);
 
 	memcpy(this_key.dptr, rec->key.dptr, node->keysize);
-	memcpy(this_val.dptr, data.dptr, node->valuesize);
+	SAFE_FREE(rec_priv->node);
 
-	if (del_old_keyval) {
-		SAFE_FREE(rec_priv->node);
-	}
+	memcpy(this_val.dptr, data.dptr, node->valuesize);
 
 	parent = NULL;
 	p = &rec_priv->db_ctx->tree.rb_node;